Prevalence, symptom profile, and aetiology of depression in dementia sufferers

Journal ofAffectir,e Disorders, 29 (1993) 1-6 0 1993 Elsevier Science Publishers B.V. All rights reserved

0165-0327/S3/$OS.O0

JAD 01017

Prevalence,

symptom profile, and aetiology in dementia sufferers

C.G. Ballard,

G. Cassidy, C. Bannister

of depression

and R.N.C. Mohan

Unil~ersityDepartment of Psychiatry, Queen Elizabeth Psychiatric Hospital, Birmingham, UK (Received 18 November 1993) (Revision received 5 April 1993) (Accepted 21 April 1993)

Summary Ninety-two consecutive attenders at a day hospital for the assessment of dementia were assessed using the CAMDEX schedule. The prevalence of depression in the 58 dementia sufferers who fulfilled the entry criteria for the study was 24.1%. The prevalence of depression was similar in patients with senile dementia of Alzheimer’s type and those with vascular dementia. Patients with minimal dementia were significantly more likely to suffer from depression than those with mild or moderate dementia but there was no significant association with insight. The symptom profile of patients with minimal dementia was significantly correlated to that of patients with mild dementia and both were similar to the symptom profiles previously described amongst the elderly with functional depression. Physical illness was not associated with depression in the current sample. The implications of the findings are discussed.

Key words:

Dementia;

Depression;

Prevalence;

Symptom;

Introduction There has been great disparity between different studies in the reported prevalence of depression amongst patients with Alzheimer’s disease (Wragg and Jeste, 1989) although most authors

Correspondence to: Dr. C.G. Ballard, Lecturer in Psychiatry, University Department of Psychiatry, Queen Elizabeth Psychiatric Hospital, Mindelsohn Way, Birmingham B1.5 2 QZ, UK.

Physical

illness

have found the prevalence of depression to be between 15 and 30% (Lopez et al., 1990; Lazarus et al., 1987; Reifler et al., 1982; Reding et al., 1985; Teri and Wagner, 1991; Rovner et al., 1989). Less work has been undertaken to study depression in vascular dementia (VD). Cummmings et al. (1987) has given a specific prevalence estimate for cases of depression finding 4 out of 15 patients with VD to have a concurrent depressive illness. Similarly Erkinjuntti (1987) estimated that 28% of patients with VD suffered from depression.

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The symptom profile of depression in dementia sufferers has not been well delineated. Merriam et al. (1988) have suggested that dementia patients have less intrapsychic symptoms of depression and have prominent mood reactivity. Greenwald et al. (1989) compared the symptoms of 10 dementia patients with concurrent depression to 33 depressed patients without dementia finding boredom, initial insomnia, early morning wakening and delusions to be less common in those with both disorders. The work so far has hence utilised small samples and had not compared symptoms in those with dementias of differing types or severity. The aetiology of depression in dementia sufferers has also received little attention. Rovner et al. (1989) and Pearlson et al. (1990) found an increased family history of affective illness in dementia patients with depression, suggesting a familial or genetic element. Few other factors have been examined. Two obvious variables to study would be the relationship to physical illness and whether mood abnormality is related to the retention of insight into the dementia process. The former is particularly important in view of the strong association between physical illness and depression in the elderly with functional affective disorder (Burvill et al., 1989; Philpot et al., 1990). Service context The day hospital serves the City of Coventry, a deprived industrial City in the West Midlands of England. Referrals to the service with a probable diagnosis of dementia following a domiciliary assessment by a consultant old age psychiatrist are referred for a 4 week assessment either in the day hospital or an inpatient assessment facility. There are no strictly defined criteria determining whether patients are referred to day or inpatient assessment, the characteristics of the patients in the two settings are however described in more detail elsewhere (Handy et al., 1991); both units have a predominance of patients with dementia of mild to moderate severity although those allocated to day assessment have less behavioural problems and are less likely to have family carers (Handy et al., 1991).

