Neuropsychological measures of declarative memory and verbal fluency predict clinical response to cognitive behavioral treatment in patients with unipolar depression

Cognitive-behavioral therapy (CBT) and sleep deprivation (SD) are both effective in treating major depression (MD). Since patients with MD often have deficits in various cognitive domains, the study aimed to clarify whether these variables also contribute to the prediction of clinical outcome following CBT without vs. with additional SD. According to randomization, 19 drug-free and middle-aged inpatients with DSM-IV diagnosis of MD received CBT over 3 weeks (5 sessions/week) either as monotherapy or combined with additional SD (2 nights of total SD/week). At baseline, patients underwent neuropsychological testing and ratings of depressive symptomatology (Hamilton Depression Rating Scale, HDRS), the latter were also conducted after each treatment week. Irrespective of assignment to mono- or combination therapy, over 50% of patients showed a clinical meaningful improvement of depressive symptomatology. Significant positive relationships between measures of cognitive performance and clinical improvement were specifically observable in the CBT monotherapy group. Hierarchical regression revealed that performance in delayed recognition and word fluency predicted 71% of the variance in HDRS improvement following CBT monotherapy whereas no such prediction was obtained in the combination group. These results suggest a predictive role of cognitive functioning in MD for benefiting from CBT, which appears to be abolished by additive treatments with cognitive side effects such as SD. This study was supported by BMBF