A 14 WEEK, RANDOMIZED, PLACEBO-CONTROLLED CROSS-OVER STUDY OF MULTILAYER RELEASE METHYLPHENIDATE CAPSULES (PRC-063) IN ADULT ADHD WITH AND WITHOUT ANXIETY DISORDER COMORBIDITY

Abstract

Background: Psychiatric comorbidity is the rule rather than the exception in adult Attention‐deficit Hyperactivity Disorder (ADHD) subjects, with the commonest being anxiety disorders [1]. Anxiety comorbidity has been shown to be associated with greater symptom severity, treatment resistance, and greater functional impairment in ADHD [2]. Stimulant medications have been proven to be effective in improving symptoms of ADHD, however, the data comes from subjects without comorbidity. This trial evaluated the benefit of stimulant medication in ADHD subjects with and without anxiety comorbidity. Aims & Objectives: To evaluate the efficacy and tolerability of multilayer (sustained) release methylphenidate capsules (PRC‐063) in adult patients with DSM‐5 ADHD with and without anxiety disorder comorbidity. Methods: This was a 14‐week, double‐blind, placebo‐controlled, flexible dose (25‐100mg/day), crossover study conducted at 2 sites. Adult ADHD subjects fulfilling DSM5 criteria (N=61) with or without an anxiety disorder comorbidity of panic disorder, agoraphobia, generalized anxiety or social anxiety disorder were included. After 1 week placebo run in, participants were randomized to PRC‐063 or placebo; the initial dose was 25mg/day and the dose was titrated up based on efficacy and tolerability to a maximum of 100mg/day over 4 weeks and the maximum dose was maintained for 2 more weeks (Phase 1). At week 7, all subjects were switched to placebo for 1 week before crossing over to the other condition (Phase 2). The ADHD Rating Scale (ADHD‐RS‐5) total score was the primary efficacy variable and response was defined as >or equal to 30% drop in ADHD‐RS‐5 plus a Clinical Global Impression‐Improvement (CGI‐I) score of