Changing BDNF Levels with Depression Treatment

Doctor Abraham Zangen describes how transcranial magnetic stimulation (TMS) may affect levels of BDNF in the hippocampus, thereby treating depression.

One of the markers today associated with depression is reduction in brain-derived neurotrophic factor [BDNF], which is a protein important for neural plasticity for the ability of the brain to learn to change. So this factor which again is a big protein is involved in many processes in the brain. It was found that in depressive subjects the levels of this protein are lower especially in a region called the hippocampus Antidepressant drugs - repeated use of antidepressant drugs causes elevation of this factor. We actually studied what happens if we induce a reduction in this factor in animals and looked at the battery of behavioral tests and found that reduction of this factor would cause depressive-like behavior in animal models. Now, what brain stimulation is doing, electrical stimulation or magnetic stimulation that I mentioned before is to actually increase this factor in hippocampus and we found this to happen only after repeated stimulations. It is not enough to give one session of brain stimulation to induce increased BDNF (brain-derived neurotrophic factor) levels, you need several sessions and also the behavior, I mean, the normalization of behavior in animal models or in humans is shown only after repeated stimulation. There is correlation between the elevation of the brain-derived neurotrophic factor levels in the hippocampus and the normalization of the behavior.