An fMRI study of prefrontal brain activation during multiple tasks in patients with major depressive disorder

Objective: Previous research has provided conflicting information regarding the pattern of brain activation associated with cognitive performance in depressed people. We aimed to assess brain activation related to cognitive performance during planning and working memory tasks. Method: fMRI scans were conducted using a modified Tower of London task and a 2-back task in 13 patients with major depressive disorder and a matched control group. Results: Task performance was impaired in the depressed group on the Tower of London task but there were no differences between the groups in task performance on the n-back task. The patient group showed widespread increased brain activation in both tasks. There was considerable overlap in increased activation between the two tasks, especially in right prefrontal cortical regions. Conclusions: Patients with depression exhibit increased brain activation, especially in right prefrontal regions, across several types of cognitive task activity. Patients with depression may recruit greater brain regions to achieve similar or even poorer task performance than control subjects.