Cognitive but not affective theory of mind deficits in mild relapsing-remitting multiple sclerosis

OBJECTIVE:: We studied theory of mind (ToM) in patients with mild relapsing-remitting multiple sclerosis (MS), seeking possible dissociations between its 2 components: cognitive ToM (the ability to infer others' intentions) and affective ToM (the ability to infer others' emotional states). We analyzed the relationship of ToM to executive function, depression, and fatigue. BACKGROUND:: Dissociations between cognitive and affective ToM have been found in several neurologic and neuropsychiatric diseases. Most ToM studies in patients with MS have shown general ToM deficits but have not analyzed the cognitive and affective aspects individually. METHODS:: We used the Faux Pas test of ToM and tests of executive function to assess 18 patients with mild relapsing-remitting MS and 16 control participants. RESULTS:: Our patients showed deficits in cognitive ToM, but their affective ToM seemed to be spared. Their cognitive ToM deficits were not related to executive dysfunction, depression, or fatigue. CONCLUSIONS:: Our study is the first differential analysis showing cognitive but not affective ToM deficits in mild relapsing-remitting MS. Further research is needed to determine the exact nature and the real impact of these deficits, and to establish their relationship with the neuropathology and progression of MS.