Prevalence of chronic pain in psychiatric patients

231

Pain, 29 (1987) 231-237 Elsevier

PAI 01041

Prevalence of chronic pain in psychiatric patients Santosh K. Chaturvedi Department

ofPsychiatry,National Institute ofMental Health

and Neurosciences,

Bangalore 29, Karnataka (India) (Received

16 June 1986, revised received 20 October

1986, accepted

28 October

1986)

Five hundred consecutive patients attending a psychiatric clinic were examined in order Summary to ascertain the prevalence of chronic pain in various psychiatric illnesses and demographic categories. Chronic pain was found to be a frequent symptom in anxiety neurosis (60%), neurotic depression (45%) and hysteria (24.3%). Less than 3% of psychotic patients reported chronic pain. Females and those patients who had entered further education beyond secondary level were found to have significantly higher (P < 0.001) representation as compared to the psychiatric population without pain. The results are in accordance with certain earlier studies carried out almost two decades ago. Chronic pain was found to be a common symptom of psychiatric illness, reported by 18.6% patients, especially those diagnosed as having neurosis. It was also reported more often by females and by those with a higher education. The reasons for these observations require investigation.

Key words: Chronic

pain;

Psychiatric

illness

Introduction

Many studies have described various psychiatric illnesses in patients suffering from chronic pain [2,4,13,15,23,25,26], but few have attempted to determine the frequency or magnitude of chronic pain as a symptom in psychiatric disorders, with the exception of depression. Numerous studies have reported pain and other somatic complaints in depressive patients [3,5,12,13,18,20,24,28]. Only a few investigations [4,15,26,27] have focussed on studying chronic pain as a presenting feature Correspondence to: SK. Chaturvedi, M.D., Dept. of Psychiatry, and Neurosciences, Bangalore 29, Kamataka, India.

0304-3959/87/$03.50

0 1987 Elsevier Science Publishers

National

B.V. (Biomedical

Institute

Division)

of Mental

Health

232

in a psychiatric population. Pain, either short-lasting or chronic, has been reported as quite a common symptom in patients suffering from psychological illnesses such as depression, hypochondriasis and hysteria [1.7,9,19,27]. In psychotic patients. especially those with schizophrenia, a very infrequent association with pain has been observed [6.11,16,24,26,27]; and when present, it is either bizarre or acquires a delusional quality and only occurs very rarely as a presenting complaint [6,26]. This study has been carried out to ascertain the prevalence of chronic pain in different psychiatric illnesses presenting in a psychiatric outpatient department in India. Chronic pain is currently recognised as a significant cause of morbidity and suffering as well as of economic loss due to disability, unemployment and overutilisation of health care systems [6]. The problem is further compounded by the poor compliance of pain patients with psychiatric treatment. Treatment. is either not properly followed or rejected by many patients [6,8]. Stengel [24] had reported pain as a presenting symptom in 45560% of cases in psychiatric clinics. With growing interest in the issues regarding psychiatric aspects and the role of psychological management of chronic pain, it is important to identify the magnitude of chronic pain in different psychiatric illnesses, as well as in different demographic categories of patients presenting to a psychiatric clinic. Most previous studies have offered little in the way of conclusive empirical evidence, largely due to shortcomings of research methodology including inadequate or biassed sampling methods, poor specification of diagnostic criteria for inclusion in groups, and inadequate procedures for establishing reliability of diagnostic classifications. The present study has attempted to overcome or minimise these limitations.

Methods Five hundred consecutive patients, aged between 16 and 55 years, were examined and cases fulfilling the criteria for chronic pain were identified. If patients - either voluntarily or on interrogation - reported pain as a chief complaint, occurring daily or once every 2 days for a period of more than 6 months without any related or unrelated organic pathology, they were identified as ‘chronic pain patients.’ Information was collected from reliable relatives or friends of the subject, and detailed mental state evaluations and physical examination were carried out in all cases. Laboratory investigations were conducted if necessary. The diagnosis was arrived at in consultation with a consultant psychiatrist and presented in accordance with the International Classification of Diseases, 9th revision [30]. Cases, in whom diagnosis could not be ascertained with conviction, were not included. Similarly, cases with a suspected physical or organic disorder were also not included. Socio-demographic details and clinical diagnosis were recorded on a data collection proforma. Diagnosis was arrived at after detailed evaluation of the patient and mutual concurrence of a minimum of two psychiatrists, at least one of whom was a consultant psychiatrist. Rates of chronic pain per 100 patients were computed for psychiatric illnesses, as well as for different demographic categories.

