The clinical profile of seasonal affective disorder (SAD), a recurring condition of winter depressions & summer remissions which we first described over a decade ago, has been widely corroborated, likewise, light therapy (LTX), which we first found to be an effective treatment for SAD, has become a mainstream psychiatric treatment. We have continued to study the clinical profile of SAD patients (PTS) with studies on: a) the concordance of seasonality & SAD in families; b) response characteristics of LTX: c) repetitive transcranial magnetic stimulation (rTMS); & d) subjects'subjective experiences as research participants & quality control evaluation of the SAD program. PTS report a higher prevalence of SAD & other affective disorders (AD) in their relatives than is found in the general population; hence, both Ad & seasonality (the tendency to be strongly affected by the seasons) are familial. We hypothesize that both seasonality & vulnerability to AD are inherited together. We predicated that the first-degree relatives of PTS with a history of AD will have higher seasonality scores than relatives without AD. WE have contacted 53 former PTS to develop a list of such first-degree relatives & data collection has begun. Formerly, we have adjusted the dose of LTX to achieve maximal clinical response, since our main goal was to compare depressed and non-depressed subjects regarding biological measures. This past year we administered a fixed LTX dose (10,000 lux 45 minutes morning & evening) with 16 PTS for two weeks to: 1)assess the efficacy of LTX as implemented & 2) relate LTX responsiveness to the biological measures under study. The SIGH-SAD, a measure of seasonal depression, was administered to assess LTX responsiveness. Data analysis is underway. rTMS applies a pulsating magnetic field to the brain to alter electrical activity. Study of depressed patients showed that left prefrontal rTMS improved mood but right-sided rTMS did not. In tandem with the LCS/NIMH, we explored whether rTMS may have application in SAD & non-seasonally depressed patients. We compared a single session of left-sided versus right-sided prefrontal rTMS in seven non-SAD depressed patients and two PTS. We will increase our sample of PTS to better understand how they respond to rTMS. We also asked about the subjective experiences of subjects that participated in our studies. Subjects reported that their experiences were primarily positive (e.g., increased understanding of SAD, valuing LTX). A most often reported complaint was discomfort related to procedures (e.g., venipuncture). In regards to informing subjects about studies, the subjects reported that a binder of SAD materials was the most useful source of information & that the official consent form was the least informative. We plan to make such assessments an ongoing component of the SAD program.
