Mortality associated with incident mental health disorders after stroke

Abstract

Objective: Sparse information is currently available about the incidence of the major psychiatric syndromes following a stroke and their long-term contribution to morbidity and mortality. This study was designed to determine: (1) the incidence of first ever mental health disorder in amongst stroke patients; (2) the 10-year mortality associated with incident post-stroke mental health disorders.

Design: Retrospective cohort study.

Setting: Entire Western Australian community.

Participants: First-ever stroke in 1990. Subjects with a prior recorded history of any mental health disorder were excluded from the study. Main outcomes of interest: Incident mental health diagnoses and 10-year mortality.

Results: 1,129 hospital stroke contacts were recorded in 1990, with 21 people dying on the same day of contact. Between 1990-2002 36.6% of the survivors received a mental health diagnosis (6.1 per 1,000 person-years): alcohol-related disorders (16.2%), dementia (12.1%), delirium (7.6%), psychotic disorders (6.7%), and depression (5.5%). Mental health disorder onset was usually within 6 months of the stroke. Patients with an incident psychotic disorder were twice as likely to die during the subsequent 10 years as post-stroke controls with no mental health disorder (risk ratio = 2.03, 95%CI = 1.39-2.95). Being a widow (HR = 1.61, 95%CI = 1.13-2.30) or having been born in 'other countries' as opposed to Australia (HR = 1.56, 95%CI = 1.15-2.11) was also associated with increased death hazard.

Conclusions: Approximately 1 in 3 patients develop a mental health disorder after stroke, although incidence estimates are relatively low. Post-stroke psychosis is associated with greater 10-year mortality, but the mechanisms underlying such an association are yet to be determined.