ReviewSocial cognition in Huntington's disease: A meta-analysis

- ToM and recognition of emotions from vocal and facial stimuli in Huntington's disease is impaired.
- Social cognitive deficits in Huntington's disease is already evident before the onset of motor symptoms.
- Illness progression is associated with decline in emotion recognition and ToM abilities.

Neurocognitive impairment in Huntington's disease (HD) frequently includes deficits in emotion recognition, and recent studies have also provided evidence for deficits in theory of mind (ToM). There have been conflicting reports regarding the extent of emotion recognition and ToM deficits before the onset of motor symptoms in HD. In this meta-analysis, ToM and emotion recognition performances of 2226HD or pre-manifest HD and 998 healthy controls were included in the meta-analysis. Meta-regression analyses were conducted to investigate the relationship between social cognition deficits and demographic, cognitive and clinical features in HD. HD patients were significantly less accurate than controls in ToM and across all emotions in response to both facial and vocal stimuli. ToM (d = 1.72) and recognition of negative emotions (d = 1.20-1.33), especially anger, disgust and fear (d = 1.26-1.52) were severely impaired. Pre-manifest HD was also associated with impairment in social cognition. The severity of emotion recognition impairment was significantly associated with disease burden, proximity of onset of motor symptoms and cognitive impairment. Social cognition impairments are potential biomarkers of disease onset and progression in HD.