Pathophysiology of Major Depression

Pathophysiology of Major Depression

There has been a marked shift in the last decade in our under-standing of the pathophysiology of major depression. In addition to the older idea that a deficit in function or amount of monoam-ines (the monoamine hypothesis) is central to the biology of depression, there is evidence that neurotrophic and endocrine fac-tors play a major role (the neurotrophic hypothesis). Histologic studies, structural and functional brain imaging research, genetic findings, and steroid research all suggest a complex pathophysiol-ogy for MDD with important implications for drug treatment.