- Email: [email protected]
Somatic Morbidity Among Patients Diagnosed With Affective Psychoses and Paranoid Disorders
Somatic Morbidity Among Patients Diagnosed With Affective Psychoses and Paranoid Disorders A Case-Control Study A. B. DALMAU, M.D. B. K. BERGMAN, M.D., PH.D. B. G. BRISMAR, M.D., PH.D.
Several studies have shown an increased mortality rate among psychiatric patients. Morbidity, however, has been studied less often. In this study, the authors examined the number of hospitalizations with somatic diagnoses in 722 patients with affective psychoses and 472 with a paranoid disorder. Every patient had an age- and sex-matched control subject who did not have a psychiatric illness. Both groups of patients exhibited an increased number of somatic diagnoses compared with their control subjects, and this was true for the majority of the 14 different groups classified according to the International Classification of Diseases the authors studied. The pattern of somatic diagnoses was similar to that presented in one of the authors’ prior studies of schizophrenic patients. (Psychosomatics 1998; 39:253–262)
I
t is well known from several studies that a comorbidity exists between psychiatric and somatic diseases. Mortality is higher among patients with psychiatric illnesses, due not only to suicides and other violent causes, but also to natural causes.1 The conclusions drawn in the vast majority of the studies focusing on morbidity have been the same—an increase in somatic morbidity among patients with psychiatric disorders.2–8 The results are not easily compared, however, as different methods have been adopted. The definition of morbidity has varied and in different studies has been based on selfreports, screening laboratory tests, or somatic investigations.2–4,6–8 The findings probably represent a wide range of illness severity and they are not easy to separate relevant from less relevant findings. In a prior study,9 we analyzed somatic morbidity among patients who had schizophrenia. VOLUME 39 • NUMBER 3
• MAY–JUNE 1998
When comparing the numbers of hospitalizations with somatic diagnoses in the schizophrenic group with a control group, we found that the numbers of hospitalizations among the former were greater in 10 out of 14 groups diagnosed according to the International Classification of Diseases (ICD). One may speculate on the many different reasons for this excess morbidity. One interesting question is whether these findings are specific for schizophrenic patients or are a pattern common to all patients with psychiatric illness. The aim of this study was to Received March 14, 1997; revised September 11, 1997; accepted September 23, 1997. From the Department of Clinical Neuroscience and Family Medicine, Psychiatry Section; and A–Division 2, Karolinska Institute, Huddinge Hospital, Huddinge, Sweden. Address reprint requests to Dr. Bergman, Department of Psychiatry, M56, Karolinska Institute, Huddinge Hospital, S–14186 Huddinge, Sweden. Copyright 䉷 1998 The Academy of Psychosomatic Medicine.
253
Somatic Morbidity
elaborate the somatic morbidity in two other groups of patients diagnosed with severe psychiatric illnesses, namely patients diagnosed with affective psychoses and paranoid disorders. MATERIAL AND METHODS During a 3.5-year period (January 1, 1991–June 30, 1994), 5,497 patients were hospitalized at the Department of Psychiatry at Huddinge Hospital in Stockholm, Sweden. One hundred of these did not have a residence permit and were excluded from further analyses, as they lacked the civic registration numbers used to link the psychiatric and somatic treatments received. Information on all somatic and psychiatric inpatient care in public hospitals in Stockholm for the remaining 5,397 patients during a 15-year period (1981–1995) was collected from the Stockholm County Council computer files. Every time a patient is discharged from a Swedish hospital, this information is inputted into a central database register that contains information about each patient, including the patient’s name, place of residence, date of admission and discharge, name of hospital and department, and diagnoses. Regular controls of the quality of this database are performed by the National Board of Health and Welfare. Generally, the quality is good,10 the incidence of missing data is very low (only about 0%–1.5%). This register is based on the patient’s civic registration number, which contains 10 digits indicating date of birth and sex. The number is unique for each Swedish citizen and makes it possible, for example, to identify him/her in different registries. At Huddinge Hospital, 722 patients had been hospitalized during the 15-year study period with the diagnosis affective psychosis (ICD-8th Edition [ICD-8] and ICD-9th Edition [ICD-9]⳱296) at least once, and 472 others had been hospitalized with the diagnosis paranoid disorder (ICD-8 and ICD-9 ⳱297).11,12 All patients with these diagnoses were included, irrespectively of whether the diagnosis had been made on a psychiatric or a somatic ward and irrespectively of whether the diagnosis was the first diagnosis or a subdiagnosis. Each patient 254
could have up to six different diagnoses during one hospitalization. The classification of the somatic diseases followed the main groups in ICD-8 and ICD-9. The ICD group “diseases of the nervous system and sense organs” has been split into two to make it possible to study the diseases of the nervous system separately. From the group “genitourinary diseases,” we have excluded partus normalis, complications during partus, and abortion. These are included in the group “other diseases,” together with diagnoses from ICD Chapters IV, XIV, and XV (hematological diseases, congenital abnormalities, and conditions originating in the perinatal period). The group “neoplasm” corresponds to the entire ICD chapter, thus including both malignant and benign tumors. The group “injuries ” includes suicide attempts and other self-inflicted injuries, injuries caused by others, and accidental injuries. In total, 14 ICD groups have been dichotomized (yes/ no). If a patient, during hospitalization on a somatic or a psychiatric ward, received, for example, the diagnosis of diabetes mellitus, he/ she was classified as having an endocrine disease (even if it appeared as the third or fourth diagnosis). Thus, each patient could appear in several somatic diagnostic groups. A control group of equal size to the patient group was obtained by combining the national registration (containing personal and geographical data on all citizens) and the inpatient health care register in the Stockholm County Council files described earlier (these two files are also based on the civic registration numbers). The criteria for selecting the control subjects was that the control subject was matched pair-wise to each patient for age and gender, residence in the same geographical area of Stockholm, and no prior hospitalization for any psychiatric diagnosis during the 15-year period in question. Their control subjects’ consumption of inpatient care in Greater Stockholm from 1981 to 1995 was ascertained in the same way as for the study patients. We have separately analyzed the somatic diagnostic pattern among the patients who had never (during the 15-year period) been diagPSYCHOSOMATICS
Dalmau et al.
nosed with substance abuse. Of the 722, 590 were diagnosed as having an affective psychosis (82%), and 333 (71%) of the 472 patients were diagnosed with a paranoid disorder but had never been hospitalized due to a substance abuse disorder (ICD 303–305). As one of the criteria for the selection to the control group was that the person could not have been hospitalized with a psychiatric diagnosis that could not by definition be a diagnosis of substance abuse. Huddinge Hospital is one of the two university hospitals in Stockholm. The Department of Psychiatry serves a catchment area of 340,000 inhabitants, corresponding to about one-fifth of the total population of the region (1,700,000 in Greater Stockholm in 1993). In the catchment area, a high proportion of the residents are immigrants (about 20%). The level of income and education is relatively low among the residents compared with that in other areas of Stockholm. Private hospitals are very few in Sweden, and private inpatient treatment for psychiatric illness is extremely rare. Private health insurance coverage is not common, as the health care system is financed by taxes and provides health care for all citizens regardless of income. Statistics Comparisons between the case subjects and control subjects have been performed by determining the odds ratio with a 95% confidence interval. The chi-square test (two-tailed) has been used when calculating the statistical significance for distribution of gender. A Wilcoxon matched-pairs signed-ranks test (presented as Zvalues) was used for the results on the numbers of somatic diagnostic groups among the patients and control subjects. The correlation between year of birth and number of different somatic diagnostic groups has been calculated with Pearson’s correlation coefficient. The SPSS (Statistical Package for the Social Sciences) software, a Windows-based software package, was used for statistical calculations. RESULTS Hospitalizations for somatic illness were significantly more common in both groups of patients VOLUME 39 • NUMBER 3
• MAY–JUNE 1998
compared with the control subjects. Of the 722, 559 patients (77%) had been diagnosed with an affective psychosis, and 355 of the 472 paranoid patients (75%) had been diagnosed with a somatic disease, compared with 49% (P⬍0.001, v2⳱123.0, df⳱1) and 47 % (P⬍0.001, v2⳱72.7, df⳱1) of the control subjects, respectively. The difference between affective and paranoid patients was not significant. Fifty-seven percent of the patients diagnosed with affective disorders and 55% of the paranoid patients were females (Table 1). The female patients had been hospitalized with somatic diagnoses more often than the males, and the difference was most pronounced among those with affective disorders. In this group, 83% of the women had received a somatic diagnosis during hospitalization, compared with 70% of the men (P⬍0.001, v2⳱18.6, df⳱1). In the group of paranoid patients, 79% of the women and 71% of the men had somatic diagnoses (P⳱0.043, v2⳱4.1, df⳱1). In both groups, the somatically ill patients were on average older than the patients without somatic diagnoses. For the patients with an af-
TABLE 1.
