Heroin Treatment Reduced Use of Most Drugs Over 18 Months, but Cannabis and Alcohol Use Stayed the Same

What the researchers found

Researchers followed 100 heroin-dependent people in London over 18 months of NHS treatment. Heroin use days in the prior month dropped significantly, as did cocaine, benzodiazepine, and polydrug use. Injecting behavior decreased, employment increased, money spent on drugs fell, criminal activity declined, and suicidal ideation decreased.

However, cannabis and alcohol use remained stubbornly unchanged throughout the 18-month period. This is concerning because these substances can undermine recovery and contribute to their own health problems.

Why it matters

While the overall treatment results are encouraging, the persistence of cannabis and alcohol use raises a red flag. Treatment programs focused on heroin may inadvertently allow other substance use to continue or even increase, potentially compromising long-term recovery.

The numbers in context

100 participants followed for 18 months. Significant reductions in heroin (p<.001), cocaine (p<.05), benzodiazepines (p<.001), and polydrug use (p<.001). No significant change in cannabis or alcohol use. Suicidal ideation decreased (p<.05).

How the study worked

Longitudinal prospective cohort study with repeated measures at baseline (T0), 9 months (T1), and 18 months (T2). The CIDI was used for psychiatric evaluation, EuropASI for drug abuse assessment, WHO-DAS II for disability, and UCLA-SSI for social support. 100 heroin users were recruited.

What this study cannot tell us

The sample of 100 participants is modest. There was no control group to determine whether improvements were due to treatment versus natural recovery. Attrition over 18 months may have biased results if those doing worst dropped out. The study was conducted in London and may not generalize to other healthcare systems.

How to read the evidence

Longitudinal cohort study without a control group; moderate evidence for treatment outcomes.

When this study was published

Published in 2012. Integrated substance use treatment approaches have continued to develop.

The bigger picture

This study illustrates a common pattern in addiction treatment: successful reduction of the primary substance does not automatically translate to reduced use of other substances. Cannabis and alcohol may serve as substitute coping mechanisms or may simply not be addressed by heroin-focused treatment protocols.

Questions still open

• Should heroin treatment programs explicitly address cannabis and alcohol use? Does continued cannabis or alcohol use predict relapse to heroin? Would integrated treatment addressing all substances produce better overall outcomes?

Common questions

Read the original research

Impact of an 18-month, NHS-based, treatment exposure for heroin dependence: results from the London Area Treat 2000 Study.

The American journal on addictions, 21(3), 268-73

Citation

Schifano, Fabrizio; Martinotti, Giovanni; Cunniff, Anna; Reissner, Volker; Scherbaum, Norbert; Ghodse, Hamid. (2012). Impact of an 18-month, NHS-based, treatment exposure for heroin dependence: results from the London Area Treat 2000 Study.. The American journal on addictions, 21(3), 268-73. https://doi.org/10.1111/j.1521-0391.2012.00226.x

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