Objective: To explore the range of psychiatric symptoms in patients with multiple sclerosis (MS) and their association with neurological disability.
Method: Patients diagnosed with MS during 1998-2000 in Rogaland and Hordaland counties, western Norway, were included. Psychiatric symptoms were assessed by the Neuropsychiatric Inventory (NPI). Patients with systemic lupus erythematosus (SLE) served as controls.
Results: Eighty-six of 93 eligible MS patients were included, and 80% showed at least one psychiatric symptom. The most frequent symptoms were depression (59%), sleep disturbance (48%), irritability/emotional lability (42%), and apathy (31%). Depression was associated with higher disability score. MS patients showed significantly higher NPI irritability score (P = 0.002), appetite disturbance score (P < 0.001), and apathy score (P = 0.01) than SLE patients.
Conclusion: Neuropsychiatric symptoms occur frequently in patients with MS. Irritability and apathy are independent of disability and chronic disease and represent unique disease manifestations.