Numbers of patients with affective psychoses and paranoid disorders, in total and with the exclusion of substance abuse, schizophrenia, and all other psychiatric diagnoses
All patients Men Women Patients without substance abuse Men Women Patients without schizophrenia Men Women Patients without any other psychiatric diagnoses Men Women
Affective psychoses n (%)
Paranoid disorders n (%)
722 (100) 310 (43) 412 (57)
472 (100) 212 (45) 260 (55)
590 (82) 221 (37.5) 369 (62.5)
333 (71) 111 (33.3) 222 (66.7)
546 (76) 233 (42.7) 313 (57.3)
342 (72) 137 (40.1) 205 (59.9)
123 (17) 55 (44.7) 68 (55.3)
84 (18) 23 (27.4) 61 (72.6)
255
Somatic Morbidity
fective illness without a somatic diagnosis, the mean year of birth was 1949 (standard deviation [SD]⳱16), compared with 1941 (SD⳱13) for the somatically ill patients (t⳱5.28, P⬍0.001). For the patients with a paranoid disorder, the corresponding years were 1944 (SD⳱18) and 1952 (SD⳱12), respectively (t⳱4.94, P⬍ 0.001). The correlation between year of birth and number of different somatic diagnostic groups was significant for both groups for the affective patients: (r⳱ⳮ0.32, P⬍0.001) and for the paranoid patients (r⳱ⳮ0,40, P⬍0.001). The patients with affective psychosis received this diagnosis in 3,377 hospitalizations, 3,233 of which were established on a psychiatric ward and the rest on various somatic wards. Of the 3,233 hospitalizations on psychiatric wards, 78 patients (10.8 % of all patients diagnosed with affective psychosis) received 1 or more somatic diagnoses in 145 hospitalizations. The patients with paranoid psychosis received this diagnosis in 1,369 hospitalizations, 1,320 of which were on psychiatric wards. Forty-seven different paranoid patients (10.0 %) received a somatic diagnosis in a total of 83 of the 1,320 hospitalizations. The numbers of hospitalizations with somatic diagnoses was increased compared with that of the control subjects, both in the group composed of patients diagnosed with affective psychoses and the group diagnosed with paranoid disorders (Table 2). The numbers of hospitalizations were significantly increased in 11 out of 14 ICD groups among the affective patients. The exceptions were tumors, diseases of the musculoskeletal system, and diseases of the sense organs. For the paranoid group, the number of hospitalizations showed a significant increase in 10 of the 14 ICD groups. No differences between the case subjects and control subjects were found in the same diagnostic groups, as mentioned earlier, and neither in the group “other diseases.” Measured in absolute numbers, the affective disorder patients appeared 1,618 times in the 14 diagnostic groups, compared with 696 times for their control subjects. The figures for the patients with paranoid psychoses were 1,019 and 437 for their control 256
subjects. (For the calculations of the aforementioned numbers, every single patient could give rise to 1 diagnosis in each of the 14 different ICD groups.) In the paranoid group, when excluding the patients with substance abuse, the significant differences between the patients and control subjects disappeared for the groups of gastrointestinal and genitourinary diseases, thus resulting in an excess number of somatic hospitalizations in 8 of the 14 ICD groups. No differences were noted in the affective group between the patients who had been diagnosed with a substance abuse at least once and those who had not (Table 3). As there were 14 somatic diagnostic groups, each patient and control subject could theoretically be found in every group. However, this was not the case. The affective disorder patients appeared in 0–10 groups (first percentile⳱1, second percentile⳱2, third percentile⳱4) and their control subjects in 0–8 groups (percentiles 1, 2, and 3⳱ 0, 0, 1, respectively (Z⳱ⳮ13.1, P⬍0.001). For the paranoidpatients and control subjects, the figures were similar, with the same distribution in the groups (0–10 and 0–8, respectively). The percentiles 1–3 were as follows: 1, 5, 4 for the patients and 0, 0, 1 for control subjects (Z⳱ⳮ10.0, P⬍0.001). After the exclusion of the patients who had received a diagnosis of schizophrenia, 546 affective and 342 paranoid patients remained. The principal results presented in Table 2 were not changed. This was true for all the somatic ICD groups. An analysis was also performed for the “pure” psychiatric groups, that is, for the patients with no other psychiatric diagnoses registered apart from affective psychosis or paranoid disorder during the 15-year period (Table 4). In the former group (composed of 123 individuals), the patients had received at least 1 somatic diagnosis more often than the control subjects, but in the second group (n⳱84), no significant differences were observed between the patients and control subjects. DISCUSSION The patients with affective psychoses as well as those with paranoid disorders showed an inPSYCHOSOMATICS
Dalmau et al.
creased number of hospitalizations with somatic diagnoses compared with their matched control subjects. In principle, the two psychiatric diagTABLE 2.
noses correlated with the same groups of somatic diseases. Thus, the increase in somatic hospitalizations appeared in 11 and 10 of the 14
The probability of receiving somatic diagnoses for the patients with affective psychoses and paranoid disorders Affective Psychoses
Diseases (ICD-8/ICD-9) Infectious and parasitic diseases Neoplasm Endocrine diseases Diseases of the respiratory system Diseases of the circulatory system Diseases of the genitourinary system Diseases of the digestive system Diseases of the nervous system Diseases of the sense organs Diseases of the musculoskeletal system and connective tissue Diseases of the skin and subcutaneous tissue Injuries Symptoms. signs. and ill-defined conditions Other diseases
Paranoid Disorders
Odds Ratio
Confidence Interval
Odds Ratio
Confidence Interval
3.03 1.35 2.95 2.36 1.85 2.13 2.25 3.71 0.76
1.96–4.67 0.92–1.98 1.97–4.42 1.62–3.44 1.38–2.49 1.62–2.82 1.64–3.09 2.18–6.31 0.39–1.46
3.84 1.57 4.14 1.95 2.18 1.71 1.99 7.00 1.70
2.24–6.57 0.95–2.59 2.36–7.27 1.21–3.15 1.47–3.23 1.20–2.42 1.35–2.92 3.46–14.15 0.89–3.25
1.36 5.05 5.37 6.68 1.57
0.94–1.96 2.40–10.60 4.11–7.03 5.16–8.66 1.13–2.18
1.43 7.38 6.9 5.97 0.93
0.87–2.36 2.98–18.29 4.82–9.88 4.32–8.24 0.65–1.35
Note: Comparisons have been made with the matched control subjects and are expressed as odds ratios. Confidence intervals of 95% are used. ICD-8/ICD-9: International Classification of Diseases, 8th and 9th Editions. respectively.
TABLE 3.
The probability of receiving somatic diagnoses for patients with affective psychoses and paranoid disorders. who have had never had a diagnosis of substance abuse Affective Psychoses
Diseases (ICD-8/ICD-9) Infectious and parasitic diseases Neoplasm Endocrine diseases Diseases of the respiratory system Diseases of the circulatory system Diseases of the genito-urinary system Diseases of the digestive system Diseases of the nervous system Diseases of the sense organs Diseases of the musculoskeletal system and connective tissue Diseases of the skin and subcutaneous tissue Injuries Symptoms. signs. and ill-defined conditions Other diseases
Paranoid Disorders
Odds Ratio
Confidence Interval
Odds Ratio
Confidence Interval
2.14 1.25 2.72 1.88 1.72 2.09 1.89 3.50 0.78
1.31–3.50 0.84–1.84 1.78–4.16 1.24–2.85 1.26–2.36 1.54–2.85 1.33–2.68 1.89–6.50 0.40–1.56
2.42 1.56 4.28 1.78 1.87 1.34 1.53 8.14 1.57
1.29–4.55 0.89–2.72 2.21–8.31 1.01–3.14 1.20–2.92 0.90–2.01 0.97–2.40 3.32–19.99 0.65–3.83
1.34 4.31 3.85 5.76 1.56
0.88–2.04 1.88–9.85 2.87–5.18 4.34–7.65 1.08–2.24
1.26 5.55 5.21 4.86 0.78
0.69–2.28 1.83–16.85 3.36–8.09 3.34–7.07 0.51–1.21
Note: Comparisons have been made with matched control subjects and are expressed as odds ratios. Confidence intervals of 95% are used. ICD-8/ICD-9: International Classification of Diseases, 8th and 9th Editions. respectively.