Method Ninety two consecutive referrals to the day hospital assessment facility were prospectively assessed using the CAMDEX and CAMCOG schedules (Roth et al., 1986, 1988) and their carers interviewed using the informant section. The only items relevant to depression in the informant section of the schedule are those pertaining to loss of interest, guilt and sleep difficulties. The observer section includes an opportunity for the interviewer to judge whether the subject appeared obviously depressed. The patient section of the schedule includes the items described above for the informant schedule in addition to other questions concerning appetite, weight loss, concentration, indecisiveness, psychomotor retardation, social withdrawal and irritability. A previous analysis on the same sample (Ballard, 1991) compared patient with informant answers for a subset of the sample. Patients who had first degree relatives in contact more than once a week, where the informants ratings corroborated closely with those recorded by staff were utilised. The data collected suggested that patients often gave negative answers when symptoms were present, particularly for mood items. When positive responses were given by the patient for mood items these were likely to correlate closely with the informants response. Based upon these findings it was felt appropriate to include symptoms as present if they were recorded positively either during the patient interview, the informant interview or observed. The criteria for depression in appendix C of the CAMDEX schedule were then applied to these symptoms. If a patient fulfilled the criteria for a depressive disorder but was hierarchically diagnosed as having dementia, a diagnosis of modified depressive disorder was made. The dementia diagnosis and the severity of dementia were also assessed using the criteria in appendix C of the CAMDEX schedule. The criteria for depression are shown in appendix 1. Only patients who scored 2 out of 3 on the initial CAMDEX questions, hence qualifying to complete the patient section of the interview; and had a first degree relative in contact more than once a week were included for analysis.

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The history and examination parts of the schedule were used to determine the presence of physical illness. The authors considered each of the conditions recorded in order to decide whether they were severely disabling, life threatening or required specialist intervention by hospital practitioners. This judgement was made by consensus blind to the CAMDEX diagnosis. The presence of a physical illness judged to fulfil one of these categories was examined as a potentially important aetiological factor for depression in dementia sufferers. Insight was rated from question 58 of the CAMDEX schedule which asks whether the patients have difficulties with their memory. All patients with a diagnosis of dementia who did not consider themselves to have memory problems were judged to have lost insight. The individual symptom profiles of those patients with depression and dementia were obtained from the patient, observation and informant section of the schedules and were also used to compare the symptom profiles between those with different types and severity of dementia. Results The average age of the patients was 76.6 years, 60 were male and 32 female. Eighty seven patients had a primary diagnosis of dementia, 58 of whom fulfilled the selection criteria for inclusion in the study. Of these 40 patients fulfilled the CAMDEX criteria for the diagnosis of senile dementia of Alzheimer’s type (SDAT), 9 fulfilled the criteria for VD, 5 fulfilled the criteria for both VD and SDAT and a further 4 patients fulfilled the criteria for secondary dementia. Eight of the 40 patients with SDAT, 2 of the 9 patients with VD, 1 of the 5 patients with both disorders and 3 of the 4 patients with secondary dementia fulfilled the criteria for modified depressive disorder. In the statistical comparisons those with VD and those with both VD and SDAT were considered together in view of the poor reliability of distinguishing the 2 syndromes (Erkinjuntti, 1987). The prevalence rate of depression did not differ significantly between the different dementias (VD or VD + SDAT > SDAT, Fisher’s Exact Test P = 0.29, NS). Sec-

ondary dementias were not included in the statistical analysis in view of the small number of patients in this group. Severity of dementia Seven of the 15 patients with minimal dementia, 5 of the 27 with mild dementia and 2 of the 16 with moderate dementia fulfilled the study criteria for modified depressive disorder. Those with minimal dementia were significantly more likely to be depressed than those with dementia of mild (Fisher’s Exact Test P = 0.047”) or moderate (Fisher’s Exact Test P = 0.038*) severity. There was no significant difference in the prevalence of depression between those with mild and moderate dementia (Fisher’s Exact Test P = 0.30, NS). Insight Eleven of the 14 patients with modified depressive disorder retained insight into their memory loss compared to 29 of the 44 without depression, a nonsignificant difference (Odds Ratio (OR) 1.90, 95% confidence intervals (CI) 0.46, 7.86). Physical

illness

Twenty-five of the 58 patients had one or more physical illness which was considered to be life threatening, severely disabling or needed specialist medical treatment. These conditions are illustrated in Table 1. More than 25 conditions are listed as some patients had more than one medical problem. Seven of the 14 patients with modi-

