Cognitive and affective theory of mind in Korsakoff's syndrome.

OBJECTIVE: Korsakoff's syndrome (KS) is a chronic neuropsychiatric disorder characterised by severe anterograde amnesia and executive deficits. Theory of Mind (ToM) is the capacity to represent others' mental states such as their knowledge, thoughts, feelings, beliefs, and intentions in order to explain and predict their behaviour. Surprisingly this topic has received hardly any attention in research on KS, although the severity of behavioural problems in KS suggest possible ToM difficulties. The aim of the present study was therefore to assess whether cognitive and affective ToM are impaired in patients with KS.

METHODS: We examined 21 KS patients and 21 age- and gender-matched healthy controls on three standardised tests that assess cognitive and affective ToM, including the subtests of the mini-Social Cognition and Emotional Assessment battery and a specialised version of the Sally-Anne Test.

RESULTS: KS patients showed largely impaired cognitive and affective ToM compared to healthy controls, as reflected in large effect sizes on both cognitive and affective ToM tests. Executive deficits explained problems in emotion recognition, but not other ToM aspects.

CONCLUSION: KS patients have large impairments in both cognitive and affective aspects of social cognition. Their ability to recognise emotions, take the perspective of others, and understand socially awkward situations is vastly compromised. The impairments in ToM functioning are to a large degree functionally discrepant from executive disorders that are commonly present in KS. This study therefore highlights the importance to properly index ToM functioning in neuropsychological assessments for individuals with a possible KS diagnosis.