Study results indicate that individuals awaiting charges, trial, or sentencing, who perceive pressure but have not yet entered the penal system, persevere in treatment. Therefore, it is seen as reasonable to believe that the threat inherent in the judicial process does have the impact desired by courts, but has only been observed on the pre-sentencing level. The study also indicates that while pressure has a beneficial impact in that it reduces dropout risk in the short term, at least with individuals subject to pre-sentencing pressure, such perseverance is not necessarily tied to positive treatment impact. Most drug-addicted offenders require services and treatment not provided by the criminal justice system. Numerous studies have shown that offenders successfully exposed to treatment for sufficiently long periods of time obtain beneficial results. This Canadian study examined variables that could predict treatment perseverance and impact for 124 offenders admitted to 1 of 5 rehabilitation centers for alcoholic/drug addicts representing different regions of the province of Quebec. Tables, references