Factors described above were included in the model. Time varying measures were produced for conduct disorder, monthly alcohol use, alcohol dependence, weekly tobacco use, tobacco dependence, other drug use, other drug dependence, childhood sexual abuse, and depressive episode. These variables were coded as present for each year after the age of onset, and were only included in the model if they were positive prior to the onset of cannabis use opportunity for model one, or prior to the onset of dependence for model two (e.g., if age at opportunity to use cannabis was 13, then conduct disorder with an age of onset of 14 was coded as absent prior to the onset of opportunity).
