DOPAMINE AND CIRCADIAN-RHYTHMS IN SEASONAL AFFECTIVE-DISORDER

In seasonal affective disorder, there is evidence of both increased an d decreased dopaminergic transmission in the central nervous system. B right light treatment appears to normalize these abnormalities among t he patients. Dopamine is suggested to have a direct effect on heat los s via the vascular system, in addition to its capability of resetting the circadian system by changes in both heat production and heat loss. Therefore, impaired dopamine availability may result in a decreased h eat loss response to an endogenous thermal challenge as well as abnorm alities in the generation of circadian rhythms in some patients with s easonal affective disorder.