Neurobiology of Depression

Psychologists in England recently declared war on psychiatry and the "bio-medical model" of mental illness. I'll have more to say soon on this, as well as on the controversies around the new Diagnostic and Statistical Manual of Mental Disorders.  For now, however, I will just say the the psychologists are fighting a rear-guard retreat, though they don't yet seem aware that this is the case. The accumulating evidence that depression, in particular is indeed a medical—that is, a physiological—condition  is becoming overwhelming.

A recent development on this front: the work of Eric J. Nestler, MD, Ph, who is working on developing a model for human depression in mice.  A short video, in which he discusses his work:





 (also available here)


A few things caught my attention here, in particular the fact that mice who are placed into some analog to depression via social stress  respond to the same anti-depressants that are prescribed for humans. This is important for two reasons: First,  it confirms, contra the psychologists, that depression is indeed a bio-medical phenomenon and can indeed respond to chemical intervention. The problem is that we just don't know yet what the ideal interventions are. Second, it suggests that these medications, imperfect though they surely are, do not function primarily as placebos, which is the claim often made by those opposed to psychiatric pharmacology. (Though this second point could be disputed, depending on the extent to which the placebo effect works on animals.

The other was the claim that depression "is not a single entity."  Depressions are different, and most likely have different physiological underpinnings, so it is no surprise that so many people fail to respond to specific medications. This is to be expected. We should also expect that this will not change:  As we learn more about depression we will become better at predicting which medications will be right for which patients. But it seems very unlikely that we will ever see one medications that treats all depressions.