Rates of depression at 3 and 15 months poststroke and their relationship with cognitive decline: the Sydney Stroke Study

Objective: To investigate the frequency and correlates of depression at 3 and 15 months after stroke. Methods: A total of 164 consecutive eligible stroke patients and 100 comparison subjects received extensive medical, psychiatric, and neuropsychological assessments; a subset also received magnetic resonance imaging scans. Comprehensive assessments included ratings for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition major or minor depression at 3 - 6 months ( index assessment) and 15 months ( follow-up assessment) after stroke. The comparison subjects, who were similar in age and sex, were similarly assessed twice, 12 months apart. Results: Major or minor depression was present in 12.0% of stroke patients at index assessment and in 20.7% at follow-up which included 18 new cases (13.4%). By follow-up, stroke patients with depression had significantly greater impairment of functional ability and global cognition than nondepressed stroke patients or comparison subjects. Depression was not associated with age, intellectual decline prior to stroke or side or severity of stroke. Patients who experienced a TIA or stroke during the follow-up, who had developed dementia by three months or who were not living with a relative or partner were more likely to be depressed at follow-up. Dementia at 3 months predicted depression, but the reverse did not hold. Conclusion: Depression may be less frequent after stroke than previously reported and is related to cumulative vascular brain pathology rather than side and severity of single strokes. Clinicians should strive to slow the progression of cerebrovascular disease and encourage greater social support.