Characterizing the Placebo Response in Adults With ADHD. Issue 3 (February 2020)

• Record Type: Journal Article
• Authors: Ben-Sheetrit, Joseph; Peskin, Miriam; Newcorn, Jeffrey H.; Daniely, Yaron; Shbiro, Liat; Rotem, Ann; Weizman, Abraham; Manor, Iris
• Is Part Of: Journal of attention disorders. Volume 24:Issue 3(2020)
• Page Start: 425
• Page End: 433
• Publication Date: 2020-02
• Subjects: placebo -- nocebo -- adult ADHD -- nonstimulants; Attention-deficit hyperactivity disorder -- Periodicals; Attention -- Periodicals; 616.8589
• DOI: 10.1177/1087054718780328
• Languages: English
• ISSNs: 1087-0547

Abstract

Objective: Several ADHD pharmacological trials reported high placebo response (PR) rates. This study aims to characterize the PR in adult ADHD.Method : A retrospective cohort analysis of the placebo arm (140 adults with ADHD, 18-55 yrs, M:F 46.4%-53.6%) of a 6-week randomized, multicenter, double-blind metadoxine study, using Conners' Adult ADHD Rating Scale (CAARS) and the Adult ADHD Self-Report Scale (ASRS), was conducted.Results : Pre–post changes in placebo-treated adults were significant for both the CAARS and ASRS, F (2.9, 404.5) = 61.2, p < .00001, F (2.8, 383.0) = 43.1, p < .00001, respectively. Less than half of the participants had a PR which began early in treatment and persisted; almost 50% had a variable, inconsistent PR.Conclusion : In the current sample, PR in adult ADHD was prominent on both symptom scales and the investigator–rater instrument. Therefore, using investigator ratings as a primary endpoint does not necessarily attenuate PR. Of note, about half of the PR is variable, suggesting unreliable determination of efficacy.