in the analysis along with several additional auxiliary variables. These included variables found to be predictive of missingness (see supplementary tables 1a and b), indicators of socioeconomic adversity, personal characteristics, and maternal psychopathology as well as strong correlates of the outcome variables, such as similar measures from the domains of mental health and substance use collected earlier in the study. Although we cannot say with absolute certainty that the data were missing at random, we feel justified in making the missing at random assumption in this instance, given the wealth of auxiliary information available. Monte Carlo errors are available on request.
