**Script explanation**
All scripts for analysis in MPLUS are provided here (a copy is also on GitHub, http://github.com/joellepasman/TRAILS_substanceuse/).
The script names for the exploratory factor analysis (EFA) follow the format efa_construct* (with construct being the latent variable that is modeled (either a predictor or outcome construct) and * representing the modeling step. The script names for the structural equation models (SEM) follow the format outcome_parentingfactor_model step.
Outcomes included a latent factor for smoking (fsmk), alcohol per week (alc), and cannabis initiation (can). Parenting factors included F1 parental involvement (f1inv), F2 parental substance use (f2sub), and F3 the parent-child relationship (f3rel). The modeling steps were ‘1main’ for the main effects of the PGS and the parenting factor, ‘2interactioneffects’ for the GxE between the PGS and the parenting factor, ‘3rgeeffects’ for the rGE effects, and ‘4full’ for the complete model including main, GxE, and rGE effects.
Further explanations for each of the scripts is included in the 'scripts info' document.
The following abbreviations are used in the scripts to represent the variables:
C1-C10 Principal components for genetic ancestry
parknow Parental knowledge
pardisc Child disclosure
parcont Parental control
parsol Parental solicitation
rel_rej Parent-child relationship rejection
rel_warm Parent-child relationship warmth
parsmk Parental smoking
parcpd Parental cigarettes per day
paralc Parental alcohol use per week
paraddep Parental addiction
parcan Parental cannabis use
prssmcpd Smoking PGS (based on smoking initiation and cigarettes per day)
prsalc Alcohol use PGS
prscan Cannabis initiation PGS
eversmk Ever smoking
dailysmk Daily smoking
cpd Cigarettes per day
ftnd Nicotine dependence
alc Alcohol use per week
alcmonth Any alcohol use in past month (yes/ no)
audit Alcohol Use Disorder Identification Test total score
can Cannabis initiation
cupit1 Cannabis Use Disorder Identification Test subscale 1 (impaired control) score
cupit2 Cannabis Use Disorder Identification Test subscale 2 (cannabis problems) score
