In multiple sclerosis (MS), the prevalence of alexithymia, defined as an inability to identify and describe emotions, is close to 50% but the prevalence of this symptom in clinically isolated syndrome (CIS) is unknown. Characterizing alexithymia at an early stage of the disease can help to clarify psychobehavioural disturbances in CIS patients.

Forty CIS patients, who fulfilled the MRI criteria for dissemination in space, were matched with 40 healthy subjects. They completed self-assessment scales for alexithymia, depression, anxiety, apathy and empathy. Cognitive functions were assessed using a battery of neuropsychological tests.

The mean delay (± standard deviation) between the occurrence of CIS and inclusion in the study was 3.9 (2.8) months. The frequency of alexithymia was higher in CIS patients than in controls, with a prevalence of 42% (P<0.0001). Alexithymia correlated with anxiety and depression but not with cognition. Alexithymia was dependent only on depression (P=0.003).

Alexithymia, characterized by difficulty identifying feelings, is present in patients in the early stage of MS, and seems to be strongly associated with depression. Difficulty in social interaction could be a risk of future affective disorders.