Cigarette Smoking During Pregnancy Associated With Schizophrenia in Offspring

Although many genetic and environmental factors influence the complex, bidirectional relationship between tobacco use and mental illness, it is well established that nicotine dependence is highly prevalent in individuals diagnosed with serious neuropsychiatric disorders.¹ The association of tobacco use during pregnancy with psychiatric disorders such as schizophrenia in the offspring, however, is less understood.

For the first time to date, new research findings published today in The American Journal of Psychiatry indicate that nicotine exposure to cigarette smoking during pregnancy is associated with schizophrenia in offspring.²

According to the Centers for Disease Control and Prevention (CDC) report, an estimated 19% of adults in the United States smoked cigarettes in 2011.³ Prenatal nicotine exposure, even with maternal smokeless tobacco use, has been related to numerous postnatal adverse health outcomes in newborns including low birth weight, preterm delivery, and sudden infant death syndrome.⁴ Due to its many adverse effects on fetal brain development,⁵ maternal tobacco smoking during pregnancy is also associated with long-term neurodevelopmental abnormalities and child behavioral problems such as attention-deficit/hyperactivity disorder (ADHD), conduct disorder and antisocial behavior, and depression and anxiety.⁶ In addition, rodent studies indicate that prenatal nicotine exposure may be associated with impaired fertility, type 2 diabetes, obesity, hypertension, and respiratory dysfunction.⁷

In the present study, a team of investigators affiliated with the Columbia University’s Mailman School of Public Health in New York city identified nearly 1000 cases of schizophrenia in offspring of mothers who used tobacco while pregnant. The comparison participants were then matched to these cases on date of birth, sex, and residence. The authors also measured the level of maternal serum cotinine, a metabolite of nicotine, to distinguish cigarette smokers from nonsmokers. Although they were unable to control for maternal alcohol intake, the use of a large nationwide sample, as well as the use of cotinine as a biomarker, adds strength and credibility to this study. After adjusting for potential confounding factors including parental psychiatric history, socioeconomic status, maternal age and C-reactive protein level, offspring exposed to in utero nicotine exhibited more than a 3 fold increased risk for schizophrenia (OR=3.41, 95% CI 1.86-6.24). It’s worth noting that the same group of investigators reported previously that prenatal nicotine exposure is also associated with bipolar disorder in offspring.⁸

Given the relatively high prevalence (20% to 25%) of tobacco use among pregnant women, smoking cessation strategies in pregnancy should be widely implemented. Importantly, findings indicate that behavioral counseling interventions show the greatest promise for abstinence from cigarette smoking in both the general population and among pregnant women.⁹

References

1. Pal A, Balhara YPS. A review of impact of tobacco use on patients with co-occuring psychiatric disorders. Tob Use Insights. 2016;9:7-12.

2. Niemela S, Sourander A, Helja-Marja S, et al. Prenatal nicotine exposure and risk of schizophrenia among offspring in a national birth cohort. Am J Psychiatry. 2016. 10.1176/appi.ajp.2016.15060800. [Epub ahead of print]

3. Centers for Disease Control and Prevention (CDC). Current cigarette smoking among adults – United States, 2011. MMWR Morb Mortal Wkly Rep. 2012;61:889-894.

4. Inamdar AS, Croucher RE, Chokhandre MK, et al. Maternal smokeless tobacco use in pregnancy and adverse health outcomes in newborns: a systematic review. Nicotine Tob Res. 2015;17:1058-1066.

5. Ekblad M. Smoking during pregnancy affects foetal brain development. Acta Paediatr. 2015;104:12-18.

6. Tiesler CMT, Heinrich J. Prenatal nicotine exposure and child behavioural problems. Eur Child Adolesc Psychiatry. 2014;23:913-929.

7. Bruin JE, Gerstein HC, Holloway AC. Long-term consequences of fetal and neonatal nicotine exposure: a critical review. Toxicol Sci. 2010;116:364-374.

8. Talati A, Bao Y, Kaufman J, et al. Maternal smoking during pregnancy and bipolar disorder in offspring. Am J Psychiatry. 2013;170:1178-1185.

9. Patnode CD, Henderson JT, Thompson JH, et al. Behavioral counseling and pharmacotherapy interventions for tobacco cessation in adults, including preganant women: a review of reviews for the U.S. Preventative Services Task Force [Internet]. Agency for Healthcare Research and Quality (US); 2015 Sep. Report No. 14-05200-EF-1.