TABLE

1

Physical

illness in the sample

Parkinson’s disease Cerebro vascular disease Diabetes Chronic obstructive airways Carcinoma Hypothyroidism Osteorthritis Partially sighted

disease

7 8 3 2 2 2 4

1

TABLE

2

The most common CAMDEX mood symptoms in patients with depression and minimal or mild dementia (n = 12) Symptom

No. of patients

%

(1) Depressed mood Loss of interest

12 12

100 100

(3) Loss of confidence more tense than usual

I1 11

91.7 91.7

(5) Loss of energy

IO

83.3

(6) More difficult to make decisions slowing of thoughts (8) Restless

during

9

75 75

the night

66.7

(9) Wake early talk slower than usual mood reactivity pessimism regrading future suicidal thoughts

58.3 58.3 5x.3 58.3 58.3

compared to those with mild dementia was + 0.53, a significant positive correlation at the 5% level. As there were only 2 patients with moderate dementia, correlations were not undertaken for this group. It was notable that neither of the patients had early morning wakening, diurnal mood variation or guilt. There were also significantly positive Spearman’s correlation coefficients to the 5% level for the symptom profiles of those with depression in the context of different types of dementia (SDAT vs. VD and both RS = +0.55, SDAT vs. secondary dementia RS = +0.55, VD and both vs. secondary dementia RS = +0.74). Discussion

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(14) Increased irritability felt anxious or frightened autonomic anxiety

50 50 50

(17) Difficulty falling asleep loss of weight

33.3 33.3

(19) Loss of appetite guilt feelings

25 25

fied depressive disorder had at least one physical illness compared to 18 of the 43 without, a nonsignificant difference (OR-1.39, 95% CI 0.22, 2.44). Symptoms The definition of modified depressive disorder required the presence of depressed mood and loss of interest hence these symptoms were present in every patient. The other common symptoms included loss of confidence, loss of energy, loss of concentration, difficulty making decisions, psychomotor retardation and tension. The most prevalent symptoms in those with minimal or mild dementia are shown in Table 2. The Spearman’s correlation coefficient for the symptom profiles of those with minimal dementia

The diagnoses of depression and dementia were made according to a reliable structured interview schedule using operationalised criteria. The CAMDEX schedule has been shown to have good inter-rater reliability for the diagnosis of dementia (Roth et al., 1986). However, it must be borne in mind that using the CAMDEX criteria to diagnose depression in the presence of dementia needed a novel approach which ignored the hierarchical structure of the CAMDEX diagnostic system. The study also amalgamated information from 3 sources in order to make the diagnosis, a different style of symptom collection based upon a previous analysis of the current sample (Ballard, 1991). This approach has not been subjected to validation studies. Only 58 of the 92 patients were included in the analysis. Although biasing the sample to some degree this was necessary in order to maximise the validity of the informants information. The sample is also somewhat atypical in its gender constitution, with an excess of males. There is no obvious explanation for this anomaly. The prevalence of modified depressive disorder was approximately 20% in patients with SDAT, those with VD and those with both disorders, these prevalence figures were in line with the majority of estimates from the previous literature (SDAT-Rovner et al., 1989 - 17%, Lopez et al., 1990 - 16.1%, Lazarus et al., 1987 - 20%, Reifler et al., 1982 - 22%, Reding et al., 1985 20%, VD-Cummings et al., 1987 - 26.7%); and

