AP PSYCHOLOGY

Detailed explanation-1: -These data suggest that the COMT Val allele, because it increases prefrontal dopamine catabolism, impairs prefrontal cognition and physiology, and by this mechanism slightly increases risk for schizophrenia.

Detailed explanation-2: -A diathesis–stress model for schizophrenia was originally proposed by Manfred Bleuler17 and David Rosenthal. This model described schizophrenia as a result of a complex interaction between multiple genes and adverse environmental risk factors, none of which causes schizophrenia on their own.

Detailed explanation-3: -COMT is involved in catabolizing catecholamines such as dopamine. These neurotransmitters appear to be involved in regulating mood which can contribute to aggression. The most common gene variant studied in the COMT gene is the Valine (Val) to Methionine (Met) substitution at codon 158.

Detailed explanation-4: -Genetic evidence : The COMT gene is found in a region of the 22nd chromosome of the human genome which is shown in genetic linkage studies for harbouring schizophrenia genes. Individuals with a deletion in this region (1/ 4000 human births) have 30 times more likelihood of developing schizophrenia.