Psychiatric co-morbidity in multiple sclerosis: The risk of depression and anxiety before and after MS diagnosis

Background: Studies of depression and anxiety in multiple sclerosis (MS) patients have reported higher rates in MS patients than the general population. Objective: To estimate the risk of depression and anxiety and the use of tricyclic antidepressant and selective serotonin reuptake inhibitors (SSRI) prescriptions, in the pre-diagnostic and the post-diagnostic period of MS compared to the background population. Methods: A cohort of 5084 MS patients was included and matched with a control population of 24,771 persons linked to nationwide registers. Logistic regression analyses were performed estimating odds ratios (OR). Results: In the pre-diagnostic period, the OR for having a diagnosis of depression and anxiety is 1.4 (95% confidence interval (CI) =1.05-1.88), and the OR of redemption prescriptions of TCAs is 1.90 (CI=1.54-2.34) and OR is 1.34 (CI= 1.20-1.51) for SSRI. In the post-diagnostic period the OR is 1.23 (CI= 0.92-1.64) for depression and anxiety diagnosis. The OR is 6.70 (CI=5.81-7.72) for TCA and OR is 2.46 (CI= 2.25-2.69) for SSRI. Conclusion: During both the pre- diagnostic and post-diagnostic period, MS patient have increased risk of depression and anxiety diagnoses and redemption of antidepressant and anxiolytic prescriptions, compared to the background population.