Objective: There is growing evidence that anhedonia is a commonly experienced symptom among substance-using populations. This systematic review synthesises findings across a range of substances to address questions regarding the time course of anhedonia, how anhedonia relates to other symptoms of substance dependence and whether it is similarly prevalent across all addictive drugs. Method: A literature search was conducted on PubMed, PsycINFO and MEDLINE, yielding 32 studies that used self-report measures of anhedonia among participants with a history of a substance abuse, dependence or long-term daily use of addictive substances. Results: Findings from these studies indicate that anhedonia (1) is elevated in samples dependent on a range of substances; (2) typically appears as a consequence of substance abuse or dependence, and diminishes with abstinence; and (3) predicts increased drug cravings and the likelihood of relapse in those attempting abstinence. Conclusions: The common experience of anhedonia in substance-dependent populations, and its relationship to relapse, emphasises the importance of developing therapeutic interventions that specifically target anhedonia in the treatment of all substance use disorders.

Background and Aims: Our understanding of patient pathways through specialist Alcohol and Other Drug treatment and broader health/welfare systems in Australia remains limited. This study examines how treatment outcomes are influenced by continuity in specialist Alcohol and Other Drug treatment, engagement with community services and mutual aid, and explores differences between clients who present with a primary alcohol problem relative to those presenting with a primary drug issue. Method: In a prospective, multi-site treatment outcome study, 796 clients from 21 Alcohol and Other Drug services in Victoria and Western Australia completed a baseline interview between January 2012 and January 2013. A total of 555 (70%) completed a follow-up assessment of subsequent service use and Alcohol and Other Drug use outcomes 12-months later. Results: Just over half of the participants (52.0%) showed reliable reductions in use of, or abstinence from, their primary drug of concern. This was highest among clients with meth/amphetamine (66%) as their primary drug of concern and lowest among clients with alcohol as their primary drug of concern (47%), with 31% achieving abstinence from all drugs of concern. Continuity of specialist Alcohol and Other Drug care was associated with higher rates of abstinence than fragmented Alcohol and Other Drug care. Different predictors of treatment success emerged for clients with a primary drug problem as compared to those with a primary alcohol problem; mutual aid attendance (odds ratio = 2.5) and community service engagement (odds ratio = 2.0) for clients with alcohol as the primary drug of concern, and completion of the index treatment (odds ratio = 2.8) and continuity in Alcohol and Other Drug care (odds ratio = 1.8) when drugs were the primary drugs of concern. Conclusion: This is the first multi-site Australian study to include treatment outcomes for alcohol and cannabis users, who represent 70% of treatment seekers in Alcohol and Other Drug services. Results suggest a substantial proportion of clients respond positively to treatment, but that clients with alcohol as their primary drug problem may require different treatment pathways, compared to those with illicit drug issues, to maximise outcomes.

People seeking treatment for substance use disorders often have additional health and social issues. Although individuals presenting with alcohol as the primary drug of concern (PDOC) account for nearly half of all treatment episodes to the Australian alcohol and other drug (AOD) service system, previous treatment cohort studies have focused only on the profile of Australian heroin or methamphetamine users. While studies overseas indicate that clients seeking treatment primarily for their drinking are less likely to experience social and economic marginalisation than those seeking treatment primarily for illicit or pharmaceutical drug use, very little research has directly compared individuals presenting with alcohol as the PDOC to those primarily presenting with other drugs as their PDOC. Seven hundred and ninety-six participants were recruited at entry to specialist AOD treatment in Victoria and Western Australia, and completed measures of demographic and social factors, substance use, quality of life, service use, and criminal justice involvement. We compared those with alcohol as their PDOC to those with other drugs as their PDOC using Pearson chi-square and Mann–Whitney U tests. Rates of social disadvantage, poor quality of life, high severity of substance dependence, and past-year AOD, mental health, acute health, and social service use were high in all groups. However, participants with alcohol as the PDOC were older; more likely to have an educational qualification; less likely to report criminal justice involvement, housing/homelessness service use, tobacco smoking, or problems with multiple substances; and reported better environmental quality of life; but were more likely to have used ambulance services, than those with other drugs as their PDOC. While those seeking treatment primarily for alcohol problems appear less likely to suffer some forms of social and economic disadvantage or to use multiple substances than those with a primary drug problem, they experience similarly high levels of substance dependence severity and mental health and AOD service use. These findings reinforce the need for AOD services to integrate or coordinate care with programs that address the many complexities clients frequently present with, while also acknowledging differences between those seeking treatment for alcohol versus other drug problems.