Antidepressant medication reverses increased sensitivity to light in depression: preliminary report.

1. Sensitivity to blue light was quantified using a Friedman Central Field Analyzer and the Dark Adaptation Threshold procedure. 2. Patients diagnosed as having a major depressive disorder using research diagnostic criteria had dark adaptation thresholds quantified after a 10 day drug wash out and again after antidepressant drug therapy. 3. Prior to drug treatment patients were significantly more sensitive to light than controls as measured by cone but not rod thresholds. 4. Following drug treatment both cone and rod thresholds were reduced in patients. In comparison to controls, drug treatment normalized cone threshold and reduced rod threshold in patients. 5. These data provide ophthalmological evidence for increased sensitivity to light in non medicated depressive disorder and a reduction in sensitivity following antidepressant drug therapy. 6. The possibility of altered retinal function and consequently the ability to perceive and use light for entrainment of circadian rhythm in affective disorder deserves further study.