difficult (see Knopik et al., 2009 for a review). This is indeed supported by recent work from our own group and others suggesting that maternal smoking during pregnancy is correlated with many risk factors, such as lower levels of maternal education (D’Onofrio, Singh, Iliadou, Lambe, Hultman, Neiderhiser, et al., 2010), spousal/significant other substance dependence (Knopik et al., 2006; Knopik, et al., 2005), nicotine dependence (Agrawal, et al., 2008), as well as maternal ADHD and other psychopathology (D’Onofrio, Singh, Iliadou, Lambe, Hultman, Neiderhiser, et al., 2010; Huizink & Mulder, 2006; Knopik, 2009; Knopik, Jacob, Haber, Swenson, & Howell, 2009), which may come with a host of additional influences on intrauterine environment that also predict poor offspring performance.
