Psychiatry International · Published 2026-08-04 · DOI 10.3390/psychiatryint7040172
Selina Kit Yi Chan, Kelvin K. F. Tsoi, Terry Cheuk Fung Yip, Vivien Wei Jun Liew, Wai Kwong Tang
<b>Background:</b> This study aimed to investigate whether individuals with trichotillomania (TTM) are at a higher risk of engaging in self-harm behaviors compared to those without TTM. <b>Methods:</b> In this matched cohort study, we analyzed electronic health records of all patients admitted to public hospitals in Hong Kong from 1 January 1993 to 31 December 2022. We identified a TTM cohort of 285 patients and a comparison cohort of 285 individuals. All participants were followed up until they received a diagnosis of self-harm, died from other causes, or until the end of 2023, whichever came first. To assess the risk of self-harm following TTM onset, Cox proportional hazards regression models were applied. <b>Results:</b> Throughout the 30-year study period, the number of individuals who exhibited self-harm behavior in the TTM and comparison groups was 8 (2.8%) and 8 (2.8%), respectively. The TTM and comparison groups had similar proportions of subjects who inflicted self-harm (χ<sup>2</sup> = 0.00, <i>p</i> = 0.977). The incidence of self-harm was 26.00 and 26.92 per 10,000 person-years in the TTM and comparison groups, respectively. Compared with the comparison group, the adjusted hazard ratio for self-harm in the TTM group was 1.44 (95% confidence interval, 0.45–4.61). <b>Conclusions:</b> TTM is not associated with an increased risk of self-harm. Future research is necessary to replicate our findings and more fully elucidate the potential unique risk factors for self-harm in these patients.
Abstract from DOAJ. Public domain (CC0 1.0).
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Chan, S., Tsoi, K., Yip, T., et al. (2026). Risk of Self-Harm in Patients with Trichotillomania: A Population-Based Cohort Study. Psychiatry International. https://doi.org/10.3390/psychiatryint7040172