The scores reported in this work are true to diagnostic guidelines; hence, any internalizing symptoms that occurred in the context of alcohol and drug use, medication changes, co-occurring illness or birth are scored as absent. Depending on the intended use of the scores, this could be an asset or an additional limitation. Our approach makes most sense for scoring internalizing as a precursor to the initiation, exacerbation, or recurrence of substance problems, but might be problematic if scores are examined as mediators or moderators between life stressors or other forms of mental or physical illness and substance use. This potential limitation can be easily addressed by a minimal change in the code provided in the Supplementary Materials. These code changes permit the inclusion of symptoms occurring in the context of substance use, illness, or other circumstances. The psychometric properties of the Internalizing Scale based on these alterations are similar to the results reported above (results not shown).
