Associations between polymorphic variants of the tryptophan hydroxylase 2 gene and obsessive-compulsive disorder.

Objective: A substantial body of evidence suggests that obsessive-compulsive disorder has a genetic component, and substantial candidate genes for the disorder have been investigated through association analyses. A particular emphasis has been placed on genes related to the serotonergic system, which is likely to play an important role in the pathogenesis of obsessive-compulsive disorder. The gene for tryptophan hydroxylase 2, which is a rate limiting enzyme in serotonin synthesis, is considered an important candidate gene associated with psychiatric disorders.

Decision-making impairment is related to serotonin transporter promoter polymorphism in a sample of patients with obsessive-compulsive disorder.

Objective: Decision-making impairment is an important feature of some psychiatric disorders, such as attention-deficit/hyperactivity disorder and substance-use disorders, and is associated with dysfunction of the fronto-subcortical circuit, mainly the orbitofrontal cortex (OFC). Several data reports support significant correlations between decision-making impairment and the serotonin system. Thus, this neurotransmission system may be a major step in some cognitive features, particularly in OCD because serotonin is associated with this disorder.