Supplementary Material for: The Use of Antidepressant Medication before and after the Diagnosis of Amyotrophic Lateral Sclerosis: A Population-Based Cohort Study

Background: The prevalent use of antidepressants (ATDs) in patients with Amyotrophic Lateral Sclerosis (ALS) varies across cross-sectional and clinic-based published studies. This population-based cohort study assesses the real-world prevalence of the use of ATDs, its trajectory and the association of incident use with clinical characteristics. Methods: All patients with incident ALS in the Friuli Venezia Giulia region, Italy, from 2002 to 2009, were identified through multiple sources including health databases. Diagnosis was validated through clinical documentation review. ATDs prescriptions from 2000 to 2011 were obtained from regional database. The trajectory was estimated through generalized estimating equations for repeated measures logistic regression and the Hazard ratio (HR) of initiating ATDs through multivariate proportional hazard Cox regression. Results: In this cohort of 261 ALS cases, age-, sex-adjusted prevalence of the use of ATDs was 37.3%, higher than in general population. The trajectory increased by 16% in 1-year period across diagnosis. Age ≤67 years at diagnosis (HR 1.28, 95% CI 0.84-1.95) and bulbar onset (1.43, 95% CI 0.90-2.26) were positively associated with initiating ATDs after diagnosis. Conclusions: More than one-third of patients used ATDs. Depression may occur more frequently than previously reported. Depression may precede motor alterations and be related to both ALS diagnosis and progression.