BOSTON – Children who experiment with smoking even minimally before age 11 are more likely to take up smoking as teens than are their nonexposed peers, Jennifer Fidler reported at the annual meeting of the Society of Behavioral Medicine.
Because there is an apparent protracted period of dormant vulnerability–or “sleeper effect”–before social or environmental conditions trigger the onset of a stable smoking pattern, “interventions should target the prevention of first, short experimentation with smoking,” she said.
Using data from the 5-year longitudinal Health and Behavior in Teenagers Study (HABITS) of 5,000 British adolescents, which included yearly assessments of smoking status, Ms. Fidler and her colleagues at University College London calculated the probability of becoming a smoker as a function of having tried smoking just once by age 11.
Early one-time triers were significantly more likely than those who had never smoked at age 11–12 to take up current smoking for the first time up to 3 years later. The study data showed that very few participants reported current smoking at age 11–12, “making this an ideal time to study smoking progression,” she said.
After the investigators controlled for personal factors known to influence smoking–including ethnicity, socioeconomic deprivation, gender, family/peer smoking, and conduct problems–logistic regression analyses confirmed a statistically significant sleeper effect, Ms. Fidler said. The adjusted odds for taking up smoking at 1, 2, and 3 years following initial exposure relative to same-age nonexposed peers were 6.3, 2.9, and 2.1, respectively.
“Only after 4 years of nonsmoking following an initial try before age 11 was the difference between triers and nontriers not significant,” she said.
Various behavioral and biophysical conditions may contribute to the sleeper effect, including the possibility “that early nicotine exposure alters neurologic reward pathways,” Ms. Fidler said. “Or it may be that the first smoking experience breaks down such barriers to smoking as fear and insecurities about how to smoke, or that personality traits leading to the initial try may continue to stand individuals at an increased risk.”
From a policy perspective, the findings suggest that community interventions should be aimed at preventing early experimentation with smoking to reduce the risk of smoking uptake, Ms. Fidler said. Additionally, interventions should target adolescents who report having tried smoking, albeit just once, because of their increased risk of later smoking.