A meta-analysis of studies comparing the symptom profiles of younger and older patients with major depression has found that older people are more likely to present with agitation, somatic symptoms and hypochondriasis, whereas younger people are more likely to present with guilt and loss of libido.

Eleven studies met the inclusion criteria. The total number of patients included was 2011. There was no consensus regarding the boundary between youth and old age, which ranged from 50 to 65.

Major depression was diagnosed according to DSM, RDC (Research Diagnostic Criteria) or ICD criteria; the 17-item Hamilton Rating Scale for Depression (HAM-D) was used to measure the prevalence and severity of depressive symptoms.

The HAM-D measures depression severity; it is not a diagnostic tool. Hence, it includes a number of symptoms, such as anxiety and musculoskeletal pain, which are not included in the diagnostic criteria for major depression but which nevertheless reflect its severity.¹

Four HAM-D items were significantly more prevalent and/or severe in older patients: hypochondriasis, general somatic symptoms (backache, headache, muscle aches, fatigue or heaviness of the limbs), agitation, and gastrointestinal somatic symptoms (loss of appetite).

Two HAM-D items were significantly more prevalent and/or severe in younger patients: guilt and loss of libido.

There are a number of possible explanations for the increased prevalence of somatic symptoms among elderly depressed patients:

• Older people come from a generation where the expression of emotions was discouraged, and are therefore more likely to deny feeling depressed and to present with somatic symptoms.²

• Somatic symptoms may be caused by comorbid physical health problems or ageing itself, rather than depression.

• Depression may amplify somatic symptoms associated with chronic physical health problems, and have a detrimental effect on prognosis.

• Clinical subtypes of depression in older people e.g. vascular depression3 may have distinctive symptom profiles.

Most of the participants were inpatients, and the remainder were seen in outpatient clinics. We should be wary of generalising the results to primary care patients, many of whom may not meet conventional diagnostic criteria.⁴

Recognition and diagnosis of depression in older patients is difficult, resulting in undertreatment and a poor prognosis: a meta-analysis of primary care studies found that half of the surviving patients remained depressed at two-year follow-up.⁵

We need to increase our awareness of somatic and behavioural presentations, avoid over-rigid application of diagnostic criteria and beware of misdiagnosing physical illness as depression.

Dr Phillip Bland

• Hegeman JM, Kok RM, van der Mast RC, Giltay EJ. Phenomenology of depression in older compared with younger adults: meta-analysis. Br J Psychiatry 2012;200:275-81