The present study evaluated the developmental moderation of cigarettes smoked per day by a SNP score derived from a meta-analysis of current smokers. The results suggest developmental moderation with an increased effect at age 20 and 24, and decreased effect at age 14 and 17. These results are consistent with the notion that nicotine-specific substance use risk is less important at younger ages, and becomes more important as individuals age into adulthood. The SNP score was unrelated to alcohol use at any age, indicating that the SNP score effects are specific to nicotine, and do not tap more general etiological processes simultaneously relevant to nicotine and alcohol use.
