A TABLET-BASED ATTENTIONAL COGNITIVE BIAS MODIFICATION INTERVENTION FOR POSITIVE EMOTION PROCESSING IN MAJOR DEPRESSIVE DISORDER: A DOUBLE-BLIND RANDOMIZED CONTROLLED TRIAL

Patients with Major Depressive Disorder (MDD) exhibit biased information processing. This study investigates the clinical and neural efficacy of a cognitive bias modification (CBM) training in patients and healthy control subjects (HCS) fostering processing of positive emotion stimuli. In a double-blind randomized controlled trial (DRKS00029756), participants were randomized to positive training (PT) or control training (CT). Participants underwent 10 tablet-based dot-probe sessions over 14 days. PT aimed to implicitly redirect attention toward positive stimuli to improve depressive symptoms. Primary outcome was pre and post training EEG derived Early Posterior Negativity (EPN) investigating neural sensitivity towards positive stimuli. Secondary clinical outcomes were changes in depression symptom severity. 240 participants were included (119 MDD; 121 HCS). 62 MDD and 61 HCS underwent ET, and 59 MDD and 58 HCS received CT. In MDD, EPN to positive high arousal stimuli revealed an interaction between time (pre/post) and training (PT/CT), F(1,97) = 5·017, p < ·05, η² = ·049. EPN shifted towards negativity in PT, while it shifted towards positivity in CT. In HCS, EPN amplitudes increased towards negativity in both conditions without interaction effect. Depression symptom severity decreased in patients, with reductions from pre to post and from pre to follow-up. No severe adverse events occurred. CBM positivity training showed treatment specific neural efficacy in MDD patients and is proposed as a possible non-pharmacological treatment option focusing on pre-attentive positive emotion processing. Follow-up EEG assessment and higher training intensity may be needed to understand translations of neural changes into clinical improvement.