SCZ PRS were associated with elevated alcohol, cannabis, and cocaine involvement, along with nicotine use and non-problem opioid use (Supplementary Table S6). Relationships with non-problem cannabis use, severe cannabis dependence, and severe cocaine dependence survived multiple comparison correction. Associations with SCZ2 PRS were comparable and are described in the Supplementary Results (see also Supplementary Table S7; see Supplementary Figure S3 for a visual comparison to SCZ results). Alcohol: Elevated SCZ PRS were associated with severe alcohol dependence relative to all other categories of involvement (i.e., non-regular use, non-problem use, and use with fewer dependence symptoms). Cannabis: Elevated SCZ PRS were associated with cannabis use at all levels of involvement relative to non-use and differentiated those with severe dependence from non-problem users and users with mild problems. Cocaine: Higher SCZ PRS differentiated cocaine users with 1–2 and 6–7 dependence symptoms from non-users, and those with 6–7 symptoms from those with fewer (i.e., 0 and 3–5) symptoms. Nicotine: Elevated SCZ PRS were associated with nicotine use at all levels of involvement. Opioids: Higher SCZ PRS were associated with non-problem opioid use.
