Cognitive predictors of treatment response to bupropion and cognitive effects of bupropion in patients with major depressive disorder.

Cognitive effects of antidepressants and cognitive predictors of antidepressant treatment response are recent focuses of interest in the neuropsychology of depression. We studied the cognitive predictors of treatment response to bupropion and its neuropsychological effects in patients with major depressive disorder. Twenty subjects meeting the DSM-IV criteria for major depressive disorder were assessed with the Hamilton Depression Rating Scale and a neuropsychological battery. Subjects were medicated with 150 mg/day of bupropion sustained release for 8 weeks. At the end of the trial, 12 subjects were classified as responders to treatment and 8 were non-responders. Our findings suggest that low pretreatment measures of visual memory and low levels of mental processing speed are predictive of good response to bupropion. The cognitive effects of bupropion after the treatment showed that patients improved in visual memory measures and in mental processing speed. Our results suggest that cognitive predictors of treatment response to bupropion and cognitive effects of bupropion in patients with major depressive disorder could be closely related. These findings need to be replicated due to the exploratory nature of the present work.