Event-related functional magnetic resonance imaging measures of neural activity to positive social stimuli in pre- and post-treatment depression.
BACKGROUND
Relationships between aberrant social functioning and depression have been explored via behavioral, clinical, and survey methodologies, highlighting their importance in the etiology of depression. The neural underpinnings of these relationships, however, have not been explored.


METHODS
Nine depressed participants and 14 never-depressed control subjects viewed emotional and neutral pictures at two functional magnetic resonance imaging (fMRI) scanning sessions approximately 22 weeks apart. In the interim, depressed patients received the antidepressant Venlafaxine. Positively rated images were parsed into three separate comparisons: social interaction, human faces, and sexual images; across scanning session, activation to these images was compared with other positively rated images.


RESULTS
For each of the three social stimulus types (social interaction, faces, sexual images), a distinguishable circuitry was activated equally in non-depressed control subjects and post-treatment depressed subjects but showed a hypo-response in the depressed group pre-treatment. These structures include regions of prefrontal, temporal, and parietal cortices, insula, basal ganglia, and the hippocampus.


CONCLUSIONS
The neural hypo-response to positively valenced social stimuli that is observed in depression remits as response to antidepressant medication occurs, suggesting a state-dependent deficiency in response to positive social incentives. These findings underscore the importance of addressing social dysfunction in research and treatment of depression.
Schaefer
Hillary S
HS
Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin-Madison, Madison, Wisconsin 53705-2280, USA.
Putnam
Katherine M
KM
Benca
Ruth M
RM
Davidson
Richard J
RJ
D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use; D001921:Brain / Q000098:blood supply / Q000503:physiopathology; D001931:Brain Mapping; D003863:Depression / Q000175:diagnosis* / Q000188:drug therapy / Q000523:psychology*; D004644:Emotions / Q000187:drug effects / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007398:Interpersonal Relations; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D012737:Sex Factors; D016896:Treatment Outcome; D014796:Visual Perception / Q000502:physiology
D000928:Antidepressive Agents; D010100:Oxygen