5-HTT genotype effect on prefrontal-amygdala coupling differs between major depression and controls.
BACKGROUND
In major depression, prefrontal regulation of limbic brain areas may be a key mechanism that is impaired during the processing of affective information. This prefrontal-limbic interaction has been shown to be modulated by serotonin (5-HTT) genotype, indicating a higher risk for major depressive disorder (MDD) with increasing number of 5-HTT low-expression alleles.


OBJECTIVE
Functional magnetic resonance imaging was used to assess neural response to uncued unpleasant affective pictures in 21 unmedicated patients with MDD compared to 21 matched healthy controls, taking into account genetic influences of the 5-HTT (SCL6A4) high- and low-expression genotype.


RESULTS
Healthy controls displayed greater prefrontal activation (BA10) to uncued negative pictures compared to patients with MDD. While in healthy controls prefrontal (BA10) activation and BA10-amygdala coupling increased with the number of 5-HTT low-expression risk alleles, this effect was abolished, and even reversed, in patients with MDD. In MDD, connectivity decreased with severity of depressive symptoms (HAMD total score).


CONCLUSIONS
These findings suggest that increased medial prefrontal (BA10) activation and BA10-amygdala connectivity may counteract the risk for MDD in healthy carriers of 5-HTT low-expression alleles, while this protective factor might be lost in patients who actually suffer from MDD. Prefrontal-limbic regulation in risk populations could be a target of early interventions and should be the focus of further research.
Friedel
Eva
E
Department of Psychiatry, Charité University Medicine Berlin, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany. eva.friedel@charite.de
Schlagenhauf
Florian
F
Sterzer
Philipp
P
Park
Soyoung Q
SQ
Bermpohl
Felix
F
Ströhle
Andreas
A
Stoy
Meline
M
Puls
Imke
I
Hägele
Claudia
C
Wrase
Jana
J
Büchel
Christian
C
Heinz
Andreas
A
D000328:Adult; D000339:Affect / Q000502:physiology; D000679:Amygdala / Q000098:blood supply / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003463:Cues; D003865:Major Depressive Disorder / Q000235:genetics* / Q000473:pathology*; D005260:Female; D005838:Genotype; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000098:blood supply / Q000503:physiopathology; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D017397:Prefrontal Cortex / Q000098:blood supply / Q000503:physiopathology*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011569:Psychiatric Status Rating Scales; D011601:Psychophysics / Q000379:methods; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013997:Time Factors
C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D010100:Oxygen