title: Prenatal Maternal Smoking and Increased Risk for Tourette Syndrome and Chronic Tic Disorders.
abstract: 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).
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
authors: Division of Tics, Obsessive-Compulsive Disorder (OCD) and Related Disorders, Icahn School of Medicine at Mount Sinai, New York.
authors: Heidi A
authors: HA
authors: Browne
authors: Seaver Autism Center, Icahn School of Medicine at Mount Sinai.
authors: Amirhossein
authors: A
authors: Modabbernia
authors: Seaver Autism Center, Icahn School of Medicine at Mount Sinai; Friedman Brain Institute and Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai.
authors: Joseph D
authors: JD
authors: Buxbaum
authors: Section for Biostatistics.
authors: Stefan N
authors: SN
authors: Hansen
authors: Section for Epidemiology, Aarhus University, Denmark; National Centre for Register-Based Research, Aarhus University.
authors: Diana E
authors: DE
authors: Schendel
authors: Section for Biostatistics.
authors: Erik T
authors: ET
authors: Parner
authors: Seaver Autism Center, Icahn School of Medicine at Mount Sinai; Friedman Brain Institute and Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai.
authors: Abraham
authors: A
authors: Reichenberg
authors: Division of Tics, Obsessive-Compulsive Disorder (OCD) and Related Disorders, Icahn School of Medicine at Mount Sinai, New York; Friedman Brain Institute and Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai. Electronic address: dorothy.grice@mssm.edu.
authors: Dorothy E
authors: DE
authors: Grice
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000453:epidemiology / Q000209:etiology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced* / Q000453:epidemiology; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D013981:Tic Disorders / Q000453:epidemiology / Q000209:etiology*; D005879:Tourette Syndrome / Q000453:epidemiology / Q000209:etiology
keywords: Tourette syndrome; chronic tic disorder; obsessive-compulsive disorder; prenatal; smoking