BDNF, Hippocampus and Depression

Proposal details

Title: BDNF, Hippocampus and Depression
Research Area(s): Emotion and Self Regulation
Background: There are several pertinent findings in the literature to date that document an inter-relationship between BDNF, depression and the hippocampus.Several studies document reduced hippocampal volume in depressed subjects which may be related to impaired neurogenesis in the hippocampus. Stress decreases adult neurogenesis. The link to depression may be through hyperactivity of the hypothalamic-pituitary-adrenal axis observed in major depression and the associated secretion of neurotoxic cytokines. Furthermore, most antidepressants increase neurogenesis and block the effects of stress on adult neurogenesis. BDNF is reduced in depressed subjects. Antidepressant treatment induces BDNF expression in pharmacological studies and post-mortem studies report increased BDNF in brain of subjects on antidepressants. Some but not all studies report an association between the val66met polymorphism and both bipolar disorder and major depression. The prevailing theory is that BDNF is altered in depression accounting for the reduced hippocampal volume and it follows that as depresson has a genetic etiology that variants in the BDNF gene may be of etiological importance. The link between hippocampal volume, depressive symptoms and the possible link to BDNF requires further study in unraveling the biology of depressive illness.
Aims: The specific aim is to evaluate the relationship between hippocampal morphology, mood symptoms and the val66met polymorphism. Specifically to evaluate the relationship between mood measures (depression scores on the DASS), as a continuous variable, and hippocampal volume (MRI data)and to determine whether this relationship is different in variants of the val66met polymorphism from the BDNF data
Method: To examine the relationship between DASS scores, hippocampal volume from MRI's and val/val vs. val/met polymorphisms in subjects in the database.