Placebo response in trichotillomania.

Michael van Ameringen,Jon E. Grant,Nancy J. Keuthen,Suck W. Kim,Darin D. Dougherty,Sarah A. Redden,Brian L. Odlaug,Samuel R. Chamberlain

doi:10.1097/yic.0000000000000185

Abstract

Trichotillomania is a functionally impairing, often overlooked disorder with no Food and Drug Administration-approved medications indicated for its treatment. The ability of clinical trials to detect the beneficial effects of pharmacologic treatment in trichotillomania has been hampered by the high placebo response rate. Very little is known about baseline demographic and clinical characteristics that may be predictive of placebo response in such patients. Overall, 104 participants assigned to placebo were pooled from five double-blind trials conducted at three sites in the USA and Canada. Participants were classified as placebo responders or nonresponders on the basis of a cutoff of a 35% reduction in symptom severity on the Massachusetts General Hospital Hair Pulling Scale. Baseline group differences were characterized using t-tests and equivalent nonparametric tests as appropriate. Thirty-one percent of individuals assigned to placebo treatment showed a significant clinical response to placebo. Placebo responders (n=32) and nonresponders (n=72) did not differ significantly on any demographic or clinical variable. Predictors of placebo response for trichotillomania remain elusive and do not appear to be similar to those reported for other mental health disorders.

Highlights

Trichotillomania (TTM) is a potentially disabling, underrecognized condition in which individuals repeatedly pull out their hair, leading to hair loss
31.4% of participants assigned to placebo improved at least 35% on the Massachusetts General Hospital (MGH)-HPS during placebo treatment
Active treatment responders completed significantly more study weeks than placebo responders and had a marginally higher rate of obsessive-compulsive disorder (OCD) ( OCD was uncommon in both groups)

Summary

Introduction

Trichotillomania (TTM) is a potentially disabling, underrecognized condition in which individuals repeatedly pull out their hair, leading to hair loss. Psychosocial problems are common among individuals with TTM and may include significantly reduced quality of life, lowered selfesteem, and impaired social functioning (Diefenbach et al, 2005; Houghton et al, 2016; Grant and Chamberlain, 2016). Most of the double-blind, placebo-controlled pharmacological studies of TTM have failed to separate symptomatic changes significantly from placebo. The present study seeks to overcome this limitation by using a relatively large dataset that combines participants from five double-blind, placebocontrolled pharmacological trials in TTM conducted in the USA and Canada (Dougherty et al, 2006; Grant et al, 2009, 2014; Van Ameringen et al, 2010; Leppink et al, 2017)

Methods

Results

Conclusion