A CONTROLLED TRIAL OF LEVODOPA PLUS CARBIDOPA IN THE TREATMENT OF WINTER SEASONAL AFFECTIVE-DISORDER - A TEST OF THE DOPAMINE HYPOTHESIS

The objectives of this study were to test the hypothesis that a dopami nergic deficiency plays a role in the pathogenesis of winter seasonal affective disorder (SAD) and to test the efficacy of levodopa plus car bidopa as a treatment for SAD. Two weeks of double-blind placebo washo ut were followed by random assignment to parallel treatments for 2 wee ks with levodopa and carbidopa versus placebo. Observations were made during weekly outpatient visits. All subjects met criteria for SAD. Fi fty patients entered the study. Twenty-four were significantly depress ed after the washout period and were randomly assigned to medication o r placebo. Twenty-three completed the study. Twelve patients received placebo capsules four times a day during the 2-week drug comparison pe riod. On an identical schedule, 11 patients received capsules containi ng levodopa (up to 7 mg/kg per day by the end of the second week) and carbidopa (100 mg/day). Twenty-one item Hamilton Rating Scale for Depr ession scores were used to determine antidepressant efficacy. No diffe rences were found in the rates of response. There is no evidence to su pport the use of levodopa for the treatment of SAD patients in general . A model of systemic dopaminergic deficiency does not readily explain the pathology of SAD.