Addiction research by region, substance and gender

Research with the context left in

Explore studies and public-health data by region, substance, sex and gender, or treatment question. Each article identifies the evidence design and data period, explains the main finding and separates it from our interpretation. This is a selected educational collection, not a systematic review of all addiction research.

A surveillance report describes a population or service. A trial tests an intervention in a defined sample. Neither automatically ranks a treatment provider or predicts one person’s outcome.

Region

• Cocaine in Europe: what the 2026 evidence shows

  Read Europe’s cocaine evidence across seizures, treatment and wastewater, with the data years and limits that matter when interpreting regional trends.

• Substance use in Spain: age and sex in EDADES 2024

  Explore Spain’s EDADES 2024 findings for alcohol, cannabis and sedatives, including age and sex differences and why reported use is not an addiction diagnosis.

• Heroin-assisted treatment in Switzerland: the evidence

  Understand Switzerland’s supervised diacetylmorphine programme, the outcomes it monitors and why its evidence cannot be used to rank private rehabs.

• Addiction treatment in England: reading the 2024–25 data

  See who accessed addiction treatment in England in 2024–25, including age, sex and substance groups, and what service records cannot tell us about unmet need.

• US overdose data: how to read provisional trends

  Learn how CDC provisional overdose counts differ from final totals, why reporting delays matter, and how to compare US trends without overstating the evidence.

Substance

• Cannabis potency and psychosis: what EU-GEI found

  Understand the EU-GEI study on daily cannabis use, THC potency and psychosis, including odds ratios, uncertainty and the limits of observational evidence.

Sex & gender

• Women and addiction treatment: barriers in the research

  Explore research on women’s access to addiction treatment, including caring responsibilities, stigma and trauma, with clear limits on gender-wide conclusions.

Treatment evidence

• Contingency management for cocaine: the evidence

  Review the evidence for contingency management in cocaine treatment, what trials measured, and the practical questions to ask about a programme.

• Alcohol medications: what the research supports

  Explore evidence for alcohol-use-disorder medications, including naltrexone and acamprosate, and learn how to interpret benefits, uncertainty and treatment fit.

• Opioid treatment retention and mortality: the evidence

  Read cohort evidence on mortality during and after opioid medication treatment, with clear limits on comparisons and practical questions about continuity of care.

Research methods

• Rehab success rates: how to evaluate the evidence

  Learn to assess rehab success claims by checking outcomes, denominators, follow-up and missing data, with a worked example and questions for providers.

Emerging research

• GLP-1 medicines and alcohol: the 2025–26 trials

  Compare two semaglutide trials in alcohol use disorder, including their populations, outcomes and limitations, without confusing early evidence with a treatment plan.

How to use a research article

Start with the question and population, then read the result and limitations together. Keep the data year with a statistic. If an article discusses treatment, use its questions to prepare for a qualified assessment. For immediate safety concerns, use urgent-help resources.

Read the editorial standards or report a correction if a source, date or interpretation needs attention.