Previous cross-sectional research provided evidence for a relationship between environmental tobacco smoke (ETS) exposure and symptoms indicative of nicotine dependence in adolescent never- and experimental smokers. This study aims to examine temporal associations between nicotine dependence-like symptoms and ETS exposure, and whether this differs between never- and experimental smokers. Ecological momentary assessment data were collected in a sample of Dutch adolescent never-smokers (n=105; Mage=14.48; 30.5% male) and experimental smokers (n=72; Mage=16.57; 30.6% male). Participants self-rated dependence-related symptoms (pleasant, unpleasant, autonomy over smoking, dizziness, wanting, withdrawal-related symptoms) and ETS exposure three times a day for three weeks. Binomial generalized linear mixed effects models were applied examining 1) the association between ETS exposure and symptoms within the same interval, 2) whether ETS exposure precedes symptoms, and 3) vice versa. Analyses revealed a positive association between unpleasant symptoms and ETS exposure during ETS exposure for never-smokers. The experimental smokers experienced less autonomy over smoking within the same time interval, less wanting shortly after ETS exposure and fewer pleasant symptoms in the interval preceding ETS exposure. We did not find that ETS exposure precedes dependence-like symptoms. Temporal effects of ETS exposure differ between never- and experimental smokers. ETS exposure has a potentially aversive effect in never-smokers, while in experimental smokers may potentially contribute to developing nicotine dependence. Future research should increase the frequency of momentary assessments to investigate the processes in more detail.

As there is a significant gap in the development of preventive interventions tailored to adolescents, this study develops and preliminarily investigates the efficacy of a preventive intervention towards Problematic Smartphone Use (PSU) by referring to the metacognitive model. Six classes, a total of 93 high school students (75% females, Mage=16.26, SD = 1.24), were randomly assigned to either the Training or No Training group. The intervention spanned five weekly sessions, incorporating cognitive behavioral therapy and the conceptual change model to modify metacognitive beliefs. Pre- and post-test measures included daily time spent on the mobile phone, risky behaviors related to smartphone use, and metacognitive beliefs about smartphone use. A mixed ANOVA indicated a significant reduction in daily time spent on the mobile phone and risky behaviors related to smartphone use only in the Training group, with large effect sizes. Findings are promising and discussed in terms of future improvement.

Antisocial behavior is a known risk factor for substance use in adolescence, but the combined effects of antisocial and prosocial behaviors are unknown. This study examined whether five types of anti- and prosocial behaviors are associated with subsequent alcohol and substance use. A prospective longitudinal cohort study of 3817 adolescents (55.3% females) aged 15 at baseline (T1) and 17 at follow-up (T2). Self-reports at T1 measured antisocial behaviors (criminal behavior, conduct problems) and prosocial behaviors (global prosociality, general trust, institutional trust). T2 measures included alcohol use (hazardous use, alcohol use disorder), drug use, and nicotine use. Antisocial behaviors positively predicted all types of substance use (X2=5.79 to 59.07, p<0.001), while prosocial behaviors negatively predicted most substance use measures (X2=-5.64 to 86.14, p=0.862 to<0.001). After adjusting for covariance between antisociality and prosociality, it was found that conduct problems (X2=5.54 to 32.22, p=0.005 to<0.001), criminal behavior (X2=3.61 to 33.77, p=0.007 to<0.001), and institutional trust (X2=-3.92 to 27.56, p=0.262 to<0.001), were the most important predictors. Antisocial behaviors and deficits in institutional trust at age 15 are strong and unique predictors of substance use and alcohol use disorder by age 17. This specific spectrum of social behaviors during the critical phase of adolescence is of relevance from a prevention perspective to minimize the risk of later development of substance abuse.

Problematic social media use (PSMU) parallels traditional characteristics of substance use disorders, including salience, functional impairment, and tolerance. An excessive focus on social reward and engaging in negative behaviors on social media may decrease certain executive functions. However, the role of how inhibitory control processes manifest in PSMU are not well understood. The current study aims to explore both the presence of inhibitory control impairments and harmful online behaviors, such as negative social comparison, in problematic social media use. A population of emerging adults (undergraduate university students; N=503) completed several online questionnaires assessing problematic social media use, trait impulsivity, and negative social comparison on social media. An online Go-Nogo and Iowa Gambling Task were administered to further evaluate inhibitory control. Higher problematic social media use was significantly positively correlated with trait impulsivity, but not Go-Nogo or Iowa Gambling task performance. Negative social comparison on social media was a stronger predictor of PSMU, compared to inhibitory control measures. However, social comparison did not significantly interact with inhibitory control measures when predicting PSMU. When exploring subtypes of impulsivity, the strongest correlation with PSMU was observed with cognitive instability and attentional impulsivity. Our results suggest that aspects of impaired inhibitory control-namely, cognitive instability and attentional impulsivity-are present in problematic social media use. Understanding the interplay between features of addiction and the unique context of online socialization, such as negative social comparison, is central to defining problematic social media use as a potential behavioral addiction.