Theory of mind in trichotillomania: A cross-sectional comparison with healthy controls

Theory of mind (ToM) is the ability to make correct inferences from one's own or another person's mental states, such as thoughts, beliefs, desires, and intentions. Although there are a limited number of studies in the literature examining the social cognitive functions of patients with trichotillomania (TTM), no studies have evaluated ToM. This study aimed to compare the ToM skills of patients with TTM and healthy controls.

The study included 40 patients who were diagnosed as having TTM according to DSM-5 criteria and 40 healthy controls matched for age, education, and sex. A Sociodemographic and Clinical Data Form, the Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Massachusetts General Hospital Hairpulling Scale (MGH-HPS), Toronto Alexithymia Scale (TAS-20), Reading the Mind in the Eyes Test (RMET), and the Dokuz-Eylül Theory of Mind Scale (DEToMS) were administered to the participants.

Patients with TTM performed statistically significantly worse than healthy controls in terms of ToM, metaphor concept, empathic understanding, and faux pas scores. No statistically significant difference was found between the groups in terms of first-degree false belief, second-degree false belief, and irony concept scores. Depression, anxiety, and alexithymia scores of patients with TTM were statistically significantly higher than the control group. No significant correlation was found between ToM tests and anxiety, depression, alexithymia, disease severity, and disease duration in the TTM group.

Our findings show that there is an impairment in ToM skills in patients with TTM and that this impairment is independent of clinical features. Studies with larger samples are needed on this subject.