Possible role of brain thyroid hormones in the effects of bright light on mood and behavior

Considerable evidence suggests that light may significantly affect the meta bolism of cerebral thyroid hormones. Changes in the brain thyroid economy, independent of peripheral changes in thyroid status, may produce considerab le behavioral effects. Exposure to bright light affects the mood and behavi or of healthy people and individuals with psychiatric disorders. The author suggests that the effects of bright light on mood and behavior may be part ly mediated by light-induced changes in the metabolism of brain thyroid hor mones. (C) 2001 Harcourt Publishers Ltd.