Recent Research Findings
Modern brain imaging technologies are revealing that in depression, neural circuits responsible for moods, thinking, sleep, appetite, and behavior fail to function properly, and that the regulation of critical neurotransmitters is impaired.Genetics research indicates that vulnerability to depression results from the influence of multiple genes acting together with environmental factors. Studies of brain chemistry, mechanisms of action of antidepressant medications, and the cognitive distortions and disturbed interpersonal relationships commonly associated with depression, continue to inform the development of new and better treatments.
The hormonal system that regulates the body's response to stress - the hypothalamic-pituitary-adrenal (HPA) axis - is overactive in many patients with depression. The hypothalamus, the brain region responsible for managing hormone release from glands throughout the body, increases production of a substance called corticotropin releasing factor (CRF) when a threat to physical or psychological well-being is detected.
Elevated levels and effects of CRF lead to increased hormone secretion by the pituitary and adrenal glands which prepares the body for defensive action. The body's responses include reduced appetite, decreased sex drive, and heightened alertness.
Research suggests that persistent overactivation of this hormonal system may lay the groundwork for depression. The elevated CRF levels detectable in depressed patients are reduced by treatment with antidepressant drugs, and this reduction corresponds to improvement in depressive symptoms.
