Objective: The long-term cognitive effect of antidepressant medications in older persons is not well understood, especially in those with minor depression and complex medical conditions. The objective of this study is to examine this relationship in older medical patients with different depression diagnoses.
Methods: 281 medical inpatients aged 65 years and older from 2 acute care hospitals in Montreal, Canada, were diagnosed as with major or minor depression or without depression according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria. They were followed up with the Mini-Mental State Examination for cognitive function and the Hamilton Depression Rating Scale for depressive symptoms at baseline and 3, 6, and 12 months after discharge. Antidepressant medication was ascertained from a provincial prescription database and quantified as cumulative exposures over each follow-up interval.
Results: During the 12-month follow-up period, 1027 antidepressant prescriptions were filled. The most frequently prescribed antidepressant agents were citalopram (0.81 prescriptions per person), sertraline (0.76), and paroxetine (0.66). Antidepressant use was not associated with cognitive changes among patients with major depression or without depression but was associated with an increased Mini-Mental State Examination score in patients with minor depression (1.4 points; 95% confidence interval, 0.1-2.6), independent of change in the severity of depression symptoms, concomitant benzodiazepine or psychotropic drug use, and other potentially important confounders.
Conclusions: In this cohort of older medical patients, antidepressant use for 12 months did not lead to significant cognitive impairment. The small cognitive improvement among minor depression associated with antidepressant use deserves further investigation.