Increased left prefrontal activation in patients with unipolar depression: an event-related, parametric, performance-controlled fMRI study.
BACKGROUND
Executive deficits associated with frontal lobe dysfunction are prominent in depression. We applied a newly developed WM task to investigate the neural correlates of executive processes with functional magnetic resonance imaging (fMRI) at comparable performance levels analyzing correct trials only.


METHODS
We studied 12 partially remitted, medicated inpatients meeting DSM-IV criteria for major depressive disorder and 17 healthy controls. We used a parametric version of a delayed match-to-sample WM task requiring manipulation of verbal material during a delay period in an event-related fMRI design.


RESULTS
Depressed patients were generally slower and load-dependently less accurate than healthy controls. Patients showed significantly more activation of left dorsolateral prefrontal cortex with highest cognitive load. Additionally, they showed higher activation in ventromedial prefrontal cortex during the control condition.


CONCLUSIONS
The fact that patients were taking different antidepressant drugs could limit the explanatory power of the present results.


CONCLUSIONS
Increased lateral prefrontal activation despite comparably successful performance - when only correct trials were analyzed - in patients with depression can be interpreted as evidence for compensatory recruitment of prefrontal cortical resources.
Walter
Henrik
H
Department of Psychiatry, Division of Medical Psychology, University Clinic Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn, Germany.
Wolf
Robert Christian
RC
Spitzer
Manfred
M
Vasic
Nenad
N
D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D004193:Discrimination Learning / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011930:Reaction Time / Q000502:physiology*