[Brain-derived neurotrophic factor (BDNF) and mood disorder].

Brain-derived neurotrophic factor (BDNF) is the most abundant and widely expressed neurotrophin in the brain. BDNF is believed to play an important role in depressive disorder. Chronic stress decreases the synthesis of hippocampal BDNF, which leads to atrophy of the hippocampus in the depressed patients. Blood BDNF levels also decreased in depressed patients and a correlation is observed between severities of depressive state and blood BDNF levels. Selective serotonin reuptake inhibitors and serotonin noradrenalin reuptake inhibitors both recover the decreased blood BDNF levels. These findings indicate that the blood BDNF level is one of the candidate biomarkers for depression.