Risk of Suicidal Ideation and Behavior Following Early-Onset Idiopathic Restless Legs Syndrome Treatment.

Purpose: To estimate incidence rates of suicidal ideation and behavior following treatment initiation with gabapentinoids or dopamine agonists (DAs) in patients with newly diagnosed early-onset idiopathic restless legs syndrome (RLS) and to examine suicidal behavior risk, comparing between those receiving gabapentinoids and DAs.

Methods: A new user retrospective cohort study using MarketScan claims data from 2012 to 2019 was conducted. Exposures were monotherapy gabapentinoids or DAs initiated within 60 days of new RLS diagnosis. Three varying outcome measures of suicidality were examined and incidence rates were calculated for each. A log-binomial regression model the estimated relative risk (RR) of the outcomes with gabapentinoids. Propensity score weighting adjusted for baseline covariates, including age, substance use disorders, hyperlipidemia, antipsychotic use, hypnotic/sedative use, and mood stabilizer use, which were most imbalanced before weighting.

Results: The cohort included 6672 patients, with 4986 (74.7%) initiating a DA and 1686 (25.3%) initiating a gabapentinoid. Incidence rates for all outcome measures were higher in the gabapentinoid group (suicidality: 21.6 vs. 10.7 per 1000 person-years; suicidality with self-harm: 23.0 vs. 11.1 per 1000 person-years; overdose- and suicide-related events: 30.0 vs. 15.5 person-years). Associated risk of suicidality (adjusted RR, 1.27 [95% CI, 0.86-1.88]); suicidality with self-harm (adjusted RR, 1.30 [95% CI, 0.89-1.90]); or overdose- and suicide-related events (adjusted RR, 1.30 [95% CI, 0.93-1.80]) was not significant with gabapentinoids.

Conclusions: Incidence rates for suicidal ideation and behavior were higher among the gabapentinoid group, although increased risk was not detected after adjustment. A possible signal cannot be ruled out given limitations of the data and rarity of the outcome.