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.