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suggests that there is little difference in the prevalence of depression between VD and SDAT. In a sample of patients over the age of 60 with functional depression Blazer et al. (1987) found sleep problems to be present in 94.7%. Early morning wakening was present in 84% of the subjects, psychomotor retardation in 84%, lethargy in 79%, decreased appetite in 73.7%, guilt in 73.7%, and suicidal thoughts in 47.5%. As can be seen, the prevalence of each of these facets except guilt is very similar to the current data set. Reiches et al. (1990) studied a mixed aged population finding guilt to be present in 32% of the over 70s with functional depression. This is more similar to the prevalence of guilt in the present study. One could hence hypothesise that the decreased prevalence of guilt was an age effect rather than a dementia effect. Previous authors have suggested that guilt and other psychological symptoms of depression are less common in dementia sufferers (Merriam et al., 1988). These symptoms appear to be common in those with minimal and mild dementia, although it is possible that they may be less common in those with dementia of greater severity. There is some support for this latter suggestion as neither of the 2 patients with dementia of moderate severity had guilt feelings, although 1 of them did experience feelings of hopelessness. The findings of Greenwald et al. (1989) that dementia patients with depression had less sleep problems than patients with functional depression was not upheld by the current study. Sleep disturbances were common in the present sample. However, it is possible that changes are limited to those with more severe dementia. Merriam et al., (1988) was struck by the marked mood reactivity amongst depressed patients with dementia. Mood reactivity was common in the current sample, although had a similar prevalence to that found by Blazer et al. (1987) in the elderly with functional depression. It therefore seems that depressed patients with minimal and mild dementias experienced depression in a similar way to those with functional depression. More work is, however, needed to look at those with more severe dementias. It is also interesting that the symptom profiles of depression in different types of dementias are very similar.

Physical illness was not associated with depression in dementia sufferers, this suggests a possible fundamental difference from the aetiology of functional depression in the elderly (Philpot et al., 1990; Burvill et al., 1989). The current patient sample came from a psychiatric day hospital setting who may be a group of patients with an artificially low level of physical illness because of referral bias. Despite this it is a potentially important finding in need of confirmation. Insight was not found to be significantly associated with depression in the current study, although patients with retention of insight were almost twice as likely to be depressed. Retention of insight is perhaps worthy of further investigation in a larger sample. Appendix illness

1. Criteria

for diagnosis

of depressive

Features 1 and 2 must be present for a diagnosis of depressice illness. 1. Depression of mood (feelings of sadness, gloom, hopelessness) described by patient or inferred by others from patient’s speech, facial expression and general behaviour. 2. Loss of pleasure and interest in most activities and pastimes. In addition, 4 of the following features should be present: 3. Loss of self-esteem and confidence. 4. Sustained fatigue, Loss of drive, energy. 5. Remorse over minor or imaginary misdeeds and mistakes in the past. 6. Groundless or disproportionate pessimism about the future. 7. Marked decrease in effectiveness and productivity at work and/or at home (observable by others). 8. Loss of libido after relatively normal functioning for age. 9. Social withdrawal, self-isolation. 10. Frequent attacks of tearfulness and crying. 11. Marked weight loss (when not dieting) or marked decrease in appetite. (More rarely increase in weight and appetite). 12. Insomnia nearly every night (more rarely hypersomnia).

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13. Sustained impairment in ability to think, concentrate or make decisions. 14. Feelings of worthlessness or guilt or remorse (nearly every day) without objective foundation. 15. Recurrent ideas about suicide and centring on potentially dangerous or lethal forms of self injury. 16. Depression at peak intensity in mornings. 17. Early morning awakening (2 or more hours before normal time). 18. Marked psychomotor retardation or agitation (manifest at clinical examination or observed by others). 19. Stable and effective personality prior to and between attacks of illness. 20. One or more previous attacks of depression followed by complete recovery or good remission. 21. Good response to somatic antidepressant treatment (tricyclic compounds, MAOI’s or ECT) in previous attacks. 22. Delusions of guilt or of serious or incurable physical disease. 23. Delusions of persecution, punishment or deserved retribution. 24. Auditory hallucinations (more rarely visual) with depressive content. Exclusion

