BACKGROUND: Many studies address the different treatments for crack cocaine use disorder without distinguishing between crack use and cocaine use disorder. Furthermore, they highlight various approaches, such as psychotherapeutic methods, medications and social interventions, whose effectiveness remains contentious for crack use disorder. Our aim is to evaluate the relative effectiveness of these various treatments specifically for crack use disorder.

METHODS: This systematic review followed PRISMA guidelines, we searched Web of Science, Psychinfo and Web of Science for studies between 2014 and july 2024. Eligigibility criteria : Due to the limited number of available studies, we included all studies worldwide with full text available in English or French, published between 2014 and 2024, reflecting the recent increase in interest in crack use. Studies included adults aged 18 years or older with a clinical diagnosis of crack cocaine addiction based on a validated clinical scale. We excluded studies that did not distinguish between crack and cocaine use in their assessment of crack cocaine (or crack/cocaine) use disorder. We reported the randomized controlled trials results based on the type of interventions, including various outcomes: reduction of health and social harm, increased accessibility and retention in healthcare, and reduction in drug use. The reliability of the evidence was assessed using Cochrane's tool for evaluating the risk of bias.

RESULTS: We identified 3,313 records, of which 46 were eligible, and 33 were finally included. Among the 33 studies, 15 were randomized controlled trials (RCTs). Among the RCTs, the majority had a moderate risk of bias (8/15), followed by high risk (6/15), and only one had a low risk of overall bias. Contingency management demonstrated significant results in improving abstinence rates, treatment retention, and mental health outcomes. Pharmacological trials showed variable results, though dexamfetamine demonstrated some promise in reducing drug use. Adjunct trials highlighted the potential of transcranial direct current stimulation to improve abstinence rates and quality of life.The other studies collectively underscored the effectiveness of adjunct therapies, case management, peer engagement, outreach, and safer smoking places in addressing substance use, treatment retention and improving related health outcomes. The findings highlight that tailored interventions supported by contingency management approach, enhance engagement and treatment effectiveness.