306. EMOTIONAL FACES MEMORY TASK PERFORMANCE AND CLINICAL OUTCOMES FOR THE NOVEL PRESCRIPTION DIGITAL THERAPEUTIC, CT-152

Abstract Background CT-152 received US Food and Drug Administration 510(k)-clearance as a prescription digital therapeutic adjunct to antidepressant medication in patients with major depressive disorder (MDD). CT-152 provides a novel mechanism of action through use of the Emotional Faces Memory Task (EFMT). Aims & Objectives This post hoc analysis correlated change in the Montgomery-Åsberg Depression Rating Scale (MADRS) score change from baseline to the end of the intervention and extension periods with participants' memory-task performance. Method In the Phase 3 Mirai trial (6-week intervention/4-week extension periods), adults (22–64 years) with MDD and inadequate response to current antidepressant medication were randomly assigned to CT-152 or sham smartphone apps. CT-152 includes EFMT and CBT-based lessons; sham includes a time/attention/expectation-matched memory-task. EFMT is a N-back task that requires participants to recall sequences of facial emotions displayed N-steps prior, where N-values increased as a function of performance accuracy. This post hoc analysis correlated change in MADRS scores from baseline to weeks 6 and 10 with participants' memory-task performance (EFMT or sham). Results Participants (N=386) were randomly assigned to CT-152 (n=194) or sham (n=192). EFMT performance was measured by maximum N-back level achieved, rounds completed at N-back>1, and EFMT sessions completed. EFMT performance was correlated with MADRS outcomes; for example, the number of rounds attained at N-back>1 predicted both Week 6 and 10 MADRS outcomes. Achieving N-back=3 during the first EFMT was also predictive of MADRS improvement at Week 6; however, achieving the difficulty threshold N-back≥5 overall was not correlated with MADRS outcomes. Importantly, no relationship was observed between sham-app memory-task performance and MADRS outcomes. Discussion & Conclusions CT-152 EFMT, but not sham-app performance, was correlated with MADRS improvements, highlighting EFMT therapeutic effects even for participants who did not achieve more difficult N-back thresholds.