The effects of depression and abnormal illness behaviour on outcome following rehabilitation from stroke

Abstract

Objective: To examine the relative effects of depression and abnormal illness behaviour (AIB) on long-term rehabilitation outcome following stroke. Design: A longitudinal design, with assessments on admission to and discharge from rehabilitation, and six and twelve months after discharge. Setting: The study was undertaken in the rehabilitation unit at Repatriation General Hospital, in Adelaide, South Australia. Subjects: Ninety-four twelve-month stroke survivors who had undergone an inpatient rehabilitation programme. Main outcome measures: AIB was assessed using the Illness Behaviour Questionnaire, and depression with the Zung Self-Rating Depression Scale. The General Health Questionnaire and a visual analogue mood scale were also used. Functional outcome was assessed with the competence and performance assessments of the Australian ADL Index, and lifestyle activities with the Frenchay Activities Index. Results: Multivariate analysis of outcome controlled for age and stroke severity. AIB was a better predictor of functional competence and performance than either age or stroke severity, at rehabilitation discharge and both six and twelve months later. Depression was not related to functional competence and performance at any assessment, but was strongly predictive of an inactive lifestyle at both six and twelve months. By contrast, lifestyle activities were not related to AIB. Conclusions: Depression and AIB appear to have quite distinct effects on outcome. AIB emerged as a key determinant of long-term functional disability, while depression was associated with poorer social functioning. The early recognition and treatment of AIB and depression is important for the ultimate social and functional outcomes of stroke rehabilitation patients.