233

Results

The prevalence of chronic pain according to demographic category (Table I) indicated comparable rates as far as age, habitat and marital status were concerned. In all, 93 out of 500 psychiatric patients presented with chronic pain as a predominant symptom (i.e., a rate of 186/1000 population). On direct interrogation, another 41 patients reported pain, but these did not meet the study criteria for chronic pain. In these 41 cases, the pain lasted less than 6 months and occurred l-2 times/week. Twenty of these 41 cases also had identifiable physical illnesses. The duration of the patients’ pain problems ranged from 8 months to 12 years (average 3.84 years): between 1 and 2 years in 358, 2 and 5 years in 318, 5 and 10 years in 17% and more than 10 years in 7%. The duration of psychiatric illness in the chronic pain patients was between 1 and 5 years in the majority (70%) of cases. Eight pain patients reported that the pain problem preceded other psychiatric

TABLE

I

SOCIO-DEMOGRAPHIC DISTRIBUTION CHRONIC PAIN (N = 500)

years years years years

16-25 26-35 36-45 46-55 sex

OF

PSYCHIATRIC

PATIENTS

AND

N

Patients with chronic pain

Rate of chronic pain/100 cases

207 140 80 73

44 24 15 10

21.2 17.1 18.8 13.7

315 185

37 56

11.7 30.3

287 111

24 29

8.4 26.1

102

40

39.2

243 257

49 44

20.2 17.1

207 193

36 57

17.4 19.5

RATE

OF

*

Male Female Educaiion * Below secondary level Secondary level Beyond secondary level Background Rural Urban Marital stam Unmarried Married

* When patients with and without chronic pain are compared, a highly significant difference (P < 0.001) is found with regard to sex and education. No significant difference was observed for age, background or marital status.

234 TABLE

II

PREVALENCE Psychiatric

OF CHRONIC

illness

PAIN IN PSYCHIATRIC N

DISORDERS

Patients with chronic pain

Rate of chronic pain/100 case5

Schizophrenia Affective psychosis Depression Mania Anxiety states Depressive neurosis Hysteria Other neurosis Drug dependence Others

110

62 40 100 37 15 27 84

4 0 24 45 9 4 0 5

16.0 0.0 60.0 45.0 24.3 26.7 0.0 5.9

Total sample

500

93

18.6

25

._.-____

1.X

features; in 20 cases, psychiatric symptoms had preceded the pain problem. In others, it was not possible to distinguish whether pain or psychiatric symptoms appeared first. Percentage distribution of chronic pain in psychiatric illnesses is presented in Table II. Of the 93 cases (18.6%) who fulfilled the criteria, chronic pain was noted to be a presenting complaint most frequently in neurotic disorders. 60% of anxiety neurosis, 45% of depressive neurosis and 24.3% of hysterical neurosis patients reported chronic pain. Less than 3% of psychotic patients reported chronic pain as a presenting feature. However, 16% of psychotic depressives complained of chronic pain. None of the manics or drug dependence patients reported chronic pain. On examining the socio-demographic data and comparing this with psychiatric patients without pain as a presenting complaint, one can state that significantly more females (P -C0.001) and those with higher education ( P < 0.001) report chronic pain. About 30% of female patients attending the outpatient clinic complained of pain, compared to only 11% of males. Similarly, about 39% of those with higher education, and only 8% of those less educated reported chronic pain. One age group. of those also finds over-representation of females, of the younger educated beyond secondary level. and of married subjects in the pain sample.

Discussion This study attempts to address an important area, namely, the prevalence of chronic pain in psychiatric patients. Pain is considered to be a common symptom in both medical as well as psychiatric clinics. The limitations encountered by previous studies were overcome by using strict inclusion and exclusion criteria. Consecutive selection of cases who met the criteria for chronic pain rules out any selection bias.

235

Clinical psychiatric diagnosis was also ascribed carefully and by mutual concurrence. Cases who had doubtful organicity or problems regarding psychiatric diagnosis were excluded, to ensure clinically distinct groups. It is important to know about the magnitude of the problem of chronic pain in psychiatric patients, if the subject is suffering from frequently occurring pain over a period of months or even years without much relief. Such cases probably visit one clinic after another, in vain. Most researchers have agreed that chronic pain is more relevant to psychiatric practice. Unfortunately, most studies have not focussed on prevalence of chronic pain in psychiatric patients and psychiatric illness, with the exception of depressive illness. However, many studies quoted earlier, do mention psychiatric illness in chronic pain patients. Similar reports from this centre [6,7] have also highlighted psychiatric problems in pain patients. The prevalence (18.6%) in psychiatric out-patients is markedly low compared to other reports on pain in psychiatric out-patients and primary care psychiatric populations [9-11,22,23,29]. The difference is understandable as most of these previous studies have considered simply a pain complaint, probably of any duration, rather than chronic pain (of duration longer than 6 months) as in this study. The patients in the current study who only reported pain incidentally, did not meet the criteria laid down for inclusion, otherwise the prevalence rate might have been higher, as found by Spear [23]. In another retrospective study [7], the prevalence of chronic pain was found to be 14%, slightly lower than the rate in the present study. Chronic pain appears to be a very common symptom among patients with anxiety states (60%); 45% of patients with neurotic depression had chronic pain, whereas only a quarter (24.3%) of those with hysteria reported chronic pain. Chronic pain is evidently not a presenting feature in psychotic patients. In depressive psychosis, however, chronic pain was reported in 16% cases. Klee et al. [II] surprisingly found that many backache patients in their series had various types of schizophrenia. However, anxiety neurosis was their commonest diagnosis. Also, the rate of pain in anxiety neurosis (64%) found by Klee et al. [ll] is comparable to present results. Results reported by Spear [22,23] were similar in terms of pain being relatively more frequent in the anxiety/hysterical group of patients. Merskey [15] studied persistent pain, i.e., pain of more than 3 months’ duration, as a major presenting complaint, a criterion similar to that used in the present study. He compared persistent pain patients with patients without pain and found a preponderance of neurotic conditions - particularly hysteria - amongst those with pain. The finding that female patients and those with higher education present with chronic pain significantly more often has already been observed by other researchers [2-5,13,23-251. There is no sound explanation offered for this predilection of the pain problem in female patients. Similarly, it is difficult to offer reasons for over-representation in the educated group of patients. Further research is required to establish biological and psychological factors which might explain these findings. The findings of the present study support the contention of various other studies that pain is a common symptom in psychiatric patients and merits more attention than it usually receives. Also, this study suggests that future studies should con-

