Increased hippocampal BDNF immunoreactivity in subjects treated with antidepressant medication

Background: The cAMP signaling pathway, and its downstream neurotrophic fac tor BDNF, are major targets of antidepressant medications. Abnormalities in this pathway have previously been reported in postmortem brain of subjects with mood disorders. This study was designed to test whether the diagnosis of a mood disorder, or treatment with an antidepressant or mood stabilizer was associated with changes in hippocampal BDNF in postmortem brain. Methods: Frozen postmortem anterior hippocampus sections it-ere obtained fr om the Stanley Foundation Neuropathology Consortium. Tissue from subjects w ith major depression, bipolar disorder, schizophrenia and nonpsychiatric co ntrol subjects were stained for BDNF using immunohistochemistry Results: Increased BDNF expression was found in dentate gyrus, hilus and su pragranular regions in subjects treated with antidepressant medications at the time of death, compared with antidepressant-untreated subjects. Further more, there was a trend toward increased BDNF expression in hilar and supra granular regions in depressed subjects treated with antidepressants, compar ed with the subjects not on these medications at the time of death. Conclusions: These findings are consistent with recent studies measuring CR EB levels in this same subject sample, and support current animal and cellu lar models of antidepressant function. (C) 2001 Society of Biological Psych iatry.