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.