Aggressive behaviour in patients with schizophrenia is associated with catechol-O-methyltransferase genotype.
BACKGROUND
Evidence exists for an association between aggression and schizophrenia. Although the aetiology of aggression is multifactorial, three studies have reported associations between polymorphisms of the catechol-O-methyltransferase (COMT) gene and aggression in schizophrenia.


OBJECTIVE
To replicate these findings in a larger sample using the Overt Aggression Scale (OAS).


METHODS
A sample of 180 people with DSM-IV schizophrenia were rated for aggression using the OAS. Kruskal-Wallis and contingency table analyses were applied to the OAS results.


RESULTS
The high-activity homozygotes showed significantly higher scores of aggression, whereas the heterozygotes showed significantly lower scores. The odds ratio for aggression for the high-activity homozygotes was 2.07 (95% Cl=1.03-4.15), whereas that for the heterozygotes was 0.54 (95% Cl=0.30-1.00). CONCLUSIONS; The high-activity COMT homozygote confers a higher risk of recorded aggression in schizophrenia. Heterozygotes had a significantly lower risk, which may represent an example of heterosis/heterozygote advantage.
Jones
G
G
Department of Psychological Medicine, University of Wales College of Medicine, Cardiff, Wales, UK.
Zammit
S
S
Norton
N
N
Hamshere
M L
ML
Jones
S J
SJ
Milham
C
C
Sanders
R D
RD
McCarthy
G M
GM
Jones
L A
LA
Cardno
A G
AG
Gray
M
M
Murphy
K C
KC
Owen
M J
MJ
D000374:Aggression; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D016009:Chi-Square Distribution; D005260:Female; D006720:Homozygote; D006801:Humans; D008297:Male; D012559:Schizophrenia / Q000235:genetics*; D012565:Schizophrenic Psychology
D002394:Catechol O-Methyltransferase