Brain serotonin levels as a predictor of suicide has been the subject of intense research scrutiny over the past several years, with scientists trying to find easily accessible markers so that the neurotransmitter's levels might someday be readily measured in clinical settings.
Dopamine plays an important role in controlling movement, emotion and cognition. Dopaminergic dysfunction has been implicated in the pathophysiology of schizophrenia, mood disorders, attention-deficit disorder, Tourette's syndrome, substance dependency, tardive dyskinesia, Parkinson's disease and other disorders.
The gloom of winter, more often a literary theme than a medical topic, is a biological reality for an estimated 10 million Americans who suffer from seasonal affective disorder (SAD). For some, however, the depression ushered in by the dark days of winter can be treated simply and with rapid results with 30 minutes to two hours of bright-light therapy per day for a few weeks.
