Accepted: 19 December 2020
First Online: 8 January 2021
Compliance with Ethical Standards
: Dr. Ricketts has received research support from the BFRB Precision Medicine Initiative granted by the TLC Foundation for Body-Focused Repetitive Behaviors, and National Institute of Mental Health (NIMH). Dr. Snorrason, Dr. Ólafsson, Ms. Sigurvinsdottir and Mr. Mathew declare that they have no conflict of interest. Dr. Woods has received royalties from Oxford University Press and Springer Press. Dr. Lee has received research support from the TLC Foundation for Body-Focused Repetitive Behaviors, and the Tourette Association of America.
: Study 1 approval was granted by the National Bioethics Committee of Iceland and study 2 approval by the University of Wisconsin-Milwaukee Institutional Review Board. These studies were performed in line with the principles of the Declaration of Helsinki.
: Informed consent was obtained from all participants included in these studies.
: No animal studies were carried out by the authors for this article.