BZD Misuse History and Recency in Opioid Use Disorder

This study assesses patients currently in treatment (baseline visit) for their opioid and potentially other substance use disorder(s) who are not presently clinically stable, which we defined a priori as early (first 6 months) in treatment or in treatment longer but self-report having used opioids during the past month. As this programmatic research is thematically focused on BZD/opioid polysubstance use, we attempted to recruit a sample enriched with individuals with a history of BZD misuse in addition to their opioid misuse; however, we did not explicitly require a history of, or current, use of BZDs to be enrolled in this study.
First, we defined BZD misuse history based on two lifetime factors, either: (1) any BZD misuse based on a “yes” response to the question, “Have you ever used sedatives/hypnotics not as prescribed intending to get high,” on the Drug History and Use Questionnaire DHUQ (described in Section “2.3.4. Substance use”), or (2) diagnosis of sedative use disorder involving a BZD based on the SCID diagnostic interview (described in Section “2.3.5. Psychopathology and affective dysregulation”). Any participant meeting at least one of these two criteria was classified as a lifetime BZD misuser, and any participant not meeting either criterion was classified as a BZD never-misuser. Importantly, any participant who reported using BZDs as exactly prescribed for them throughout their lifetime, and denied misuse, was classified as a never-misuser. Second, to account for possible temporal variation in the effects of BZD misuse or abstinence, we defined differences in recency of BZD misuse as either (1) more than 1 year ago, or (2) within the past year, relative to the date of the initial screening visit. Participants who reported BZD misuse more than 1 year prior, or met DSM-5 criteria for partially remitted or past sedative use disorder were classified as misusers more than a year ago. Participants who reported BZD misuse within the past year, or met DSM-5 criteria for current (past-year) sedative use disorder involving a BZD, were classified as past-year misusers. Thus, we formed three distinct groups for analyses: (1) never misuse, (2) misuse > 1 year ago, and (3) past-year misuse of BZDs.
All participants are adults, ages 18–70 years old enrolled in a substance use disorder treatment program (outpatient or residential) in the Detroit metropolitan region. Exclusion criteria were estimated IQ < 80, expired breath alcohol > 0.02% breath alcohol concentration, neurological disorders that affect cognition, and current psychosis or suicidality. This study is also approved to re-contact participants (in-person or remotely) for 3-month follow-up assessment; these follow-up data will be reported elsewhere.