Theory of Mind in Parkinson's disease

The ability to infer other people's mental states (i.e. Theory of Mind, ToM) is a major topic of interest in various neurological and psychiatric disorders. However, it is only recently that there has been an assessment of cognitive and affective components of ToM ability in neurodegenerative disorders. In this review, we examine studies investigating the ToM ability in Parkinson's disease (PD). Taken together, these studies provide preliminary evidence that ToM difficulties may occur in PD patients. In particular, these difficulties principally involve the cognitive component of ToM in the early stages of the disease. The spatio-temporal progression of dopamine depletion supports the hypothesis that the affective component may only be affected in the advanced stages of the disease. The relationships between executive functioning, dopaminergic therapies, and ToM in PD as well as the relationships between frontostriatal circuits and ToM processing are discussed.

Research highlights
► Theory of Mind (ToM) is the ability to infer other people's mental states.
► We review studies investigating the ToM ability in Parkinson's disease (PD).
► We found preliminary evidence that ToM difficulties may occur in PD patients.
► These difficulties involve the cognitive component of ToM in the early stages of PD.
► The affective component of ToM may only be affected in the advanced stages of PD.