VOLUME 39 • NUMBER 3
• MAY–JUNE 1998
257
Somatic Morbidity
groups, respectively. The results are fairly similar to those presented previously for patients with schizophrenia.9 The differences between the schizophrenic patients and the present two groups were that tumors were overrepresented among the schizophrenic patients but not among the affective or paranoid patients and that the frequency of genitourinary diseases was similar to that of the control subjects among the schizophrenic patients and greater among the affective and paranoid patients. Concerning tumors, most studies have concentrated on their frequency among schizophrenic patients. Earlier studies showed an underrepresentation of cancer deaths among schizophrenic patients,13,14 but it has been suggested that this is best explained by methodological problems.15,16 Later studies have presented results ranging from a slight excess mortality in cancer17–19 to a small undermortality.20–23 To our knowledge, no comparisons between the incidence of cancer morbidity and mortality have been made among schizophrenic patients and patients with affective psychoses. Ghadirian and Engelsmann24 found an increased rate of physical illness in manic-depressive patients compared with schizophrenic patients in all surveyed groups of diseases, except for the gastrointestinal diseases. However, their study design differed from ours in many reTABLE 4.
The probability of receiving somatic diagnoses for patients with affective psychoses and paranoid disorders but no other psychiatric diagnoses registered during the 15-year period Affective Psychoses
Paranoid Disorders
Control Control Patients Subjects Patients Subjects Somatic disease No somatic disease Total Odds ratio Confidence interval (95%)
258
78
58
52
47
45 123
65 123
32 84
37 84
1.94
1.28
1.17–3.23
0.69–2.37
spects. Their study population included only outpatients, and as register data was not used information was obtained from interviews and a review of patient records. In an investigation by Fink,25 focusing on the number of hospitalizations during an 8-year period in a Danish population, 74% of the patients once hospitalized on a psychiatric ward had at least 1 hospitalization on a somatic ward as well. In the general population, 41% had been hospitalized on a somatic ward. There was an increased risk of admission to a general ward for all psychiatric diagnoses, except for schizophrenia. One of the most persistent findings in the literature is an increased mortality/morbidity due to cardiovascular diseases among patients with affective disorders,26–29 and this finding is in accordance with ours. Some authors have also noted an increased rate of respiratory diseases among patients with affective psychoses.26,29 In 1982, Linda˚gerd30 studied hospitalizations for the “depressive spectrum” of the entire male population in Gothenburg, a Swedish city of about 500,000 citizens. The “spectrum” included both uni- and bipolar disorders, and he found an increased number of hospitalizations due to infections, myocardial infarction, and asthma. In this study, an overrepresentation of endocrine diseases was found among the patients with affective psychoses as well as among those with paranoid disorders. The possibility of a positive association between affective disorders and diabetes mellitus has been addressed in many studies. Such an association has been claimed to exist for depressive states31 as well as for bipolar disorders.32 In the latter case, the possibility that lithium may contribute to the diabetic condition has attracted much attention. In a review article, Russel and Johnson33 concluded that both the affective disorder in itself and lithium could lead to the development of diabetes mellitus. Little has been published about paranoid disorders and their relationship to somatic diseases. It is apparent that this subject has attracted very little attention and the literature is limited. In some studies many different psychoses are PSYCHOSOMATICS
Dalmau et al.
put together in a group of “functional psychoses,” in which paranoid conditions are generally included.34 One article that has dealt specifically with paranoid disorders is that of Jo¨rgensen and Mortensen,35 who investigated diagnostic stability over time. For patients admitted for the first time with functional psychoses, paranoia was one of the most unstable diagnoses; half of the patients were classified differently at the latest re-admission. Diagnostic instability may influence the results, and to evaluate its importance we have analyzed our material, excluding all patients who at any time have had another psychiatric diagnosis than paranoid disorder (Table 4). In contrast to the patients with affective psychosis, the results among the paranoid patients changed, and the differences noted between the patients and control subjects were no longer significant. This finding is difficult to explain, but one may speculate that the diagnosis paranoid disorder has been used quite loosely. Another possible explanation is the small size of the group of “pure” paranoid patients. Also, a difference in the numbers of somatic hospitalizations is seen between patients with a single diagnosis and patients with multiple diagnoses, which may reflect a difference in the severity of psychiatric disease in these two patient groups. It might be that the difference between mixed and pure groups would disappear if mono- and polydiagnostic patients with equal numbers of psychiatric admissions were compared. The reason for the increased number of somatic hospitalizations among the psychiatric patients is probably multifactorial in nature. The first important question to ask is whether or not it reflects a true excess in somatic morbidity. Another explanation for the hospitalizations could be somatization and a greater tendency to seek medical care. We have noted an excessnumber of diagnoses of “symptoms, signs, and illdefined conditions,” which may be dependent on treatment-seeking behavior. The patients were hospitalized because of a wide range of diagnoses, however, and as the threshold for admittance to the hospital normally is fairly high, the adoptance of hospital admissions as a measure of morbidity should result in a rather strict defVOLUME 39 • NUMBER 3
• MAY–JUNE 1998
inition of that term. Other interpretations of the reasons for hospitalizations due to different somatic diagnoses have been given, however. Fink36 compared the diagnostic pattern of medical admissions among psychiatric patients and the general population and concluded that the most likely explanation for the excess number of admissions in the former group was different illness behavior, and not a true increase in morbidity. Further, another explanation for the increased number of somatic hospitalizations among our patients could be the fact that the patients are already within the health care system, which could lead to the detection of more diseases and abnormalities than otherwise. When a patient is admitted to a psychiatric ward, a physical investigation and laboratory tests are undertaken to detect somatic diseases that could be related to the psychiatric illness or its deterioration. Patients who debut with psychotic conditions are usually given a computed tomography head scan, and an electroencephalogram is done as well. We have accepted somatic diagnoses as somatic and psychiatric diagnoses as psychiatric, irrespectively of whether the patient was being treated on a somatic or psychiatric ward when the diagnosis was made. This should prevent underdiagnosis of somatic diseases, for example, when a patient, because of practical or psychological reasons, is admitted to a psychiatric ward when in need of somatic investigation or treatment, or when the same patient during psychiatric care gets a somatic disease. On the other hand, a certain amount of overdiagnosis may be expected, for example, when the somatic disease would not have warranted admission to a somatic ward if the patient did not already have a psychiatric illness, or if a psychiatric patient happens to have a somatic disease that is noted as a subdiagnosis in the patient record. To give some indication of the possible extent of overdiagnosing we have looked at the total number of hospitalizations on psychiatric wards where one diagnosis was either affective psychosis or paranoid disorder, and the other somatic. For both groups, about 10% of the pa259
Somatic Morbidity
tients had received a somatic diagnosis when hospitalized on a psychiatric ward. In some cases, this disease may not per se have led to inpatient somatic care, and in other cases the opposite may be true. Our material does not allow us to estimate the proportions between these possibilities. However, it seems improbable that this factor has affected the main results presented in this study. The substance abuse disorders are known to be related to both psychiatric and somatic diseases.37,38 In our material, about 29% of the patients with paranoid disorders had a diagnosis of substance abuse. This contrasts with the 18% in the group with affective psychoses. This difference is hard to interpret, and we have not been able to find any relevant studies in the literature. The control group consists of persons without psychiatric diagnoses, which means that they, by definition, have no known substance abuse history. Therefore, we have separately analyzed the results for the patients with and without substance abuse. When excluding the former, we still found a significant difference between the patients and control subjects in most of the somatic ICD groups (Table 3). For the affective group, this procedure did not lead to any differences in the results. In the paranoid group, the number of groups with an excess number of hospitalizations with somatic diagnoses decreased from 10 to 8; the differences seen between the patients and control subjects in the groups of gastrointestinal and genitourinary diseases disappeared. Other important environmental factors related to somatic morbidity are smoking and diet. It is well known that patients with psychiatric disorders smoke more than others.39 It is also
possible that their dietary habits differ from persons without psychiatric disorders, thus increasing the risk of certain somatic diseases. It would have been interesting to analyze how these environmental factors, and also social factors, as for example, social isolation, unmarried status, and unemployment, were distributed among our patients and control subjects. However, in a register study of this type this is not possible. Suicides and suicide attempts are registered in the group of injuries. As suicide attempts may be a manifestation of psychiatric disease the results in this group might reflect psychiatric morbidity rather than somatic morbidity. A higher than expected incidence of atopic disorders has been discovered among patients with bipolar disorders.29,40 The same is also true for diabetes mellitus.32,33 This could indicate the presence of a common etiology, possibly of a genetic character. Genetic factors are known to play a role in the etiology of all these diseases.41–44 It has also been proposed that there is an inverse relationship between Down’s syndrome and bipolar affective disorders,45 which may also lead to speculations concerning genetic associations. This study has shown that patients diagnosed with affective and paranoid conditions show an increased number of hospitalizations with somatic diagnoses and that their somatic diagnostic pattern is the same as for schizophrenic patients. We find it reasonable to believe that this increase reflects an increase in somatic morbidity. There is a need for further investigations among patients with less severe psychiatric illnesses. Another intriguing question is that of whether somatic morbidity differs before and after the debut of a psychiatric illness.
