A pilot study exploring the association of morphological changes with 5-HTTLPR polymorphism in OCD patients

BACKGROUND: Clinical and pharmacological studies of obsessive-compulsive disorder (OCD) have suggested that the serotonergic systems are involved in the pathogenesis, while structural imaging studies have found some neuroanatomical abnormalities in OCD patients. In the etiopathogenesis of OCD, few studies have performed concurrent assessment of genetic and neuroanatomical variables. METHODS: We carried out a two-way ANOVA between a variable number of tandem repeat polymorphisms (5-HTTLPR) in the serotonin transporter gene and gray matter (GM) volumes in 40 OCD patients and 40 healthy controls (HCs). RESULTS: We found that relative to the HCs, the OCD patients showed significant decreased GM volume in the right hippocampus, and increased GM volume in the left precentral gyrus. 5-HTTLPR polymorphism in OCD patients had a statistical tendency of stronger effects on the right frontal pole than those in HCs. CONCLUSIONS: Our results showed that the neuroanatomical changes of specific GM regions could be endophenotypes of 5-HTTLPR polymorphism in OCD.