Mood disorders after stroke and their relation to lesion location. A CT scan study.

In a community-based study of stroke survivors, we identified 73 consecutive patients with a stroke, the first ever in a lifetime, who had a CT scan which showed a neurologically appropriate single stroke lesion, and who did not have a psychiatric disorder in the year preceding the stroke. A detailed follow-up study of these patients using standardized psychiatric assessments failed to confirm a number of recent claims about poststroke depressive disorders. We found no evidence that left-sided lesions were associated with more severe or persistent depressive symptoms, or that right-sided lesions were associated with hypomania. The DSM III syndrome of major depression was much less common than has previously been reported, and was not specifically associated with lesions placed anteriorly in the left hemisphere. There was a weak correlation between mood symptom scores and the proximity of the stroke lesion to the frontal pole of the hemisphere, but no evidence of a difference between right and left hemisphere strokes in the nature of the relationship between lesion distribution and mood symptoms. We suggest that previous studies have different findings because of differences in the conventions applied to the definition and measurement of psychiatric disorders after stroke, and because other studies have concentrated on selected inpatient populations.