ALSPAC and Adolescent Substance Use Trajectories: Consolidation of a UK research resource

Substance misuse and dependence among adolescents and young people in the UK is among the highest in Europe. Substance use, though typically initiated in adolescence, is heterogeneous and likely to follow different patterns or trajectories among different people. This matters because specific trajectories of substance use may have a different range of causes and maybe more likely to lead to poor adolescent and adult outcomes. These characteristics and patterns maybe missed if adolescent substance use is treated as a single average measure. Research, therefore, into this area needs to identify the common types of substance use trajectory in order then to test and explore specific research questions concerning their cause, or who may benefit or needs to be targeted by prevention activities. This also will require detailed information on early life, before substance use, as well as information on how substance use develops during adolescence. The Avon Longitudinal Study of Parents and Children (ALSPAC) of 13,000 children is the largest birth cohort with such information in the world, with participants? self-reported substance use (tobacco, alcohol, cannabis and other illicit drugs) assessed regularly since the age of ten. In addition, biological measures of substance use through hair and urine screens were collected at age 15 and 17, and information from a genomewide scan is available on 3000 subjects. We aim to bring the data collected on substance use and potential risk factors together in order to create an accessible research resource. We aim to identify and make available the different trajectories of adolescent substance use; compare and validate self-reported data with toxicological evidence; create an accessible database of self-reported substance use and identify all the key measures that have been collected in ALSPAC that may be involved in increasing or decreasing the risk of substance use; and conduct preliminary comparisons of whole genome scans of people with and without different substance use trajectories to identify potential genetic sites for further investigation.

Substance misuse and dependence among adolescents and young people in the UK is among the highest in Europe. Substance use, though typically initiated in adolescence, is likely to follow different patterns or trajectories with implications for research. Specific trajectories of substance use may have different aetiological pathways and maybe more likely to lead to poor adolescent and adult outcomes, which maybe missed if average ?values? of substance use are used. Research, therefore, into this area needs to identify the common types of substance use trajectory in order then to test and explore specific hypotheses on aetiology, or on who may benefit or needs to be targeted by prevention activities. The Avon Longitudinal Study of Parents and Children (ALSPAC) is the largest birth cohort with detailed biological and behavioural data from before birth through till late adolescence in the world. ALSPAC is organised as a resource for the whole scientific community. Approximately 13,000 children along with their parents were recruited to ALSPAC between 1991 and 1992. Participants? self-reported substance use (tobacco, alcohol, cannabis and other illicit drugs) has been assessed regularly since the age of ten, and at age 15 and 17 these self-reports have been augmented by hair-based toxicology. In addition, genomewide SNP data is available on 3000 subjects. We aim to consolidate the data collected on substance use and related covariates in order to create an accessible research resource. In particular, we aim to:-

1) identify different trajectories of adolescent substance use - both drug specific (ie. alcohol, tobacco, and cannabis) and overall;

2) compare and validate self-reported data with toxicological evidence based on hair analysis (cannabis, amphetamines, ecstasy, methamphetamine, opiates, cocaine, benzodiazepines, and ketamine) and urinalysis (cotinine).

3) create an accessible database of self-reported substance use amongst ALSPAC participants from ages ten to 17 years

4) conduct preliminary case control of substance use trajectories among 3000 study members with whole genome data in order to identify genetic loci of possible influence

5) identify, collate, and make available information on key predictors, mediating factors, and confounders of substance use collected in ALSPAC (such as:- social position, family adversity, parental and prenatal substance use, impulsivity, conduct problems, subjective response, peer substance use, depression, life events, sexual maturation, and neighbourhood).

6) provide univariate analyses of these factors on substance use trajectories in order to support researchers and research clusters test specific hypotheses on causal pathways determining adolescent substance use.