This placebo-controlled, double-blind, 1-year pilot study aimed at investigating possible clinical advantages of combining initial light therapy with the selective serotonin reuptake inhibitor (SSRI) citalopram as well as the effects of continuous long-term administration of this drug in patients with seasonal affective disorder (SAD). Eight physically healthy women who met the DSM-III-R criteria for SAD were included in the study. Four women were randomized to the citalopram group receiving 40 mg citalopram daily from the first of 10 light treatment days and throughout the 1-year study. The remaining four women were allocated to the placebo group using the same double-blind repeated measures design. The clinical outcome was measured by using three versions of the Comprehensive Psychopathological Rating Scale (CPRS) and Visual Analog Scales (VAS), respectively. Taking the initial rating scores into account in covariance analyses, no statistically significant group difference was found during the light treatment period. However, during the follow-up period the full version of the CPRS and the self-rating version of CPRS and the VAS-scales for global condition and depressed mood were statistically significantly lower in the citalopram group compared with the placebo group. Thus, in this small but carefully observed sample of SAD-patients combining initial light therapy and long-term citalopram treatment was clinically more effective over time than the placebo combination. Our findings support the notion that light therapy with concomitant and continued SSRI (citalopram) treatment is a useful strategy to achieve beneficial long-term effects in patients with the SAD syndrome.