Medical comorbidity in late-life depression

Medical comorbidity is common in elderly patients with depression, however the difference between depressed and non-depressed elderly populations is not well established. Additionally, differences between subgroups of depressed populations, including those with MRI-defined vascular depression and those with late-onset compared with early-onset depression are not well described.

We compared self-report of medical disorders between 370 depressed elders and 157 non-depressed control subjects. Subjects were additionally dichotomized based on presence or absence of subcortical MRI lesions and age of onset. Medical comorbidity was assessed by self report only, and depressed subjects were additionally assessed by the clinician-rated Cumulative Illness Rating Scale.

When compared with the non-depressed group, depressed subjects were significantly more likely to report the presence of hypertension, heart disease, gastrointestinal ulcers, and 'hardening of the arteries'. Analyses of subjects with subcortical disease demonstrated they were significantly older, more likely to have depression, and more likely to report the presence of hypertension. Finally, the depressed cohort with late-onset depression (occurring after age 50 years) had more male subjects, exhibited greater CIRS scores, and greater prevalence of hypertension, but these did not reach a level of statistical significance after applying a Bonferroni correction.

Vascular comorbidities are common in depressed elders. The differences in the report of hypertension supports past work investigating a vascular contribution to late-life depression. Given the association between depression and poor medical outcomes of cardiac disease, this population deserves clinical scrutiny and further research.