Mohammed T. Abou-Saleh

Principles and Practice of Geriatric Psychiatry.Editors: Professor John R. M. Copeland, Dr Mohammed T. Abou-Saleh and Professor Dan G. BlazerCopyright & 2002 John Wiley & Sons LtdPrint ISBN 0-471-98197-4 Online ISBN 0-470-84641-075aPhysical Illness and DepressionMavis E. EvansWirral and West Cheshire Community NHS Trust, Bebington, UKEPIDEMIOLOGYThe prevalence of depression in the general population worldwideis usually found to be 3–8% 1–3 . The prevalence of majordepression has been shown to be no higher in the elderly thanthe young, although these findings do not allow for the comorbidityof physical illnesses or dementias 4 . Subthreshold orminor depressions have many different names and definitions,thus causing widely differing prevalence rates to be quoted.Categorical definitions of depression do not fit well with the rangeof symptoms and severity seen in normal clinical practice.However, it is generally accepted that the burden of depressionamong the elderly is high and an accepted measure of diagnosis isnecessary to allow communication with patients, relatives andprofessional colleagues.‘‘Caseness’’ can be considered to be the severity of depression atwhich the majority of professionals would consider some form ofintervention appropriate. Prevalence of this degree of depressionis reported as 10–15% of the elderly in the community 5–6 , 15–30%of those attending primary care facilities 7–8 , 15–50% of those inhospital 8–10 and 30–40% of those in institutional care 8,11 .DIAGNOSISDepression cannot be diagnosed unless it is first considered apossibility, neither will it be appropriately treated unless it isconsidered pathological. Depression may be missed when toomuch emphasis is placed on the presenting complaints of, forexample, lethargy, anorexia or pain 12 . Depression and feelings ofworthlessness may cause failure to complain of symptoms ofphysical illness or to ask for help. It may cause non-compliancewith medication and other treatments, self-neglect or nonattendanceat clinics. Alternatively, the lowering of self-esteemand decreased ability to cope can lead to increased attendance atclinics.The lack of a concise definition for depression in the elderlymakes the establishment of validity a difficult task, which can onlybe examined by longitudinal follow-up of patients to see whathappens to their symptoms 13 . Somatic symptoms, e.g. lack ofenergy, poor concentration and weight loss, may be due to thephysical illness or ageing, not depression; even experiencedclinicians may have difficulty attributing such symptoms tophysical or psychiatric causes. Even feelings of life not beingworth living and wishing to die are not always associated withdepressed mood; poor subjective health, disability, pain, sensoryimpairment and living in an institution have been shown to beassociated factors in the absence of depressive illness 14 .The elderly tend not to admit to feelings of depression andrelatives may be unaware of the condition 15 . Somatization, ‘‘thetendency to experience and communicate somatic distress andsomatic symptoms unaccounted for by relevant pathologicalfindings, to attribute them to physical illness and to seek medicalhelp for them’’ 16 is increasingly recognized. Somatization can stilloccur in those with genuine physical illness. The somaticsymptoms of depression are similar to those of a chronic illness,such as cancer, and it must be remembered that depression andphysical illness often coexist 17 .Hypochondriasis is a recognized symptom of depression in theelderly population 18 . However, in this age group, rigorous stepsmust be undertaken to exclude physical problems before ascribingsymptoms to hypochondriasis or somatization 17,19 . That suchpatients are depressed is inferred from their good response tostandard treatments for depression 20 .The 1991 NIH Consensus Statement on diagnosis andtreatment of depression in late life concluded: ‘‘What makesdepression in the elderly so insidious is that neither the victim northe health provider may recognize its symptoms in the context ofthe multiple physical problems of many elderly people’’. DSM-4allows somatic symptoms to be counted towards the diagnosis ofdepression if there is any possibility of psychological aetiology, amore inclusive and accurate means of diagnosis than previously.MORBIDITY AND MORTALITYPsychiatric morbidity in hospitals is higher than in the generalpopulation. Surveys of wards and clinics do not completelyestablish an association between psychiatric and physical morbiditybecause they may be biased for selective referral patterns:psychological symptoms can lead to help-seeking behaviour forphysical illness in an individual who had previously been able totolerate his/her physical problems. Similarly, they may influence aGP on whether or not to refer to hospital. Stress may be asimportant in triggering help-seeking behaviour as in triggeringactual illness. In addition to the degree of distress, many otherfactors determine whether or not an individual will seek help,including religious and social values, socioeconomic backgroundand personality.Affective disorder in the elderly is strongly associated withphysical ill-health 19 : ‘‘whether or not such an illness has a directaetiological relationship to the affective disorder, its practicalimportance must be considered, for it is bound to influence thecourse and outcome of the psychiatric condition’’. Other studieshave found that depression leads to increased mortality 21–23 overand above age effects, the prognosis worsening with severity ofPrinciples and Practice of Geriatric Psychiatry, 2nd edn. Edited by J. R. M. Copeland, M. T. Abou-Saleh and D. G. Blazer&2002 John Wiley & Sons, Ltd