Located toward the front of the brain, the structure has been implicated in depression and, intriguingly, altruistic behavior, and is thought to help negotiate between emotion and cognition, impulse and calculation.
In addition, TNF has been implicated in depression and irritable bowel disease [18, 19], recognized as migraine comorbidities [20, 21].
And their brains showed signs of their emotional pain, with heightened activity in the parahippocampus and other emotion-related areas that have been implicated in depression.
Although serotonin has been implicated in depression, obsessive-compulsive behaviors, eating disorders, and aggressiveness, the brain chemical dopamine--which is part of the brain's reward system--has gotten almost all of the attention in addiction studies, White says.
Low BDNF has also been implicated in depression as well as impaired cognitive functions such as learning and memory.
Why bright light has an anti-depressant effect is not known, but the researchers said one possibility is that bright light may suppress secretion of a hormone called melatonin that is among many that have been implicated in depression.
Prenatal glucocorticoid excess has been implicated in depression-like behaviors (Bale 2005), hypertension (Levitt et al. 1996), and hypothamalic-pituitary-adrenal axis dysregulation (Levy and Tasker 2012) in adulthood.
Adult neurogenesis is implicated in depression and Alzheimer's disease, both of which involve hippocampal shrinkage.
Those have already yielded evidence that in the year after a concussion, scanned participants showed evidence of shrinkage in a region of the brain -- the anterior cingulate gyrus -- that's implicated in depression.
