Prenatal Maternal Smoking and Increased Risk for Tourette Syndrome and Chronic Tic Disorders

J Am Acad Child Adolesc Psychiatry. 2016 Sep;55(9):784-91. doi: 10.1016/j.jaac.2016.06.010. Epub 2016 Jul 21.

Abstract

Objective: We assessed the role of prenatal maternal smoking in risk for Tourette syndrome and chronic tic disorder (TS/CT) and pediatric-onset obsessive-compulsive disorder (OCD).

Method: In an analysis of 73,073 singleton pregnancies from the Danish National Birth Cohort, we calculated incidence rates (IR) per 1,000 person-year for TS/CT and OCD. We then determined crude and adjusted hazard ratios and 95% CIs associated with prenatal maternal smoking, considering smoking as a dichotomous (yes/no) variable or a stratified variable (no smoking, light smoking, and heavy smoking [≥10 cigarettes/day]). Additional analyses examined the effect of maternal smoking on risk for TS/CT with other comorbid psychiatric conditions.

Results: In final adjusted analyses, heavy smoking was associated with a 66% increased risk for TS/CT (adjusted hazard ratio = 1.66, 95% CI = 1.17-2.35). In addition, heavy smoking was associated with a 2-fold increased risk for TS/CT with comorbid attention-deficit/hyperactivity disorder (ADHD), and both light and heavy smoking were associated with a more than 2-fold increased risk for TS/CT with any non-ADHD psychiatric comorbidity. Our parallel analyses of pediatric-onset OCD were likely underpowered but showed similar relationships.

Conclusion: Prenatal maternal smoking was associated with increased risk for TS/CT as well as TS/CT with comorbid psychiatric conditions, even after adjustment for several important variables, including maternal psychiatric history, socioeconomic status, and partner smoking. Our findings point to a pathway linking prenatal tobacco exposure and altered brain development to TS/CT.

Keywords: Tourette syndrome; chronic tic disorder; obsessive-compulsive disorder; prenatal; smoking.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Cohort Studies
  • Denmark / epidemiology
  • Female
  • Humans
  • Infant
  • Male
  • Obsessive-Compulsive Disorder / epidemiology
  • Obsessive-Compulsive Disorder / etiology*
  • Pregnancy
  • Prenatal Exposure Delayed Effects / chemically induced*
  • Prenatal Exposure Delayed Effects / epidemiology
  • Smoking / adverse effects*
  • Smoking / epidemiology
  • Tic Disorders / epidemiology
  • Tic Disorders / etiology*
  • Tourette Syndrome / epidemiology
  • Tourette Syndrome / etiology