Beyond its hallmark motor symptoms, Huntington’s disease (HD) involves early and progressive disruption of cognitive and psychiatric functions critical for social interaction. Theory of Mind (ToM), the ability to infer one’s own and others’ mental states, is particularly vulnerable in HD. The present study investigated cognitive and affective ToM across disease stages and their association with neuropsychiatric symptoms.

A total of 24 HD patients (12 stage I, 12 stage II) and 24 healthy controls completed the Yoni Task, assessing cognitive and affective ToM. Neuropsychiatric symptoms were evaluated using the Problem Behaviors Assessment—short version, and quality of life with the 12-item Short Form Health Survey.

Cognitive ToM was significantly impaired already in stage I HD compared to controls (mean accuracy: 68.5% vs. 87.6%, p = 0.004), while affective ToM was relatively preserved (76.4% vs. 86.2%, p = 0.095). Stage II patients showed marked deficits in both domains (cognitive ToM: 46.3%; affective ToM: 52.3%), performing significantly worse than controls (p < 0.001). Total ToM performance declined progressively across stages (p < 0.001). Lower affective ToM scores were associated with greater irritability/aggression (ρ = –0.40, p = 0.049), obsessive–compulsive symptoms (ρ = –0.51, p = 0.015), and poorer self-reported physical functioning (ρ = 0.42, p = 0.049).

ToM impairments in HD are stage-dependent, with early cognitive deficits and later involvement of affective processes. Decline in ToM performance is clinically meaningful and associated with neuropsychiatric symptoms, particularly irritability. ToM assessment may therefore provide a sensitive marker of socio-cognitive dysfunction and disease progression in HD.