Comorbidities, including diabetes and anxiety, are associated with cognitive dysfunction in multiple sclerosis (MS), according to a recent study. Their presence may contribute to the heterogeneous pattern of impairments seen across individuals and they may represent targets for improved management of cognitive symptoms. Participants completed a structured psychiatric interview, the Hospital Anxiety and Depression Scale (HADS), a comorbidity questionnaire, and cognitive testing including the Symbol Digit Modalities Test (SDMT), California Verbal Learning Test (CVLT-II), Brief Visuospatial Memory Test-Revised (BVMT-R), and verbal fluency. Test scores were converted to age-, sex- and education-adjusted z-scores. Researchers found:

• Of 111 participants, most were women (82.9%) with relapsing remitting MS (83.5%), of mean (SD) age 49.6 (12.7) years.
• Comorbidity was common; 22.7% participants had hypertension, 10.8% had diabetes, 9.9% had current major depression, and 9.9% had current anxiety disorders.
• Diabetes and anxiety disorder were associated with cognitive function overall.
• Diabetes was associated with lower BVMT-R (β=-1.18) and fluency (β=-0.63) z-scores.
• Anxiety was associated with lower SDMT (β=-1.07) z-scores.
• Elevated anxiety symptoms (HADS-A≥ 11) were associated with lower z-scores on the SDMT and CVLT-II.