Age at onset of schizophrenia: interaction between brain-derived neurotrophic factor and dopamine D3 receptor gene variants.

One of the main features of schizophrenia is its age at onset in early adulthood. Dopaminergic dysregulation is the most documented neurobiological factor that may be involved in triggering schizophrenia. Recent findings on neurodevelopmental processes show that the brain-derived neurotrophic factor plays a critical role in the development of mesolimbic dopaminergic-related systems and regulates the expression of dopamine D3 receptors. In this study, we examine whether an interaction between dopamine D3 receptors and brain-derived neurotrophic factor gene variants influences age at onset in patients with schizophrenia. Our findings show that this gene-gene interaction was significantly associated with an earlier emergence of psychosis by 3 years.