Gene, brains, and environment-genetic neuroimaging of depression

Depression, conceptualized as major depressive disorder (MDD), is a complex psychiatric disorder with multiple behavioral changes and alterations in various brain regions. Biochemically, serotonin and others substances like GABA, glutamate, norepinephrin, adrenaline/noradrenaline play an essential role in the pathogenesis of MDD. The paper reviews recent human neuroimaging findings on how the genes underlying these biochemical substances modulate neural activity, behavior, and ultimately clinical symptoms. Current data provide solid evidence that genes related to serotonin impact emotion-related neural activity in the amygdala and the anterior cingulate cortex. By contrast, evidence is not as strong for genes related to biochemical substances other than serotonin and other regions of the brain. The review concludes with discussing future genetic, neural, and clinical challenges that point out the central role of gene × environment and brain × environment interactions as genetic and neural predispositions of depression.

► Depression is a multifaceted disorders that includes neural, social, and genetic dimensions. ► Genetic neuroimaging focused on serotonin-related genes and their different polymorphisms. ► Serotonin-related genes have been explored strongly in depression with abnormal polymorphisms and neural abnormalities. ► Emotion processing in the amygdala is modulated by specific polymorphisms in serotoninergic genes. ► Genetic predispositions describe the liability or susceptibility to specific environmental constellation.