To the Editor: In their article, published in the October 2008 issue of the Journal, Margaret Keyes, Ph.D., et al. (1) concluded that both genetic and environmental influences increase the risk of cigarette use in the adolescent children, biological and adoptive, of parents who smoke. The authors also found an association between parents who smoke and an increased likelihood for their biological offspring (more than adopted children) to engage in disinhibited behavior (generally defined by the authors as unacceptable social behavior). I applaud Dr. Keyes et al. for these thought-provoking findings.
However, I was surprised to see little to no emphasis on home environment/family dynamics and additional psychiatric diagnoses, which is information that could have been obtained via self-report, as seen with other methods of obtaining data in the study. Examples of the former that could have been explored as possible confounding variables are the presence of neglect or abuse in the adolescents’ homes or lack of parental supervision that may have contributed to disinhibited behavior (2). Examples of disinhibited behavior that could have been examined are the identification of bipolar or personality disorders. A sound effort to eliminate confounding variables was achieved by separating such disinhibited behavior from those seen in subjects with diagnoses of attention deficit hyperactivity disorder, conduct disorder, or oppositional defiant disorder and by identifying other types of substance use/misuse. It appears that a similar query of negative home influences and/or additional psychiatric diagnoses could have also been considered. Of note, socioeconomic background was taken into consideration, yet we cannot assume that a higher socioeconomic status is protective of adverse home conditions.
The author reports no competing interests.
This letter (doi: 10.1176/appi.ajp.2008.08111721) was accepted for publication in December 2008.