BRIGHT LIGHT THERAPY STABILIZES THE ANTIDEPRESSANT EFFECT OF PARTIAL SLEEP-DEPRIVATION

Partial sleep deprivation (PSD) results in a pronounced decrease of de pressive symptoms in the majority of patients with major depressive di sorder, Generally this acute antidepressant effect is not stable, rela pse usually occurs after one night of recovery sleep, We therefore stu died whether light therapy, beginning in the morning after PSD, is abl e to prevent the relapse after sleep deprivation, using a controlled, balanced parallel design, All patients received an antidepressant medi cation, which was kept constant before and during the study period Fou rteen of 20 patients (70%) showed a reduction of at least 40% in the H amilton Depression Rating Scale (HDRS) in the morning after PSD and we re classified as PSD responders, Responders as well as nonresponders w ere randomly assigned to receive either bright light (BL/3000 lux) or dim light (DL/100 lux) therapy during the following 6 days after PSD. In the responder group BL therapy prevented significantly (p = 0.005) the relapse after the next night of sleep and prolonged significantly (p = 0.011) the antidepressant effects of PSD up to 7 days, In contras t, patients in the DL condition relapsed after the recovery night and showed no further improvement of the depressive syndrome after I week of DL therapy, PSD nonresponders did not benefit from light treatment, These findings indicate that BL therapy might be efficacious to preve nt relapse after PSD,