The burden of mental comorbidity in multiple sclerosis: frequent, underdiagnosed, and undertreated

BACKGROUND: Mental comorbidity is common in multiple sclerosis (MS), but some studies suggest that mental comorbidity may be underrecognized and undertreated. OBJECTIVE: Using the North American Research Committee on MS Registry, we assessed the frequency of mental comorbidities in MS and sociodemographic characteristics associated with diagnosis and treatment of depression. METHODS: We queried participants regarding depression, anxiety, bipolar disorder, and schizophrenia. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CESD) ; a score>or=21 indicated probable major depression. RESULTS: Mental comorbidity affected 4264 (48%) responders; depression most frequently (4012, 46%). Among participants not reporting mental comorbidity, 751 (16. 2%) had CESD scores>or=21 suggesting undiagnosed depression. Lower socioeconomic status was associated with increased odds of depression (Income 15, 000-30, 000 vs >100, 000 OR 1. 34; 1. 11-1. 62), undiagnosed depression (Income 15, 000-30, 000 vs >100, 000 OR 1. 52; 1. 08-2. 13), and untreated depression (<high school vs postgraduate degree OR 3. 13; 1. 65-5. 99). CONCLUSIONS: Mental comorbidity remains underdiagnosed and undertreated in MS. Patients of lower socioeconomic status bear a disproportionate share of the burden of depression.