Enhancing effect of mirtazapine on cognitive functions associated with prefrontal cortex in patients with recurrent depression.

INTRODUCTION We put forward a hypothesis that a therapeutic administration of mirtazapine to depressed patients, due to pharmacological profile of the drug, could enhance cognitive functions associated with prefrontal cortex activity. METHODS The study was performed on depressed patients receiving mirtazapine for the period of 6 months. Neuropsychological assessments after 3 and 6 months of treatment were performed by the Wisconsin Card Sorting Test, N-back test, TMT and Stroop tests. RESULTS During acute depressive episode, a significant impairment on all neuropsychological tests was evident. Substantial improvement in performance has been noted after 3 and 6 months of mirtazapine treatment, and, after 6 months, a majority of the investigated patients achieved the results within the range of matched healthy control subjects. Improvement on neuropsychological tests after treatment with mirtazapine showed no correlation with the degree of amelioration of depression. DISCUSSION Mirtazapine may exert a favorable influence on cognitive functions associated with prefrontal cortex in depressed patients. The lack of direct correlation with improvement of depressive symptoms suggests that mirtazapine may possess specific pro-cognitive properties.