Does exposure to maternal smoking during pregnancy affect the clinical features of ADHD? Results from a controlled study

Abstract

Objectives. Exposure to maternal smoking during pregnancy may be a significant risk factor for attention-deficit/hyperactivity disorder (ADHD) independently of family history of ADHD. The main aim of this study was to examine whether the clinical profile of ADHD differs between children with and without exposure to maternal smoking during pregnancy. Methods. This was a case–control study of boys and girls with and without ADHD ascertained from psychiatric and paediatric sources. Maternal smoking during pregnancy was defined by interviews with subjects’ mothers. Main outcome measures were ADHD symptoms and associated clinical features in children with and without exposure to maternal smoking during pregnancy. Results. No significant differences were found between ADHD children with and without exposure to maternal smoking during pregnancy on clinical characteristics. When these analyses were repeated in the subgroup of subjects without parental history of ADHD, there were also no statistically significant differences found. Conclusions. Despite adequate statistical power, no significant differences were found between ADHD children with and without exposure in the clinical features of ADHD and associated disorders. Results provide support for the notion that ADHD cases resulting from exposure to maternal smoking during pregnancy have similar clinical profiles as other ADHD cases.

Key Words::

• ADHD
• smoking
• children
• brain development
• childhood ADHD

Acknowledgements

This work was supported by the Pediatric Psychophar macology Philanthropy Fund. The funding organization did not play any role in the design and conduct of the study, the collection, management analysis and interpretation of the data, or in the preparation, review or approval of the manuscript.

Statement of Interests

Dr Joseph Biederman is currently receiving research support from the following sources: Elminda, Janssen, McNeil, and Shire. In 2010, Dr Biederman did not receive any outside income. In 2009, Dr Biederman received a speaker's fee from the following sources: Fundacion Areces, Medice Pharmaceuticals, and the Spanish Child Psychiatry Association. In previous years, Dr Biederman received research support, consultation fees, or speaker's fees for/ from the following additional sources: Abbott, Alza, AstraZeneca, Bristol Myers Squibb, Celltech, Cephalon, Eli Lilly and Co., Esai, Forest, Glaxo, Gliatech, Janssen, McNeil, Merck, NARSAD, NIDA, New River, NICHD, NIMH, Novartis, Noven, Neurosearch, Organon, Otsuka, Pfizer, Pharmacia, The Prechter Foundation, Shire, The Stanley Foundation, UCB Pharma, Inc. and Wyeth. In the past year, Dr Stephen Faraone has received consulting fees and has been on Advisory Boards for Eli Lilly, Ortho-McNeil and Shire Development and has received research support from Eli Lilly, Pfizer, Shire and the National Institutes of Health. In previous years, Dr Faraone has received consulting fees or has been on Advisory Boards or has been a speaker for the following sources: Shire, McNeil, Janssen, Novartis, Pfizer and Eli Lilly. In previous years he has received research support from Eli Lilly, Shire, Pfizer and the National Institutes of Health. Dr Bhide, Mr Petty and Ms Woodworth have nothing to disclose.