Exposure to light during the night reduces plasma melatonin levels. A
previous study showed that, in response to light, nighttime plasma
melatonin levels fell twice as much in a group of acutely ill manic-
depressive patients as in a group of normal subjects. The present study
compares 11 euthymic manic-depressive patients not taking medications with
24 age- and sex-matched normal subjects. Melatonin levels in these patients
also fell twice as much as the levels of the normal subjects, suggesting
that supersensitivity to light may be a trait marker for bipolar affective
disorder.
Abstract Teaser