I suspect the effects are mental/emotional and a research team may not be conducting statistical research like group A/group B types of studies but there could

I suspect the effects are mental/emotional and a research team may not be conducting statistical research like group A/group B types of studies but there could be value in research on current 18-25 year olds, their social/mental/emotional well being and gathering info on how early they may have consumed it, frequency, along with rates of clinical disorders. Surveys or research on college campuses would probably be the easiest method of gathering data for that age group.