Emotion Evaluation and Social Inference Impairments in Huntington's Disease

Background: Huntington's disease (HD) is an inherited neurodegenerative disorder characterised by motor, cognitive and neuropsychiatric symptoms. Recent research has established that individuals with HD display reduced discrimination of emotional facial expressions and impaired higher-order social cognitive skills, including 'theory of mind'. Objective: This study aimed to further characterise the emotion evaluation and theory of mind deficits in HD in an ecologically-valid context, and determine their impact on socially-relevant functional abilities. Methods: A sample of 17 HD participants and 24 healthy controls were assessed using The Awareness of Social Inference Test (TASIT), together with additional self-and informant rated measures of cognition, social communication, empathy and neuropsychiatric symptoms. Results: Participants with HD showed significant difficulties in evaluating negative emotions, and understanding sincere, sarcastic and 'paradoxical sarcastic' statements, compared with controls. The ability to evaluate positive emotions was negatively correlated with behavioural problems, but no other clinical, behavioural or communication measures correlated significantly with TASIT subscales. Conclusions: These findings suggest that social cognitive difficulties in symptomatic HD may be underpinned by more generalised impairments, related to deciphering social exchanges, as opposed to a selective theory of mind deficit. Such difficulties have the potential to place significant strain on interpersonal relationships, and thus warrant thorough clinical assessment, using ecologically-valid tools, to promote early detection and development of person-centred interventions.