Aims. To examine the direction of the longitudinal association between vulnerability for psychosis and cannabis use throughout adolescence. Design. Cross-lagged path analysis was used to identify the temporal order of vulnerability for psychosis and cannabis use, while controlling for gender, family psychopathology, alcohol use and tobacco use. Setting. A large prospective population study of Dutch adolescents [the TRacking Adolescents' Individual Lives Survey (TRAILS) study]. Participants. A total of 2120 adolescents with assessments at (mean) age 13.6, age 16.3 and age 19.1. Measurements. Vulnerability for psychosis at the three assessment points was represented by latent factors derived from scores on three scales of the Youth Self-Report and the Adult Self-Report, i.e. thought problems, social problems and attention problems. Participants self-reported on cannabis use during the past year at all three waves. Findings. Significant associations (r = 0.12-0.23) were observed between psychosis vulnerability and cannabis use at all assessments. Also, cannabis use at age 16 predicted psychosis vulnerability at age 19 (Z = 2.6, P < 0.05). Furthermore, psychosis vulnerability at ages 13 (Z = 2.0, P < 0.05) and 16 (Z = 3.0, P < 0.05) predicted cannabis use at, respectively, ages 16 and 19. Conclusions. Cannabis use predicts psychosis vulnerability in adolescents and vice versa, which suggests that there is a bidirectional causal association between the two.
© 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.
Aims. To investigate the influence of parenting styles (overprotection, emotional warmth, and rejection) in early adolescence on regular alcohol use in late adolescence. Methods. We analyzed data from the first three waves (mean ages: 11.09, 13.56, and 16.27 years, respectively) of a population-based prospective cohort study of 2,230 adolescents, conducted between 2001 and 2007. Adolescents reported on parental overprotection, emotional warmth, and rejection (T1). Regular alcohol use was defined as six and seven glasses or more a week for girls and boys, respectively. We further assessed family socioeconomic status, parental divorce, parental alcohol use, educational level of the adolescent, and alcohol use at baseline. Results. Parental overprotection had the strongest relationship to regular alcohol use: adolescents who perceived more parental overprotection were at increased risk of developing regular alcohol use, even after adjustment for several confounders. Rejection was not related to adolescents' alcohol use and, after adjustment for the other variables, neither was emotional warmth. Conclusion. Overprotective parenting is a determinant of future regular adolescent alcohol use and therefore health professionals should pay particular attention to those adolescents who have overprotective parents. The role of adolescent characteristics in the relationship between overprotection and alcohol use deserves further study.
Copyright © 2012 S. Karger AG, Basel.
Aims. To assess the influence of peer alcohol use during adolescence on young adults' alcohol use and abuse, and to assess to what extent parents' perception of their adolescent child's friends and adolescent's self-control modify this influence. Methods. We analyzed data from the first, third, and fourth wave of a population-based prospective cohort study of 2230 adolescents conducted between 2001 and 2010 (mean ages: 11.1, 16.3, and 19.1, respectively). Alcohol use and abuse were measured at T4 by self-report questionnaires and by the Composite International Diagnostics Interview (CIDI), respectively. Peer alcohol use, self-control, and parents' perception of their adolescent child's friends were measured at T3. We adjusted for gender, age, socioeconomic-status, parental alcohol use, and adolescent baseline alcohol use. Results. Peer alcohol use during adolescence was related to young adults' alcohol use and abuse [odds ratio (95% confidence interval): 1.31 (1.11-1.54) and 1.50 (1.20-1.87), respectively]. Neither parents' perception of their adolescent child's friends nor self-control modified this relationship. Alcohol abusers were more likely to have low self-control than alcohol users. No differences were found between alcohol users and abusers regarding their parents' perception of their friends and peer alcohol use. Conclusions. Peer alcohol use during adolescence affects young adults' alcohol use and abuse. We found that self-control was only related to alcohol abuse. Peer influence was not modified by parents' perception of peers or by self-control. Peer alcohol use and self-control should thus be separate targets in the prevention of alcohol use/abuse.