Association of Restless Legs Syndrome With Risk of Suicide and Self-harm

Source: Zhuang S, Na M, Winkelman JW, et al. Association of Restless Legs Syndrome With Risk of Suicide and Self-harm. JAMA Netw Open. Published online August 23, 20192(8):e199966. doi:10.1001/jamanetworkopen.2019.9966

Key Points

Questions  Is restless legs syndrome associated with a high risk of suicide and self-harm?

Findings  In a cohort study that included 169 373 participants, individuals with restless legs syndrome had a higher risk of suicide and self-harm compared with age- and sex-matched participants without restless legs syndrome, and the increased risk was independent of common diseases and conditions.

Meaning  Restless legs syndrome was associated with an increased risk of suicide and self-harm.

Abstract

Importance  Restless legs syndrome (RLS) is a common neurologic disorder that has been previously found to be associated with higher odds of suicidal ideation. In the context of the increasing suicide rate in the United States, the evidence regarding the association between RLS and the risk of suicide and self-harm is limited.

Objective  To investigate the association between RLS and risk of suicide and self-harm.

Design, Setting, and Participants  This cohort study was performed using Truven Health MarketScan national claims data from 2006 to 2014; the baseline data were from 2006 to 2008, and the follow-up data covered 6 years (January 1, 2009, to December 31, 2014). Included were 24 179 nonpregnant participants with RLS and 145 194 age- and sex-matched participants without RLS at baseline (2006-2008), who were free of suicide, self-harm, cardiovascular disease, or cancer at study baseline. Data analysis was performed from February 1, 2018, to January 1, 2019.

Exposure  Diagnosis of RLS, as identified by the International Classification of Diseases, Ninth Revision code.

Main Outcomes and Measures  Incident suicide and self-harm event, identified by the International Classification of Diseases, Ninth Revision diagnosis code.

Results  Among 169 373 participants in the current analysis, the mean (SD) age was 49.4 (9.1) years; 53 426 (31.5%) participants were men. During a mean (SD) follow-up duration of 5.2 (2.2) years, 119 incident suicide and self-harm cases were identified. Individuals with RLS had a higher risk of suicide or self-harm compared with those without RLS (adjusted hazard ratio, 2.66; 95% CI, 1.70-4.15), after adjusting for lifestyle factors (eg, alcohol and obesity), presence of chronic diseases (eg, depression, insomnia, diabetes, chronic kidney disease, peripheral neuropathy, iron-deficiency anemia, and Parkinson disease), and use of medications. Excluding those with depression, insomnia, obstructive sleep apnea, and other common chronic conditions, the significant association between RLS and suicide or self-harm persisted (adjusted hazard ratio, 4.14; 95% CI, 2.17-7.92).

Conclusions and Relevance  Restless legs syndrome was associated with a high risk of suicide and self-harm, and the risk was independent of most identified diseases and conditions.