References
1. Corten PH, Ribourdoille M, Hermann P, et al: Epidemiological survey of the “Natural” mortality in psychiatry. Acta Psychiatr Belg 1988; 88:349–371 2. Eastwood MR, Trevelyan MH: Relationship between physical and psychiatric disorder. Psychol Med 1972; 2:363–372 3. Murphy JM, Monson RR, Olivier DC, et al: Relations 260
over time between psychiatric and somatic disorders: the Stirling County Study. Am J Epidemiol 1992; 136:95–105 4. Koranyi EK: Morbidity and rate of undiagnosed physical illnesses in a psychiatric clinic population. Arch Gen Psychiatry 1979; 36:414–419 5. Shapiro S, Skinner EA, Kessler LG, et al: Utilization PSYCHOSOMATICS
Dalmau et al.
of health and mental health services.Arch Gen Psychiatry 1984; 41:971–978 6. Eastwood MR, Mindham RHS, Tennent TG: The physical status of psychiatric emergencies. Br J Psychiatry 1970; 116:545–550 7. Maricle RA, Hoffman WF, Bloom JD: The prevalence and significance of medical illness among chronically mentally ill outpatients. Community Mental Health Journal 1987; 23:81–90 8. Wells KB, Golding JM, Burnam MA: Chronic medical conditions in a sample of the general population with anxiety, affective and substance abuse disorders. Am J Psychiatry 1989; 146:1440–1445 9. Dalmau A, Bergman B, Brismar B: Somatic morbidity in schizophrenia—a case control study. Public Health 1997; 111:393–397 10. Patientregistret, 1987–1995. Kvalitet och inneha˚ll. Epidemiologiskt centrum, Socialstyrelsen Stockholm, 1997 11. Westerholm B (ed): Swedish version of International Classification of Diseases, Eighth Revision, 1982 12. Sandlund M-B (ed): Swedish version of International Classification of Diseases, Ninth Revision, 1986 13. Katz J, Kunofsky S, Patton RE, et al: Cancer mortality among patients in New York mental hospitals. Cancer 1967; 20:2194–2199 14. Rassidakis NC, Kelepouris M, Goulis K, et al: On the incidence of malignancy among schizophrenic patients. Agressologie 1973; 14:269–273 15. Fox BH: Cancer death risk in hospitalized mental patients. Science 1978; 201:966–968 16. Scheflen AE: Malignant tumors in the institutionalized psychotic population. AMA Archives of Neurology and Psychiatry 1951: 65:145–155 17. Nakane Y, Ohta Y: The example of linkage with a cancer register, in Psychiatric Case Registers in Public Health: A Worldwide Inventory 1960–1985, edited by ten Horn GH, Giel R , Gulbinat WH, Henderson JH, et al. Amsterdam, The Netherlands, Elsevier Science Publishers B.V., 1986, pp. 240–245 18. Craig TJ, Lin SP: Cancer and mental illness. Compr Psychiatry 1981; 22:404–410. 19. Allebeck P, Wistedt B: Mortality in schizophrenia. Arch Gen Psychiatry 1986; 43:650–653 20. Wood JB, Evenson RC, Cho DW, et al: Mortality variations among public mental health patients. Acta Psychiatr Scand 1985; 72:218–229 21. Brook OH: Mortality in the long-stay population of Dutch mental hospitals. Acta Psychiatr Scand 1985; 71:626–635 22. Giel R, Dijk S, van Weerden-Dijkstra JR: Mortality in the long-stay population of all Dutch mental hospitals. Acta Psychiatr Scand 1978; 57:361–368 23. Mortensen PB: The occurrence of cancer in first admitted schizophrenic patients. Schizophr Res 1994; 12:185–194 24. Ghadirian AM, Engelsmann F: Somatic illness in VOLUME 39 • NUMBER 3
• MAY–JUNE 1998
manic-depressive and schizophrenic patients. J Psychosom Res 1985; 29:281–286 25. Fink P: Psychiatric and somatic comorbidity: the general population’s utilization of hospital admissions (thesis). Institute of Basic Psychiatric Research, Department of Psychiatric Demography, Psychiatric Hospital, Aarhus, Denmark, 1992, ISBN 87–90017–46–3 26. Sharma R, Markar HR: Mortality in affective disorder. J Affect Disord 1994; 31:91–96 27. Weeke A, Juel K, Vaeth M: Cardiovascular death and manic-depressive psychosis. J Affect Disord 1987; 13:287–292 28. Murphy JM, Monson RR, Olivier DC: Affective disorders and mortality. Arch Gen Psychiatry 1987; 44:473–480 29. Baldwin JA: Schizophrenia and physical disease: a preliminary analysis of the data from the Oxford Record Linkage Study, in Biochemistry of Schizophrenia and Addiction, edited by Hemmings G. Lancaster, UK, MTP Press, 1980, pp. 297–318 30. Lindega˚rd B: Physical illness in severe depressives and psychiatric alcoholics in Gothenburg, Sweden. J Affect Disord 1982; 4:383–393 31. Gavard JA, Lustman PJ, Clouse RE: Prevalence of depression in adults with diabetes. Diabetes Care 1993; 16:1167–1178 32. Lilliker SL: Prevalence of diabetes in a manic-depressive population. Compr Psychiatry 1980; 21:270–275 33. Russel JD, Johnson GFS: Affective disorders, diabetes mellitus and lithium. Aust N Z J Psychiatry 1981; 15:349–353 34. Hewer W, Ro¨ssler W, Fatkenheuer B: Mortality among patients in psychiatric hospitals in Germany. Acta Psychiatr Scand 1995; 91:174–179 35. Jorgensen P, Mortensen PB: Admission pattern and diagnostic stability of patients with functional psychoses in Denmark during a two-year observation period. Acta Psychiatr Scand 1988; 78:361–365 36. Fink P: Physical disorders associated with mental illness: a register investigation. Psychol Med 1990; 20:829–834 37. Regier DA, Farmer ME, Rae DS, et al: Comorbidity of mental disorders with alcohol and other drug abuse. JAMA 1990; 264:2511–2518 38. Kissin B, Begleiter H (eds): The Biology of Alcoholism: Clinical Pathology, Vol 3. New York, Plenum, 1974 39. Glassman AH: Cigarette smoking: implications for psychiatric illness. Am J Psychiatry 1993; 150:546– 553 40. Nasr S, Altman EG, Meltzer HY: Concordance of atopic and affective disorders. J Affect Disord 1981; 3:291–296 41. Kendler KS, Pedersen NL, Neale MC, et al: A pilot Swedish twin study of affective illness including hospital- and population-ascertained subsamples: results of model fitting. Behav Gen 1995; 25:217–232 261
Somatic Morbidity
42. Goodwin FK, Jamison KR: Manic-Depressive Illness. New York, Oxford University Press, 1990, pp. 376– 401 43. Blumenthal MN, Amos DB: Genetic and immunologic basis of atopic responses. Chest 1987; 91(suppl): 176S–184S
262
44. Kingston HM: Genetics of common disorders. BMJ 1989; 298:949–952 45. Craddock N, Owen M: Is there an inverse relationship between Down’s syndrome and bipolar disorder? Literature review and genetic implications. J Intellect Disabil Res 1994; 38:613–620
PSYCHOSOMATICS
Several studies have shown an increased mortality rate among psychiatric patients. Morbidity, however, has been studied less often. In this study, the authors examined the number of hospitalizations with somatic diagnoses in 722 patients with affective psychoses and 472 with a paranoid disorder. Every patient had an age- and sex-matched control subject who did not have a psychiatric illness. Both groups of patients exhibited an increased number of somatic diagnoses compared with their control subjects, and this was true for the majority of the 14 different groups classified according to the International Classification of Diseases the authors studied. The pattern of somatic diagnoses was similar to that presented in one of the authors’ prior studies of schizophrenic patients. (Psychosomatics 1998; 39:253–262)
I
t is well known from several studies that a comorbidity exists between psychiatric and somatic diseases. Mortality is higher among patients with psychiatric illnesses, due not only to suicides and other violent causes, but also to natural causes.1 The conclusions drawn in the vast majority of the studies focusing on morbidity have been the same—an increase in somatic morbidity among patients with psychiatric disorders.2–8 The results are not easily compared, however, as different methods have been adopted. The definition of morbidity has varied and in different studies has been based on selfreports, screening laboratory tests, or somatic investigations.2–4,6–8 The findings probably represent a wide range of illness severity and they are not easy to separate relevant from less relevant findings. In a prior study,9 we analyzed somatic morbidity among patients who had schizophrenia. VOLUME 39 • NUMBER 3
• MAY–JUNE 1998
When comparing the numbers of hospitalizations with somatic diagnoses in the schizophrenic group with a control group, we found that the numbers of hospitalizations among the former were greater in 10 out of 14 groups diagnosed according to the International Classification of Diseases (ICD). One may speculate on the many different reasons for this excess morbidity. One interesting question is whether these findings are specific for schizophrenic patients or are a pattern common to all patients with psychiatric illness. The aim of this study was to Received March 14, 1997; revised September 11, 1997; accepted September 23, 1997. From the Department of Clinical Neuroscience and Family Medicine, Psychiatry Section; and A–Division 2, Karolinska Institute, Huddinge Hospital, Huddinge, Sweden. Address reprint requests to Dr. Bergman, Department of Psychiatry, M56, Karolinska Institute, Huddinge Hospital, S–14186 Huddinge, Sweden. Copyright 䉷 1998 The Academy of Psychosomatic Medicine.
