To Örebro University

BACKGROUND: Tourette syndrome (TS) and chronic tic disorder (CTD) may be associated with an increased risk of mortality, but specific causes of death are poorly understood. OBJECTIVES: In this matched cohort and sibling cohort study, we estimated the risk of all-cause and cause-specific mortality in individuals with TS/CTD, compared with unaffected matched individuals and unaffected full siblings.

METHODS: We identified all individuals diagnosed with TS/CTD in the Swedish National Patient Register who were living in the country between 1973 and 2020 and matched them (1:10) to individuals without TS/CTD from the general population. We also identified their siblings without TS/CTD. All-cause and cause-specific mortality outcomes, based on the International Classification of Diseases codes, were extracted from the Cause of Death Register. Covariates included sociodemographic variables and psychiatric disorders. Risks of mortality were estimated using Cox proportional hazards regression models.

RESULTS: We included 10,280 individuals with TS/CTD and 102,800 matched individuals without TS/CTD. In adjusted models, individuals with TS/CTD had an 86% increased hazard of all-cause mortality (hazard ratio: 1.86, 95% confidence interval: 1.65-2.11). The increased risk was observed for both natural (particularly nervous, digestive, and respiratory system diseases) and unnatural causes of death (including suicides and accidents). The sibling comparison showed similar results, indicating that the associations were unlikely to be explained by familial confounding.

CONCLUSIONS: Individuals with TS/CTD are at increased risk of death due to both natural and unnatural causes. As some of these deaths are potentially preventable, greater focus on the somatic health of individuals with TS/CTD is warranted.