Carlson, Matthew David

526 Background: Antidepressants do not adequately alleviate all HFs. Based on placebo-controlled data demonstrating that GABA is an alternative therapy for HFs, this trial was initiated to test whether the combination of an antidepressant and GABA was better than GABA alone in PTS with inadequate HF control on an antidepressant alone. Methods: Eligible PTS on antidepressants with bothersome HFs were randomized to two groups. PTS kept a daily HF diary during a baseline wk (while continuing their antidepressant). Following the baseline wk, all PTS were given GABA 300 mg at hs for 3 days, then BID for 3 days, and then TID for 22 days. One group continued their antidepressant while the other group was weaned off it over several days. PTS continued a daily HF diary during this 4-wk period. Efficacy was measured using the mean daily HF number and score; the latter measured by assigning points (1–4, for mild to very severe) to each HF and then adding the points for a given time. The study design provided 80% power to detect a difference in the changes from baseline at 4 wks between the two groups of 1.2 HFs/day, or 3 points/day in HF scores. Results: 115 PTS were randomized and given GABA. PTS continuing their antidepressant reported a 48% mean reduction in HF score after 4 wks, vs 49% for PTS stopping it (p=0.97). Mean HF numbers were reduced 50% and 47%, respectively (p=0.54). 16 other symptoms and quality of life items were measured by PT-completed weekly questionnaires, with the only suggestive changes from baseline between the two arms being more mood troubles after 2 wks of treatment (p=0.06) and more nervousness after 4 wks of treatment (p=0.01) in PTS stopping their antidepressant. Also, a mild temporary increase in dizziness after 1 wk of treatment was observed in the same group (p=0.08) suggestive of an antidepressant withdrawal reaction. Conclusion: This trial failed to provide any evidence that the combination of GABA and an antidepressant decreased HFs any more than did GABA alone in PTS who had inadequate HF control with an antidepressant alone. The 50% reduction in HFs in both arms is commensurate with the efficacy of GABA delineated in other published reports. No significant financial relationships to disclose.