253
Somatic Morbidity
elaborate the somatic morbidity in two other groups of patients diagnosed with severe psychiatric illnesses, namely patients diagnosed with affective psychoses and paranoid disorders. MATERIAL AND METHODS During a 3.5-year period (January 1, 1991–June 30, 1994), 5,497 patients were hospitalized at the Department of Psychiatry at Huddinge Hospital in Stockholm, Sweden. One hundred of these did not have a residence permit and were excluded from further analyses, as they lacked the civic registration numbers used to link the psychiatric and somatic treatments received. Information on all somatic and psychiatric inpatient care in public hospitals in Stockholm for the remaining 5,397 patients during a 15-year period (1981–1995) was collected from the Stockholm County Council computer files. Every time a patient is discharged from a Swedish hospital, this information is inputted into a central database register that contains information about each patient, including the patient’s name, place of residence, date of admission and discharge, name of hospital and department, and diagnoses. Regular controls of the quality of this database are performed by the National Board of Health and Welfare. Generally, the quality is good,10 the incidence of missing data is very low (only about 0%–1.5%). This register is based on the patient’s civic registration number, which contains 10 digits indicating date of birth and sex. The number is unique for each Swedish citizen and makes it possible, for example, to identify him/her in different registries. At Huddinge Hospital, 722 patients had been hospitalized during the 15-year study period with the diagnosis affective psychosis (ICD-8th Edition [ICD-8] and ICD-9th Edition [ICD-9]⳱296) at least once, and 472 others had been hospitalized with the diagnosis paranoid disorder (ICD-8 and ICD-9 ⳱297).11,12 All patients with these diagnoses were included, irrespectively of whether the diagnosis had been made on a psychiatric or a somatic ward and irrespectively of whether the diagnosis was the first diagnosis or a subdiagnosis. Each patient 254
could have up to six different diagnoses during one hospitalization. The classification of the somatic diseases followed the main groups in ICD-8 and ICD-9. The ICD group “diseases of the nervous system and sense organs” has been split into two to make it possible to study the diseases of the nervous system separately. From the group “genitourinary diseases,” we have excluded partus normalis, complications during partus, and abortion. These are included in the group “other diseases,” together with diagnoses from ICD Chapters IV, XIV, and XV (hematological diseases, congenital abnormalities, and conditions originating in the perinatal period). The group “neoplasm” corresponds to the entire ICD chapter, thus including both malignant and benign tumors. The group “injuries ” includes suicide attempts and other self-inflicted injuries, injuries caused by others, and accidental injuries. In total, 14 ICD groups have been dichotomized (yes/ no). If a patient, during hospitalization on a somatic or a psychiatric ward, received, for example, the diagnosis of diabetes mellitus, he/ she was classified as having an endocrine disease (even if it appeared as the third or fourth diagnosis). Thus, each patient could appear in several somatic diagnostic groups. A control group of equal size to the patient group was obtained by combining the national registration (containing personal and geographical data on all citizens) and the inpatient health care register in the Stockholm County Council files described earlier (these two files are also based on the civic registration numbers). The criteria for selecting the control subjects was that the control subject was matched pair-wise to each patient for age and gender, residence in the same geographical area of Stockholm, and no prior hospitalization for any psychiatric diagnosis during the 15-year period in question. Their control subjects’ consumption of inpatient care in Greater Stockholm from 1981 to 1995 was ascertained in the same way as for the study patients. We have separately analyzed the somatic diagnostic pattern among the patients who had never (during the 15-year period) been diagPSYCHOSOMATICS
Dalmau et al.
nosed with substance abuse. Of the 722, 590 were diagnosed as having an affective psychosis (82%), and 333 (71%) of the 472 patients were diagnosed with a paranoid disorder but had never been hospitalized due to a substance abuse disorder (ICD 303–305). As one of the criteria for the selection to the control group was that the person could not have been hospitalized with a psychiatric diagnosis that could not by definition be a diagnosis of substance abuse. Huddinge Hospital is one of the two university hospitals in Stockholm. The Department of Psychiatry serves a catchment area of 340,000 inhabitants, corresponding to about one-fifth of the total population of the region (1,700,000 in Greater Stockholm in 1993). In the catchment area, a high proportion of the residents are immigrants (about 20%). The level of income and education is relatively low among the residents compared with that in other areas of Stockholm. Private hospitals are very few in Sweden, and private inpatient treatment for psychiatric illness is extremely rare. Private health insurance coverage is not common, as the health care system is financed by taxes and provides health care for all citizens regardless of income. Statistics Comparisons between the case subjects and control subjects have been performed by determining the odds ratio with a 95% confidence interval. The chi-square test (two-tailed) has been used when calculating the statistical significance for distribution of gender. A Wilcoxon matched-pairs signed-ranks test (presented as Zvalues) was used for the results on the numbers of somatic diagnostic groups among the patients and control subjects. The correlation between year of birth and number of different somatic diagnostic groups has been calculated with Pearson’s correlation coefficient. The SPSS (Statistical Package for the Social Sciences) software, a Windows-based software package, was used for statistical calculations. RESULTS Hospitalizations for somatic illness were significantly more common in both groups of patients VOLUME 39 • NUMBER 3
• MAY–JUNE 1998
compared with the control subjects. Of the 722, 559 patients (77%) had been diagnosed with an affective psychosis, and 355 of the 472 paranoid patients (75%) had been diagnosed with a somatic disease, compared with 49% (P⬍0.001, v2⳱123.0, df⳱1) and 47 % (P⬍0.001, v2⳱72.7, df⳱1) of the control subjects, respectively. The difference between affective and paranoid patients was not significant. Fifty-seven percent of the patients diagnosed with affective disorders and 55% of the paranoid patients were females (Table 1). The female patients had been hospitalized with somatic diagnoses more often than the males, and the difference was most pronounced among those with affective disorders. In this group, 83% of the women had received a somatic diagnosis during hospitalization, compared with 70% of the men (P⬍0.001, v2⳱18.6, df⳱1). In the group of paranoid patients, 79% of the women and 71% of the men had somatic diagnoses (P⳱0.043, v2⳱4.1, df⳱1). In both groups, the somatically ill patients were on average older than the patients without somatic diagnoses. For the patients with an af-
TABLE 1.
