THYROID-FUNCTION BEFORE AND AFTER 4-WEEK LIGHT TREATMENT IN WINTER DEPRESSIVES AND CONTROLS

Thyroid function in patients in a current major depressive episode dur ing the course of recurrent major mood disorder with seasonal pattern according to DSM-IIIR was compared to that of controls before and afte r 4 weeks' light treatment, and to that of controls at baseline and af ter 4 weeks' of arising early without exposure to bright light. No con sistent abnormalities in thyroxine, free thyroxine index, triiodothyro ine, reverse triiodothyronine, thyrotropin, thyrotropin response to TR H infusion, or thyroid autoantibodies were seen in depressives at base line. No differences in these parameters were seen at baseline between depressives and controls. No intergroup differences were seen with tr eatment, although reverse T3 decreased significantly during the protoc ol in all groups. These data do not support the hypothesis that the th yroid axis plays a role in the pathogenesis of winter depressive sympt oms or their response to light treatment.