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. 2025 Sep 2;25(1):851.
doi: 10.1186/s12888-025-07360-8.

Predictors of clinical trial discontinuation in trichotillomania: a secondary analysis of previous clinical trials

Trenton Lam  1 , Jon E Grant  2
Affiliations

Predictors of clinical trial discontinuation in trichotillomania: a secondary analysis of previous clinical trials

Trenton Lam et al. BMC Psychiatry. .

Abstract

Background: Participant discontinuation is a significant challenge in pharmacological trials for trichotillomania (hair-pulling disorder). Attrition in clinical trials reduces statistical power, introduces error, and potentially wastes financial and medical resources. Identifying predictors of discontinuation may help researchers enhance participant retention and improve study outcomes.

Methods: Data from five completed pharmacological trials for trichotillomania were aggregated, and participants were classified as either Discontinued or Completed. Differences in demographic and clinical variables between these groups were analyzed using a generalized linear mixed model.

Results: Of the 222 participants, 177 (80%) were categorized as the Completed group. Discontinued patients (20%) were more likely to have achieved higher levels of formal education and were more likely to have a history of depression.

Conclusions: This study is among the first to examine variables associated with discontinuation rates in trichotillomania trials. The results underscore the importance of addressing educational background and patient history of depression when assessing dropout risk. These findings can guide future research to better support participants at risk of discontinuing treatment.

Keywords: Clinical trial; Discontinuation; Dropout; Pharmacotherapy; Trichotillomania.

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Conflict of interest statement

Declarations. Ethics approval and consent to participate: The Institutional Review Board of the University of Chicago approved all of the previous studies and the consent statements. The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008. After complete description of the previous studies, participants all provided written informed consent. Consent for publication: Both authors consent for publication. Competing interests: Dr. Grant has received research grants from Janssen, Boehringer Ingelheim, and Biohaven Pharmaceuticals. He receives yearly compensation from Springer Publishing for acting as Editor-in-Chief of the Journal of Gambling Studies and has received royalties from Oxford University Press, American Psychiatric Publishing, Inc., Norton Press, and McGraw Hill. Mr. Lam reports no conflicts.

Figures

Fig. 1
Fig. 1
Estimated Dropout Means of Education
Fig. 2
Fig. 2
Estimated Dropout Means of History of Depression
See this image and copyright information in PMC

References

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