Numbers of patients with affective psychoses and paranoid disorders, in total and with the exclusion of substance abuse, schizophrenia, and all other psychiatric diagnoses
All patients Men Women Patients without substance abuse Men Women Patients without schizophrenia Men Women Patients without any other psychiatric diagnoses Men Women
Affective psychoses n (%)
Paranoid disorders n (%)
722 (100) 310 (43) 412 (57)
472 (100) 212 (45) 260 (55)
590 (82) 221 (37.5) 369 (62.5)
333 (71) 111 (33.3) 222 (66.7)
546 (76) 233 (42.7) 313 (57.3)
342 (72) 137 (40.1) 205 (59.9)
123 (17) 55 (44.7) 68 (55.3)
84 (18) 23 (27.4) 61 (72.6)
255
Somatic Morbidity
fective illness without a somatic diagnosis, the mean year of birth was 1949 (standard deviation [SD]⳱16), compared with 1941 (SD⳱13) for the somatically ill patients (t⳱5.28, P⬍0.001). For the patients with a paranoid disorder, the corresponding years were 1944 (SD⳱18) and 1952 (SD⳱12), respectively (t⳱4.94, P⬍ 0.001). The correlation between year of birth and number of different somatic diagnostic groups was significant for both groups for the affective patients: (r⳱ⳮ0.32, P⬍0.001) and for the paranoid patients (r⳱ⳮ0,40, P⬍0.001). The patients with affective psychosis received this diagnosis in 3,377 hospitalizations, 3,233 of which were established on a psychiatric ward and the rest on various somatic wards. Of the 3,233 hospitalizations on psychiatric wards, 78 patients (10.8 % of all patients diagnosed with affective psychosis) received 1 or more somatic diagnoses in 145 hospitalizations. The patients with paranoid psychosis received this diagnosis in 1,369 hospitalizations, 1,320 of which were on psychiatric wards. Forty-seven different paranoid patients (10.0 %) received a somatic diagnosis in a total of 83 of the 1,320 hospitalizations. The numbers of hospitalizations with somatic diagnoses was increased compared with that of the control subjects, both in the group composed of patients diagnosed with affective psychoses and the group diagnosed with paranoid disorders (Table 2). The numbers of hospitalizations were significantly increased in 11 out of 14 ICD groups among the affective patients. The exceptions were tumors, diseases of the musculoskeletal system, and diseases of the sense organs. For the paranoid group, the number of hospitalizations showed a significant increase in 10 of the 14 ICD groups. No differences between the case subjects and control subjects were found in the same diagnostic groups, as mentioned earlier, and neither in the group “other diseases.” Measured in absolute numbers, the affective disorder patients appeared 1,618 times in the 14 diagnostic groups, compared with 696 times for their control subjects. The figures for the patients with paranoid psychoses were 1,019 and 437 for their control 256
subjects. (For the calculations of the aforementioned numbers, every single patient could give rise to 1 diagnosis in each of the 14 different ICD groups.) In the paranoid group, when excluding the patients with substance abuse, the significant differences between the patients and control subjects disappeared for the groups of gastrointestinal and genitourinary diseases, thus resulting in an excess number of somatic hospitalizations in 8 of the 14 ICD groups. No differences were noted in the affective group between the patients who had been diagnosed with a substance abuse at least once and those who had not (Table 3). As there were 14 somatic diagnostic groups, each patient and control subject could theoretically be found in every group. However, this was not the case. The affective disorder patients appeared in 0–10 groups (first percentile⳱1, second percentile⳱2, third percentile⳱4) and their control subjects in 0–8 groups (percentiles 1, 2, and 3⳱ 0, 0, 1, respectively (Z⳱ⳮ13.1, P⬍0.001). For the paranoidpatients and control subjects, the figures were similar, with the same distribution in the groups (0–10 and 0–8, respectively). The percentiles 1–3 were as follows: 1, 5, 4 for the patients and 0, 0, 1 for control subjects (Z⳱ⳮ10.0, P⬍0.001). After the exclusion of the patients who had received a diagnosis of schizophrenia, 546 affective and 342 paranoid patients remained. The principal results presented in Table 2 were not changed. This was true for all the somatic ICD groups. An analysis was also performed for the “pure” psychiatric groups, that is, for the patients with no other psychiatric diagnoses registered apart from affective psychosis or paranoid disorder during the 15-year period (Table 4). In the former group (composed of 123 individuals), the patients had received at least 1 somatic diagnosis more often than the control subjects, but in the second group (n⳱84), no significant differences were observed between the patients and control subjects. DISCUSSION The patients with affective psychoses as well as those with paranoid disorders showed an inPSYCHOSOMATICS
Dalmau et al.
creased number of hospitalizations with somatic diagnoses compared with their matched control subjects. In principle, the two psychiatric diagTABLE 2.
noses correlated with the same groups of somatic diseases. Thus, the increase in somatic hospitalizations appeared in 11 and 10 of the 14
The probability of receiving somatic diagnoses for the patients with affective psychoses and paranoid disorders Affective Psychoses
Diseases (ICD-8/ICD-9) Infectious and parasitic diseases Neoplasm Endocrine diseases Diseases of the respiratory system Diseases of the circulatory system Diseases of the genitourinary system Diseases of the digestive system Diseases of the nervous system Diseases of the sense organs Diseases of the musculoskeletal system and connective tissue Diseases of the skin and subcutaneous tissue Injuries Symptoms. signs. and ill-defined conditions Other diseases
Paranoid Disorders
Odds Ratio
Confidence Interval
Odds Ratio
Confidence Interval
3.03 1.35 2.95 2.36 1.85 2.13 2.25 3.71 0.76
1.96–4.67 0.92–1.98 1.97–4.42 1.62–3.44 1.38–2.49 1.62–2.82 1.64–3.09 2.18–6.31 0.39–1.46
3.84 1.57 4.14 1.95 2.18 1.71 1.99 7.00 1.70
2.24–6.57 0.95–2.59 2.36–7.27 1.21–3.15 1.47–3.23 1.20–2.42 1.35–2.92 3.46–14.15 0.89–3.25
1.36 5.05 5.37 6.68 1.57
0.94–1.96 2.40–10.60 4.11–7.03 5.16–8.66 1.13–2.18
1.43 7.38 6.9 5.97 0.93
0.87–2.36 2.98–18.29 4.82–9.88 4.32–8.24 0.65–1.35
Note: Comparisons have been made with the matched control subjects and are expressed as odds ratios. Confidence intervals of 95% are used. ICD-8/ICD-9: International Classification of Diseases, 8th and 9th Editions. respectively.
TABLE 3.
The probability of receiving somatic diagnoses for patients with affective psychoses and paranoid disorders. who have had never had a diagnosis of substance abuse Affective Psychoses
Diseases (ICD-8/ICD-9) Infectious and parasitic diseases Neoplasm Endocrine diseases Diseases of the respiratory system Diseases of the circulatory system Diseases of the genito-urinary system Diseases of the digestive system Diseases of the nervous system Diseases of the sense organs Diseases of the musculoskeletal system and connective tissue Diseases of the skin and subcutaneous tissue Injuries Symptoms. signs. and ill-defined conditions Other diseases
Paranoid Disorders
Odds Ratio
Confidence Interval
Odds Ratio
Confidence Interval
2.14 1.25 2.72 1.88 1.72 2.09 1.89 3.50 0.78
1.31–3.50 0.84–1.84 1.78–4.16 1.24–2.85 1.26–2.36 1.54–2.85 1.33–2.68 1.89–6.50 0.40–1.56
2.42 1.56 4.28 1.78 1.87 1.34 1.53 8.14 1.57
1.29–4.55 0.89–2.72 2.21–8.31 1.01–3.14 1.20–2.92 0.90–2.01 0.97–2.40 3.32–19.99 0.65–3.83
1.34 4.31 3.85 5.76 1.56
0.88–2.04 1.88–9.85 2.87–5.18 4.34–7.65 1.08–2.24
1.26 5.55 5.21 4.86 0.78
0.69–2.28 1.83–16.85 3.36–8.09 3.34–7.07 0.51–1.21
Note: Comparisons have been made with matched control subjects and are expressed as odds ratios. Confidence intervals of 95% are used. ICD-8/ICD-9: International Classification of Diseases, 8th and 9th Editions. respectively.
