The Long-Term Relationship Between Cannabis and Heroin Use: An 18- to 20-year Follow-Up of the Australian Treatment Outcome Study (ATOS).

OBJECTIVE: Cannabis use is common among individuals with opioid use disorder, but it remains unclear whether cannabis use is associated with an increase or a reduction in illicit opioid use. To overcome limitations identified in previous longitudinal studies with limited follow-ups, the authors examined a within-person reciprocal relationship between cannabis and heroin use at several follow-ups over 18 to 20 years. METHODS: The Australian Treatment Outcome Study (ATOS) recruited 615 people with heroin dependence in 2001 and 2002 and reinterviewed them at 3, 12, 24, and 36 months as well as 11 and 18-20 years after baseline. Heroin and cannabis use were assessed at each time point using the Opiate Treatment Index. A random-intercept cross-lagged panel model analysis was conducted to identify within-person relationships between cannabis use and heroin use at subsequent follow-ups. RESULTS: After accounting for a range of demographic variables, other substance use, and mental and physical health measures, an increase in cannabis use 24 months after baseline was significantly associated with an increase in heroin use at 36 months (estimate=0.21, SE=0.10). Additionally, an increase in heroin use at 3 months and 24 months was significantly associated with a decrease in cannabis use at 12 months (estimate=-0.27, SE=0.09) and 36 months (estimate=-0.22, SE=0.08). All other cross-lagged associations were not significant. CONCLUSIONS: Although there was some evidence of a significant relationship between cannabis and heroin use at earlier follow-ups, this was sparse and inconsistent across time points. Overall, there was insufficient evidence to suggest a unidirectional or bidirectional relationship between the use of these substances.

Systematic review of the efficacy, effectiveness, and cost-effectiveness of stepped-care interventions for the prevention and treatment of problematic substance use.

BACKGROUND: Stepped-care is a commonly recommended and implemented care model across health care domains, including substance use. Despite their presumed efficient allocation of treatment resources, a current and robust evidence synthesis is needed on the efficacy, effectiveness and cost-effectiveness of stepped-care for substance use. METHODS: This systematic review analyzed articles describing evaluations of stepped-care models that measured the use of acutely psychoactive substances (i.e., alcohol, cannabis, hallucinogens, inhalants, opioids, sedatives, hypnotics, anxiolytics, and stimulants) as a primary or secondary outcome, in participants over 18 years old. The analysis investigated model and participant characteristics associated with treatment outcomes. RESULTS: The study team conducted a search of five databases of literature (PsychINFO, MEDLINE, Embase, Cochrane Library and Scopus) published between January 1, 2010, and November 1, 2020. The search yielded 1051 unique articles, 19 of which were included in the analysis. The studies had considerable variability in sample sizes (n = 18-2310), time to follow-up (4.5 months to 3 years), and retention rates (35.1-100 %). Studies examined outcomes for either alcohol alone (n = 9), alcohol and other drug use (n = 9), or drug use alone (n = 1). Most studies (n = 13;) were rated as good quality. Three (15.8 %) were rated as fair and three (15.8 %) were rated as poor quality. The evidence regarding the efficacy, effectiveness and cost-effectiveness of stepped-care approaches is limited, but four of seven studies found that adaptive-care interventions delivered in the context of other systemic interventions produced greater benefit than control conditions in relation to at least one alcohol-related outcome. We have insufficient evidence to determine whether the modes or intensity of interventions included in the models, or decision rules used to step people up or down to differing levels of care, have an impact on outcome. CONCLUSION: Heterogeneity between studies with regard to model and evaluation design limited the degree to which the analysis could draw robust conclusions. Sample recruitment and statistical power are particular challenges, and the field needs more innovative evaluation designs to assess the efficacy, effectiveness, and cost-effectiveness of stepped-care models.

A systematic review of the efficacy, effectiveness and cost-effectiveness of workplace-based interventions for the prevention and treatment of problematic substance use.

Employee alcohol and other drug use can negatively impact the workplace, resulting in absenteeism, reduced productivity, high turnover, and worksite safety issues. As the workplace can influence employee substance use through environmental and cultural factors, it also presents a key opportunity to deliver interventions, particularly to employees who may not otherwise seek help. This is a systematic review of workplace-based interventions for the prevention and treatment of problematic substance use. Five databases were searched for efficacy, effectiveness and/or cost-effectiveness studies and reviews published since 2010 that measured use of psychoactive substances (i.e., alcohol, cannabis, hallucinogens, inhalants, opioids, sedatives, hypnotics, anxiolytics, and stimulants) as a primary or secondary outcome, in employees aged over 18. Thirty-nine articles were identified, 28 describing primary research and 11 reviews, most of which focused solely on alcohol use. Heterogeneity between studies with respect to intervention and evaluation design limited the degree to which findings could be synthesized, however, there is some promising evidence for workplace-based universal health promotion interventions, targeted brief interventions, and universal substance use screening. The few studies that examined implementation in the workplace revealed specific barriers including lack of engagement with e-health interventions, heavy use and reluctance to seek help amongst male employees, and confidentiality concerns. Tailoring interventions to each workplace, and ease of implementation and employee engagement emerged as facilitators. Further high-quality research is needed to examine the effectiveness of workplace substance use testing, Employee Assistance Programs, and strategies targeting the use of substances other than alcohol in the workplace. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=227598, PROSPERO [CRD42021227598].