Posted by Pfinstegg on February 13, 2006, at 18:25:20
in the dopamine reward pathways of the brain are altered in depression, PTSD and social withdrawal. (Science, Vol 311, 10 February, 2006).
This article describes how "bullied mice" (those subjected to a larger, aggressive mouse) developed symptoms of social defeat, mediated by BDNF in the dopaminergic mesolimbic pathways- the "reward system". The presence of BDNF was essential for this learned defeat and social withdrawal. Either knocking out BDNF in this pathway, or administering fluoxetine, prevented this from happening. Up until now, attention has focussed on preserving BDNF and serotonin in the hippocampus and other nearby areas, in the treatment of these symptoms, which many antidepressants, including fluoxetine, are thought to do.
I thought it was interesting that the dopaminergic pathways are emerging as important areas in depression and PTSD, and also that while BDNF is considered important in maintaining a healthy hippocampus, and is vital to memory and new learning, it could be one of the neurotransmitters in learned social defeat and depression
I have always been aware that absence of a sense of reward is one of the biggest difficulties when one is depressed. But I've also noticed, from personal experience and from many posts here, that long-term use of SSRIs and SNRIs can make that symptom even worse, even though, according to this article, it is supposed to preserve the sense of reward in social interactions despite social stress.
poster:Pfinstegg
thread:609248
URL: http://www.dr-bob.org/babble/20060212/msgs/609248.html