Platelet paroxetine binding and light therapy in winter depression

The effect of light therapy on serotonin uptake capacity in patients suffering from winter depressions (seasonal affective disorders) was examined indirectly by using [ 3H]paroxetine binding to determine the number of platelet serotonin transporters. In patients who responded to light therapy the number of platelet serotonin transporters decreased significantly following treatment. In contrast, patients who did not respond to light therapy were found to have a relatively low number of serotonin transporters prior to treatment, and the number did not change significantly following treatment.