Neurological effects
Nicotine is widely recognized as a psychoactive substance126. Vapers experience craving, impaired capacity to stop and withdrawal symptoms during abstinence (e.g. irritability), which all suggest e-cigs potential of inducing nicotine dependence127,128. Similarly to other substance use disorders, adolescents are characteristically more vulnerable to addiction129.
Despite ENDS representing a tobacco cessation strategy, the risk of transition to conventional cigarettes in previously never smokers represents an emerging issue of critical relevance, especially in young people130–133. A recent meta-analysis showed that in a population of teens and young adults who have never smoked, odds of smoking initiation were 3 to 6 times higher in those who have ever used e-cigarettes134. Evidence suggest also that higher nicotine concentrations may heighten the likelihood of progression135. In this perspective, the renormalization of a smoking culture among teenagers threatens to subvert decades of anti-smoking efforts.
Structural and neurochemical changes in the central nervous system lie beneath the behavioral evolution that characterizes adolescence. Against this background, nicotine can affect its regular course, contributing to attention and cognitive deficits and exacerbating mood disorders136.
Furthermore, in such a critical phase of human development, nicotine exposure may prime the brain’s reward system increasing pleasing effects of other substances of abuse137,138. As evidence of this, youngsters smoking e-cigarettes display a greater risk of co-occurring alcohol and/or marijuana use139.