criteria

A. Not associated with psychiatric features of an organic nature (clouding/delirium, consistent memory impairment, dementia). B. Not associated with symptoms diagnostic of a schizophrenic or paranoid psychosis. Notes (a) If the criteria for depression are satisfied, the presence of 4 features in items 15-21 in addition to 1 and 2 qualify for a diagnosis of endogenous depression. (b) If the criteria for depression are satisfied and 1 feature in items 22-24 is present, a diagnosis of psychotic depression is warranted. References Ballard, C.G., Chithiramohan, R.N., Handy, S. et al. (1991) Information reliability in dementia sufferers. Int. J. Geriat. Psychiat. 6, 313-316. Blazer, D., Bachar, J.R. and Hughes, D.C. (19871 Major

depression with melancholia: a comparison of middle age and elderly adults. .I. Am. Geriat. Sot. 35, 927-932. Butvill, P., Hall, W., Stampfer, H. et al. (1989) A comparison of early and late onset depressive illness in the elderly. Br. J. Psychiatry 155, 673-679. Cummings. J.L., Miller, B., Hill, M.A. et al. (19871 Neuropsychiatric aspects of multi infarct dementia of the Alzheimer’s type. Arch. Neurol. 44, 389-393. Erkinjuntti, T. (1987) Types of Multi infarct dementia. Acta Neurol. Stand. 75, 391-399. Greenwald, B., Ginsberg, E., Marin, D. et al. (1989) Dementia with co-existing major depression. Am. J. Psychiat. 146, 1472-1478. Handy, S., Chithiramohan, R.N., Ballard, C.G. et al. (1991) The rationale of patients allocation for psychogeriatric assessment. Int. J. Geriat. Psychiat. 6, 249-252. Lazarus, L.W., Newton, N., Cohler, B. et al. (19871 Frequency and presentation of depressive symptoms in patients with primary degenerative dementia. Am. J. Psychiat. 144, 4145 Lopez, O.L., Boiler, F., Becker, J.T. et al. (1990) Alzheimer’s disease and depression: neuropsychological impairment and progression of the illness. Am. J. Psychiat. 147, 855860 Merriam, A.E., Aronson, M.K., Gatson. P. et al. (1988) The psychiatric symptoms of Alzheimer’s disease. J. Am. Geriat. Sot. 36, 7-12 Pearlson, G.D., Ross, C.A., Lohr, W.D. et al. (1990) Association between family history of affective disorder and the depressive syndrome of Alzheimer’s disease. Am. J. Psychiatry 147, 452-456 Philpot, M. (1990) Affective disorders and physical illness in old age. Int. Clin. Psycho. Pharmacol. 5, (Suppl. 31, 7-20. Reding, M., Haycox, J. and Blass, J. (1985) Depression in patients referred to a dementia clinic: a 3 year prospective study. Arch. Neurol. 42,894-896 Reiches, F.M., Spiess, P.V. and Stieglitz, R.D (19901 The symptom pattern variations of unipolar depression during life span: a cross sectional study. Comp. Psychiatry 31, 457-464. Reifler, B.V., Larson, E. and Hanley, R. (19821 Coexistence of cognitive impairment and depression in geriatric outpatients. Am. J. Psychiat. 139, 623-626 Roth, M., Tym, E., Mountjoy, C. et al. (1986) CAMDEX: a standardised instrument for the diagnosis of mental disorder in the elderly with special reference to the early detection dementia. Br. J. Psychiat. 149, 698-709 Roth, M., Huppert, F., Tym, E. et al. (19881 CAMDEX: the Cambridge Examination for mental disorders in the elderly. Cambridge: Cambridge University Press. Rovner, B.W., Broadhead, J. Cote, L. Rosenstein, R. and Folstein, M.F. (1989) Depression and Alzheimer’s disease. Am. J. Psychiatry 146, 350-353 Teri, L. and Wagner, A.W. (1991) Assessment of depression in patients with Alzheimer’s disease: Concordance among informants. Psychol. Ageing. 6, 280-285. Wragg, R.E. and Jeste, D.V. (1989) Overview of depression and psychosis in Alzheimer’s disease. Am. J. Psychiat. 146, 577-587.