VOLUME 39 • NUMBER 3
• MAY–JUNE 1998
257
Somatic Morbidity
groups, respectively. The results are fairly similar to those presented previously for patients with schizophrenia.9 The differences between the schizophrenic patients and the present two groups were that tumors were overrepresented among the schizophrenic patients but not among the affective or paranoid patients and that the frequency of genitourinary diseases was similar to that of the control subjects among the schizophrenic patients and greater among the affective and paranoid patients. Concerning tumors, most studies have concentrated on their frequency among schizophrenic patients. Earlier studies showed an underrepresentation of cancer deaths among schizophrenic patients,13,14 but it has been suggested that this is best explained by methodological problems.15,16 Later studies have presented results ranging from a slight excess mortality in cancer17–19 to a small undermortality.20–23 To our knowledge, no comparisons between the incidence of cancer morbidity and mortality have been made among schizophrenic patients and patients with affective psychoses. Ghadirian and Engelsmann24 found an increased rate of physical illness in manic-depressive patients compared with schizophrenic patients in all surveyed groups of diseases, except for the gastrointestinal diseases. However, their study design differed from ours in many reTABLE 4.
The probability of receiving somatic diagnoses for patients with affective psychoses and paranoid disorders but no other psychiatric diagnoses registered during the 15-year period Affective Psychoses
Paranoid Disorders
Control Control Patients Subjects Patients Subjects Somatic disease No somatic disease Total Odds ratio Confidence interval (95%)
258
78
58
52
47
45 123
65 123
32 84
37 84
1.94
1.28
1.17–3.23
0.69–2.37
spects. Their study population included only outpatients, and as register data was not used information was obtained from interviews and a review of patient records. In an investigation by Fink,25 focusing on the number of hospitalizations during an 8-year period in a Danish population, 74% of the patients once hospitalized on a psychiatric ward had at least 1 hospitalization on a somatic ward as well. In the general population, 41% had been hospitalized on a somatic ward. There was an increased risk of admission to a general ward for all psychiatric diagnoses, except for schizophrenia. One of the most persistent findings in the literature is an increased mortality/morbidity due to cardiovascular diseases among patients with affective disorders,26–29 and this finding is in accordance with ours. Some authors have also noted an increased rate of respiratory diseases among patients with affective psychoses.26,29 In 1982, Linda˚gerd30 studied hospitalizations for the “depressive spectrum” of the entire male population in Gothenburg, a Swedish city of about 500,000 citizens. The “spectrum” included both uni- and bipolar disorders, and he found an increased number of hospitalizations due to infections, myocardial infarction, and asthma. In this study, an overrepresentation of endocrine diseases was found among the patients with affective psychoses as well as among those with paranoid disorders. The possibility of a positive association between affective disorders and diabetes mellitus has been addressed in many studies. Such an association has been claimed to exist for depressive states31 as well as for bipolar disorders.32 In the latter case, the possibility that lithium may contribute to the diabetic condition has attracted much attention. In a review article, Russel and Johnson33 concluded that both the affective disorder in itself and lithium could lead to the development of diabetes mellitus. Little has been published about paranoid disorders and their relationship to somatic diseases. It is apparent that this subject has attracted very little attention and the literature is limited. In some studies many different psychoses are PSYCHOSOMATICS
Dalmau et al.
put together in a group of “functional psychoses,” in which paranoid conditions are generally included.34 One article that has dealt specifically with paranoid disorders is that of Jo¨rgensen and Mortensen,35 who investigated diagnostic stability over time. For patients admitted for the first time with functional psychoses, paranoia was one of the most unstable diagnoses; half of the patients were classified differently at the latest re-admission. Diagnostic instability may influence the results, and to evaluate its importance we have analyzed our material, excluding all patients who at any time have had another psychiatric diagnosis than paranoid disorder (Table 4). In contrast to the patients with affective psychosis, the results among the paranoid patients changed, and the differences noted between the patients and control subjects were no longer significant. This finding is difficult to explain, but one may speculate that the diagnosis paranoid disorder has been used quite loosely. Another possible explanation is the small size of the group of “pure” paranoid patients. Also, a difference in the numbers of somatic hospitalizations is seen between patients with a single diagnosis and patients with multiple diagnoses, which may reflect a difference in the severity of psychiatric disease in these two patient groups. It might be that the difference between mixed and pure groups would disappear if mono- and polydiagnostic patients with equal numbers of psychiatric admissions were compared. The reason for the increased number of somatic hospitalizations among the psychiatric patients is probably multifactorial in nature. The first important question to ask is whether or not it reflects a true excess in somatic morbidity. Another explanation for the hospitalizations could be somatization and a greater tendency to seek medical care. We have noted an excessnumber of diagnoses of “symptoms, signs, and illdefined conditions,” which may be dependent on treatment-seeking behavior. The patients were hospitalized because of a wide range of diagnoses, however, and as the threshold for admittance to the hospital normally is fairly high, the adoptance of hospital admissions as a measure of morbidity should result in a rather strict defVOLUME 39 • NUMBER 3
• MAY–JUNE 1998
inition of that term. Other interpretations of the reasons for hospitalizations due to different somatic diagnoses have been given, however. Fink36 compared the diagnostic pattern of medical admissions among psychiatric patients and the general population and concluded that the most likely explanation for the excess number of admissions in the former group was different illness behavior, and not a true increase in morbidity. Further, another explanation for the increased number of somatic hospitalizations among our patients could be the fact that the patients are already within the health care system, which could lead to the detection of more diseases and abnormalities than otherwise. When a patient is admitted to a psychiatric ward, a physical investigation and laboratory tests are undertaken to detect somatic diseases that could be related to the psychiatric illness or its deterioration. Patients who debut with psychotic conditions are usually given a computed tomography head scan, and an electroencephalogram is done as well. We have accepted somatic diagnoses as somatic and psychiatric diagnoses as psychiatric, irrespectively of whether the patient was being treated on a somatic or psychiatric ward when the diagnosis was made. This should prevent underdiagnosis of somatic diseases, for example, when a patient, because of practical or psychological reasons, is admitted to a psychiatric ward when in need of somatic investigation or treatment, or when the same patient during psychiatric care gets a somatic disease. On the other hand, a certain amount of overdiagnosis may be expected, for example, when the somatic disease would not have warranted admission to a somatic ward if the patient did not already have a psychiatric illness, or if a psychiatric patient happens to have a somatic disease that is noted as a subdiagnosis in the patient record. To give some indication of the possible extent of overdiagnosing we have looked at the total number of hospitalizations on psychiatric wards where one diagnosis was either affective psychosis or paranoid disorder, and the other somatic. For both groups, about 10% of the pa259
Somatic Morbidity
tients had received a somatic diagnosis when hospitalized on a psychiatric ward. In some cases, this disease may not per se have led to inpatient somatic care, and in other cases the opposite may be true. Our material does not allow us to estimate the proportions between these possibilities. However, it seems improbable that this factor has affected the main results presented in this study. The substance abuse disorders are known to be related to both psychiatric and somatic diseases.37,38 In our material, about 29% of the patients with paranoid disorders had a diagnosis of substance abuse. This contrasts with the 18% in the group with affective psychoses. This difference is hard to interpret, and we have not been able to find any relevant studies in the literature. The control group consists of persons without psychiatric diagnoses, which means that they, by definition, have no known substance abuse history. Therefore, we have separately analyzed the results for the patients with and without substance abuse. When excluding the former, we still found a significant difference between the patients and control subjects in most of the somatic ICD groups (Table 3). For the affective group, this procedure did not lead to any differences in the results. In the paranoid group, the number of groups with an excess number of hospitalizations with somatic diagnoses decreased from 10 to 8; the differences seen between the patients and control subjects in the groups of gastrointestinal and genitourinary diseases disappeared. Other important environmental factors related to somatic morbidity are smoking and diet. It is well known that patients with psychiatric disorders smoke more than others.39 It is also
possible that their dietary habits differ from persons without psychiatric disorders, thus increasing the risk of certain somatic diseases. It would have been interesting to analyze how these environmental factors, and also social factors, as for example, social isolation, unmarried status, and unemployment, were distributed among our patients and control subjects. However, in a register study of this type this is not possible. Suicides and suicide attempts are registered in the group of injuries. As suicide attempts may be a manifestation of psychiatric disease the results in this group might reflect psychiatric morbidity rather than somatic morbidity. A higher than expected incidence of atopic disorders has been discovered among patients with bipolar disorders.29,40 The same is also true for diabetes mellitus.32,33 This could indicate the presence of a common etiology, possibly of a genetic character. Genetic factors are known to play a role in the etiology of all these diseases.41–44 It has also been proposed that there is an inverse relationship between Down’s syndrome and bipolar affective disorders,45 which may also lead to speculations concerning genetic associations. This study has shown that patients diagnosed with affective and paranoid conditions show an increased number of hospitalizations with somatic diagnoses and that their somatic diagnostic pattern is the same as for schizophrenic patients. We find it reasonable to believe that this increase reflects an increase in somatic morbidity. There is a need for further investigations among patients with less severe psychiatric illnesses. Another intriguing question is that of whether somatic morbidity differs before and after the debut of a psychiatric illness.
