Body dysmorphic disorder typically manifests during adolescence. It is not yet clear what exactly causes BDD, and it’s likely that multiple factors contribute to the development of the disorder.
Research suggests a genetic (and thus hereditary) component in BDD because individuals are more susceptible to the disorder if they have a family member affected by BDD or OCD. So far, only a few gene mutations have been identified as potentially contributing to the development of BDD, and these mutations are located on the gamma-aminobutyric acid (GABA)A-γ2 gene and the serotonin transporter gene.[1][2][3][4]
Developmental factors (e.g., child emotional and/or physical abuse) and social factors (e.g., being bullied about a specific body flaw) may also contribute to the development of BDD, according to some studies.[5]
Additionally, functional magnetic resonance imaging (fMRI) has been used to scan BDD subjects while they perform a photo match task. In these fMRI studies, participants with BDD showed altered activity in the right hemisphere of the brain, compared to participants without BDD, and hypoactivity in the visual cortical systems and occipital regions, which may affect visual perception and/or visuospatial processing.[6][7] Another study also detected a dysfunction in the frontal-striatal circuits of the brain, which are responsible for the perception and manipulation of information, among other functions.[8] Further studies on the brain morphometry of participants with BDD displayed some differences compared to control participants without BDD, but the results across studies were inconsistent, and more research is needed.[5]
Furthermore, the involvement of the serotonin system in BDD is under investigation, with some studies showing that by modulating the serotonin response, BDD symptoms may be exacerbated or attenuated. However, a direct causal relationship between serotonin and BDD has yet to be established.[5]