236

centrate on chronic

pain, and the use of well-defined diagnostic criteria. its proposed by Tupin and Abramowitz [25]. The report also indirectly indicates that no appreciable difference seems to exist in the presentation of chronic pain in psychiatric illness in India compared with the U.S.A., U.K. and Canada over last 2 or 3 decades, since the results largely conform with those of Merskey [15]. Klee et al. [ll], Walters [27] and Spear [22]. However. the rates found by most of these studies were higher than those in the present study. Possible reasons for this discrepancy have already been described in terms 01 differences in methodology, sample selection and diagnostic criteria. Information regarding the magnitude of a chronic pain problem in a psychiatric clinic can be very important in planning effective management for these patients. Wherever necessary, pain clinics might be useful in handling such cases. There is poor acceptance of psychiatric treatment by pain patients. and many treatment strategies face high drop-out rates with these patients [8,13.14]. Being aware of this problem, effective therapy must be considered very cautiously. In this investigation, it was difficult to study the relationship of drug treatment to the presence or absence of pain in the psychiatric groups. In the case of most patients. it was their first visit to the psychiatric clinic, and no attempt at follow-up was made. The relationship of drug treatment to the presence or absence of pain in the psychiatric groups could provide additional information. which might be of help in planning effective management of pain patients. References 1 Agamal. A.K., Kumar. R. and Kapoor. R.N., Somatic symptoms of neurosis-index of body image, Indian J. Psychiat.. 15 (1973) 367-374. 2 Baker, J.W. and Merskey, H.. Pain in general practice, J. psychosom. Res.. 10 (1967) 383-390. 3 Blumer, D. and Heilbronn, M.. Chronic pain as a variant of depressive disease, J. new. ment. Dis., 170 (1982) 381-406. 4 Chaturvedi, SK.. Varma, V.K. and Malhotra. A.. Non-organic chronic intractable pain: a comparative study, Pain. 19 (1984) 87-94. 5 Chaturvedi. S.K., Varma, V.K. and Malhotra. A., Depressive symptoms in non-organic chronic pain. NIMHANS J., 3 (1985) 121-128. 6 Chaturvedi, SK. and Michael, A., Chronic pain patients m a psychiatric hospital. NIMHANS J.. 4 (1986) 19-24. 7 Chaturvedi. SK. and Michael, A.. Chronic pain in a psychiatric clinic, J. psychosom. Res.. 30 (1986) 347-352. 8 Chaturvedi, SK.. Current therapeutic trends in management of psychogenic chronic pain. In: K.N. Sharma and U. Nayyar (Bds.), Current Trends in Pain Research and Therapy, Vol. 1. Indian Sot. for Pain Res. and Ther., New Delhi, 1985, pp. 161-167. 9 Katon, W., Kleinman, A. and Rosen, G., Depression and somatization: a review. II. Amer. J. Med.. 72 (1982) 241-247. 10 Katon, W., Ries, R.K. and Kleinman, A., The prevalence of somatisation in primary care, Camp. Psychiat.. 2 (1984) 208-215. 11 Klee, G.D., Ozelis, S., Greenberg. 1. and Gallant, L.J.. Pain and other somatic complaints in a psychiatric clinic, Maryland St, med. J., 8 (1959) 188-194. 12 Knowing, L. von, Perris, C., Eisemann, M., Eriksson, U. and Perris, H., Pain as a symptom m depressive disorders. I. Relationship to diagnostic sub-group and depressive symptomatology. Pain. 15 (1983) 19-26.

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