Smyth BP, et al. - An estimation was conducted of the changes in drug use among adolescents receiving opioid substitution treatment (OST). Experts analyzed the treatment attrition during the first 12 months of this treatment. Eligible candidates included all heroin-dependent patients aged under 18.5 years commencing OST at 1 outpatient multidisciplinary adolescent addiction treatment service in Dublin, Ireland. Substantial reductions in heroin use were reported within 3 months of starting OST among heroin-dependent adolescent patients. This improved further after a year of treatment, about half being heroin abstinent at that stage. It was deduced that the patient drop out from treatment was challenging, as in the case of adults. Findings unveiled that the cocaine use before and during treatment could serve as a negative prognostic factor.