The transition into habitual smoking in high-risk adolescents

Despite serious well-known health risks, 31% of Dutch adolescents have tried
smoking, and 21% of 18 year olds smoke on a daily basis. While various
addiction models explain the continuation of substance dependence, the
transition from experimental to dependent substance use remains largely
unexplained. The current project aims to bridge this gap by developing a
neurocognitive model describing the mechanisms critically involved in the
transition from experimental to dependent smoking in low educated high-risk
adolescents.

The current project has two main objectives:
Research question 1 (RQ1): Is the transition from experimental to dependent
smoking in high-risk adolescents predicted by the strength of goal-directed and
impulse control systems as well as habit propensity? It is hypothesized that
experimental smokers with a stronger habit propensity and weaker goal-directed
and impulse control systems are more likely to develop nicotine dependence.
Research question 2 (RQ2): Is the transition from experimental to dependent
smoking associated with a shift from goal directed behaviour through positive
reinforcement (i.e., activation in the ventral striatum to smoking cues) to a
habitual response (i.e., activation in the dorsal striatum to smoking cues)? It
is hypothesized that transition into dependent smoking is associated with a
shift from ventral to dorsal striatal reactivity to smoking cues in a smoking
cue-reactivity paradigm.

A three-wave longitudinal study design will be employed. At baseline and at
1-year follow-up all the relevant brain systems will be measured using fMRI.
Additionally, smoking behaviour will be measured using ecological momentary
assessments (EMA) at baseline. An online questionnaire about smoking behavior
will completerd 6 months after the baseline measurements by the experimental
smokers. This longitudinal design allows us to use baseline fMRI measures to
predict the development of smoking behaviour over a 1-year time period. At
1-year follow-up, all relevant brain systems will be measured again to answer
RQ2. For this aim brain activation at baseline and 1-year follow-up will be
compared in those participants who develop nicotine dependence. A control group
of non-smokers will be included to investigate baseline differences in brain
activation between experimental smokers and non-smokers in order to contribute
to the development of a neurocognitive developmental model of addiction.

For the current study, participants will complete (online) questionnaires,
perform cognitive tasks on a computer and will undergo an MRI scanning session
two times. MRI measurements themselves do not pose any risk, with regards to
possible physical risks, if appropriate precautions are made. Furthermore
participation in the current study will only cause limited burden. No benefits
are related to participation in the current study. The inclusion of 12-18 years
old participants is necessary given that smoking is generally initiated during
this age period, especially in high-risk populations such as students following
low-education levels. Overall, we feel that the knowledge we gain through this
project, as well as the risk-free nature of this study, justifies the efforts
of the participants. The control group will only complete fMRI baseline
measures and cognitive tasks and questionnaires at baseline.