Associations between polysubstance use and psychiatric problems in a criminal justice population in Sweden.

BACKGROUND: Polysubstance use is common in substance users, and may complicate their clinical course. This study, in a criminal justice setting in Sweden, examines the association between the number of concurrently used substance types and psychiatric symptoms during 30 days before incarceration, while controlling for background variables such as family history (drug and alcohol problems, psychiatric problems, criminality), demographic data and history of emotional, physical or sexual abuse. METHODS: The data material comprised 5659 criminal justice clients reporting a substance use problem, examined with the Addiction Severity Index. Variables were compared in a multinomial regression analysis, comparing clients reporting one (n=1877), two (n=1408), three (n=956), four (n=443) and five or more (n=167) substance types. RESULTS: The 30-day prevalence of most psychiatric symptoms included in the study (depression, anxiety, cognitive problems, hallucinations, difficulty controlling violent behaviour, suicidal ideation, suicide attempts) was higher in individuals with a higher number of concurrent substance types used. In multinomial regression analysis, while controlling for background variables, these associations remained for concurrent suicidal ideation, cognitive problems, hallucinations and violent behaviour, with the latter two being associated with the higher numbers of substance types. Binge alcohol drinking, tranquilizers, opioids and the number of substance types reported were associated with several of the psychiatric symptoms. CONCLUSIONS: In the present criminal justice setting in Sweden, the use of multiple substance types and concurrent psychiatric symptoms appear to be associated, and a sub-group reporting particularly high numbers of concurrent substance types are particularly likely to report potentially severe psychiatric problems