BDNF and psychiatric disorder: Our findings indicate that, whereas BDNF mRNA is decreased in all three diagnostic groups in cingulate and temporal cortices, the frontal cortex is more affected in schizophrenia and the hippocampus is more affected in mood disorders.17 This anatomical separation of BDNF/trkB−TK+ signaling deficits may reflect the differences in affective symptoms that manifest between the different mental disorders.