COMT Met (158) modulates facial emotion recognition in bipolar I disorder mood episodes.
BACKGROUND
One of the many cognitive deficits reported in bipolar disorder (BD) patients is facial emotion recognition (FER), which has recently been associated with dopaminergic catabolism. Catechol-O-methyltransferase (COMT) is one of the main enzymes involved in the metabolic degradation of dopamine (DA) in the prefrontal cortex (PFC). The COMT gene polymorphism rs4680 (Val158Met) Met allele is associated with decreased activity of this enzyme in healthy controls. The objective of this study was to evaluate the influence of Val158Met on FER during manic and depressive episodes in BD patients and in healthy controls.


METHODS
64 BD type I patients (39 in manic and 25 in depressive episodes) and 75 healthy controls were genotyped for COMT rs4680 and assessed for FER using the Ekman 60 Faces (EK60) and Emotion Hexagon (Hx) tests.


RESULTS
Bipolar manic patients carrying the Met allele recognized fewer surprised faces, while depressed patients with the Met allele recognized fewer "angry" and "happy" faces. Healthy homozygous subjects with the Met allele had higher FER scores on the Hx total score, as well as on "disgust" and "angry" faces than other genotypes.


CONCLUSIONS
This is the first study suggesting that COMT rs4680 modulates FER differently during BD episodes and in healthy controls. This provides evidence that PFC DA is part of the neurobiological mechanisms of social cognition. Further studies on other COMT polymorphisms that include euthymic BD patients are warranted. Clinicaltrials.gov identifier: NCT00969.
Mood Disorders Unit (GRUDA), Department and Institute of Psychiatry, School of Medicine, University of São Paulo (IPq HC-FMUSP), Brazil. mgss@usp.br
Márcio Gerhardt
MG
Soeiro-de-Souza
Danielle Soares
DS
Bio
Denise Petresco
DP
David
Domingos
D
Rodrigues dos Santos
Daniel Shikanai
DS
Kerr
Wagner Farid
WF
Gattaz
Rodrigo
R
Machado-Vieira
Ricardo Albeto
RA
Moreno
D000328:Adult; D001714:Bipolar Disorder / Q000235:genetics* / Q000523:psychology; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D004644:Emotions; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D021641:Recognition, Psychology; D055815:Young Adult
D002394:Catechol O-Methyltransferase