Let s go to the break now, and then we will start taking your telephone calls when we come back. Back in a minute. Sleep disturbances are common in people with either mania or depression. Specifically, the difference between daytime and nighttime levels was much smaller in SAD patients. Together, these observations would suggest a role for melatonin in various forms of depression.
Artificial light can also impact blood melatonin levels.
Appropriately timed light therapy is reported to be efficacious in the treatment of seasonal affective disorder. Blood melatonin appears to respond to other environmental cues such as seasonal and temperature changes. The details of environmental influences on melatonin production and blood levels in humans need much further investigation before the complete picture will unfold. Well, if so, you are not alone. This condition, SAD or seasonal affective disorder, affects between 5 to 25 million Americans.