F057 Affective and cognitive components of theory of mind in Huntington’s disease: yoni task performance in early and mid-disease stages

Introduction Theory of mind (ToM) is the ability to predict another’s behaviour by inferring their mental and emotional states. Impairments to ToM have been reported in Huntington’s disease (HD) [1]. Aims To investigate ToM dysfunction in early and mid-HD. Methods Nine Shoulson’s stage I (TFC 11–13) HD patients, 10 stage II (TFC 7–10) HD patients [2], and 22 healthy controls (HC) were recruited. All participants completed the computerised Yoni task [3], a ToM assessment that evaluates cognitive and affective dimensions at two levels of difficulty (first- and second-order inference). Control items are also included to evaluate general understanding of the task. Results Stage I patients manifested no significant difference on first-level ToM items compared to HC, whereas a difference emerged for second-level ToM items, particularly cognitive items. The performance of this subgroup of HD for control items was comparable to HC. Stage II patients showed poorer performance on both cognitive and affective ToM items at both difficulty levels compared to HC and HD stage I patients figure 1. Discussion Cognitive ToM involving second-level inference is impaired in the early stages of HD, whereas both cognitive and affective components are altered by the mid-stage, with the greatest dysfunction to cognitive second-level ToM, probably due to more severe cortical damage. In both HD subgroups, the affective component of ToM is better preserved. These social cognition problems point to the urgency of developing rehabilitative interventions in HD to strengthen and nurture successful interpersonal relationships, with potential benefits for individuals with HD and their families.