Prediction of treatment response and the effect of independent component neurofeedback in obsessive-compulsive disorder: a randomized, sham-controlled, and double-blind study

Abstract

International audienceAIMS: The goal of this study was to assess the effect of independent component neurofeedback (NFB) on EEG and clinical symptoms in patients with obsessive-compulsive disorder (OCD). Subsequently we explored predictors of treatment response and EEG correlates of clinical symptoms. METHODS: In a randomized, double blind and parallel design 20 in-patients with OCD underwent 25 sessions of NFB or sham feedback (SFB). NFB aimed at reducing EEG activity in an independent component previously reported abnormal in this diagnosis. Resting state EEG recorded before and after the treatment was analysed to assess its post-treatment changes, relationships with clinical symptoms and treatment response. RESULTS: Overall, clinical improvement in OCD patients was not accompanied by EEG change as assessed by standardized low-resolution electromagnetic tomography and normative independent component analysis. Pre- to post-treatment comparison of the trained component and frequency did not yield significant results, however, in the NFB group, the nominal values at the down-trained frequency were lower after treatment. The NFB group showed significantly higher percentage reduction of compulsions compared to the SFB group (p=0.015). Pre-treatment higher amount of delta (1 - 6 Hz) and low alpha oscillations as well as lower amount of high beta activity predicted a worse treatment outcome. Source localization of these delta and high beta oscillations corresponded with previous EEG resting state findings in OCD patients compared to healthy controls. CONCLUSION: Independent component NFB in OCD proved useful in percentage improvement of compulsions. Based on our correlation analyses we hypothesize that we targeted a network related to treatment resistance