References
1. Corten PH, Ribourdoille M, Hermann P, et al: Epidemiological survey of the “Natural” mortality in psychiatry. Acta Psychiatr Belg 1988; 88:349–371 2. Eastwood MR, Trevelyan MH: Relationship between physical and psychiatric disorder. Psychol Med 1972; 2:363–372 3. Murphy JM, Monson RR, Olivier DC, et al: Relations 260
over time between psychiatric and somatic disorders: the Stirling County Study. Am J Epidemiol 1992; 136:95–105 4. Koranyi EK: Morbidity and rate of undiagnosed physical illnesses in a psychiatric clinic population. Arch Gen Psychiatry 1979; 36:414–419 5. Shapiro S, Skinner EA, Kessler LG, et al: Utilization PSYCHOSOMATICS
Dalmau et al.
of health and mental health services.Arch Gen Psychiatry 1984; 41:971–978 6. Eastwood MR, Mindham RHS, Tennent TG: The physical status of psychiatric emergencies. Br J Psychiatry 1970; 116:545–550 7. Maricle RA, Hoffman WF, Bloom JD: The prevalence and significance of medical illness among chronically mentally ill outpatients. Community Mental Health Journal 1987; 23:81–90 8. Wells KB, Golding JM, Burnam MA: Chronic medical conditions in a sample of the general population with anxiety, affective and substance abuse disorders. Am J Psychiatry 1989; 146:1440–1445 9. Dalmau A, Bergman B, Brismar B: Somatic morbidity in schizophrenia—a case control study. Public Health 1997; 111:393–397 10. Patientregistret, 1987–1995. Kvalitet och inneha˚ll. Epidemiologiskt centrum, Socialstyrelsen Stockholm, 1997 11. Westerholm B (ed): Swedish version of International Classification of Diseases, Eighth Revision, 1982 12. Sandlund M-B (ed): Swedish version of International Classification of Diseases, Ninth Revision, 1986 13. Katz J, Kunofsky S, Patton RE, et al: Cancer mortality among patients in New York mental hospitals. Cancer 1967; 20:2194–2199 14. Rassidakis NC, Kelepouris M, Goulis K, et al: On the incidence of malignancy among schizophrenic patients. Agressologie 1973; 14:269–273 15. Fox BH: Cancer death risk in hospitalized mental patients. Science 1978; 201:966–968 16. Scheflen AE: Malignant tumors in the institutionalized psychotic population. AMA Archives of Neurology and Psychiatry 1951: 65:145–155 17. Nakane Y, Ohta Y: The example of linkage with a cancer register, in Psychiatric Case Registers in Public Health: A Worldwide Inventory 1960–1985, edited by ten Horn GH, Giel R , Gulbinat WH, Henderson JH, et al. Amsterdam, The Netherlands, Elsevier Science Publishers B.V., 1986, pp. 240–245 18. Craig TJ, Lin SP: Cancer and mental illness. Compr Psychiatry 1981; 22:404–410. 19. Allebeck P, Wistedt B: Mortality in schizophrenia. Arch Gen Psychiatry 1986; 43:650–653 20. Wood JB, Evenson RC, Cho DW, et al: Mortality variations among public mental health patients. Acta Psychiatr Scand 1985; 72:218–229 21. Brook OH: Mortality in the long-stay population of Dutch mental hospitals. Acta Psychiatr Scand 1985; 71:626–635 22. Giel R, Dijk S, van Weerden-Dijkstra JR: Mortality in the long-stay population of all Dutch mental hospitals. Acta Psychiatr Scand 1978; 57:361–368 23. Mortensen PB: The occurrence of cancer in first admitted schizophrenic patients. Schizophr Res 1994; 12:185–194 24. Ghadirian AM, Engelsmann F: Somatic illness in VOLUME 39 • NUMBER 3
• MAY–JUNE 1998
manic-depressive and schizophrenic patients. J Psychosom Res 1985; 29:281–286 25. Fink P: Psychiatric and somatic comorbidity: the general population’s utilization of hospital admissions (thesis). Institute of Basic Psychiatric Research, Department of Psychiatric Demography, Psychiatric Hospital, Aarhus, Denmark, 1992, ISBN 87–90017–46–3 26. Sharma R, Markar HR: Mortality in affective disorder. J Affect Disord 1994; 31:91–96 27. Weeke A, Juel K, Vaeth M: Cardiovascular death and manic-depressive psychosis. J Affect Disord 1987; 13:287–292 28. Murphy JM, Monson RR, Olivier DC: Affective disorders and mortality. Arch Gen Psychiatry 1987; 44:473–480 29. Baldwin JA: Schizophrenia and physical disease: a preliminary analysis of the data from the Oxford Record Linkage Study, in Biochemistry of Schizophrenia and Addiction, edited by Hemmings G. Lancaster, UK, MTP Press, 1980, pp. 297–318 30. Lindega˚rd B: Physical illness in severe depressives and psychiatric alcoholics in Gothenburg, Sweden. J Affect Disord 1982; 4:383–393 31. Gavard JA, Lustman PJ, Clouse RE: Prevalence of depression in adults with diabetes. Diabetes Care 1993; 16:1167–1178 32. Lilliker SL: Prevalence of diabetes in a manic-depressive population. Compr Psychiatry 1980; 21:270–275 33. Russel JD, Johnson GFS: Affective disorders, diabetes mellitus and lithium. Aust N Z J Psychiatry 1981; 15:349–353 34. Hewer W, Ro¨ssler W, Fatkenheuer B: Mortality among patients in psychiatric hospitals in Germany. Acta Psychiatr Scand 1995; 91:174–179 35. Jorgensen P, Mortensen PB: Admission pattern and diagnostic stability of patients with functional psychoses in Denmark during a two-year observation period. Acta Psychiatr Scand 1988; 78:361–365 36. Fink P: Physical disorders associated with mental illness: a register investigation. Psychol Med 1990; 20:829–834 37. Regier DA, Farmer ME, Rae DS, et al: Comorbidity of mental disorders with alcohol and other drug abuse. JAMA 1990; 264:2511–2518 38. Kissin B, Begleiter H (eds): The Biology of Alcoholism: Clinical Pathology, Vol 3. New York, Plenum, 1974 39. Glassman AH: Cigarette smoking: implications for psychiatric illness. Am J Psychiatry 1993; 150:546– 553 40. Nasr S, Altman EG, Meltzer HY: Concordance of atopic and affective disorders. J Affect Disord 1981; 3:291–296 41. Kendler KS, Pedersen NL, Neale MC, et al: A pilot Swedish twin study of affective illness including hospital- and population-ascertained subsamples: results of model fitting. Behav Gen 1995; 25:217–232 261
Somatic Morbidity
42. Goodwin FK, Jamison KR: Manic-Depressive Illness. New York, Oxford University Press, 1990, pp. 376– 401 43. Blumenthal MN, Amos DB: Genetic and immunologic basis of atopic responses. Chest 1987; 91(suppl): 176S–184S
262
44. Kingston HM: Genetics of common disorders. BMJ 1989; 298:949–952 45. Craddock N, Owen M: Is there an inverse relationship between Down’s syndrome and bipolar disorder? Literature review and genetic implications. J Intellect Disabil Res 1994; 38:613–620
PSYCHOSOMATICS