Previous research has established the presence of cognitive impairments in chronic substance abusers. Chronic alcoholics often have measurable deficits in problem-solving, abstract reasoning, motor skills, and memory. While chronic drug abusers tend to be a more diverse population, the overall incidence of cognitive problems in substance abusers can range from 30% to 80%. A study published in a recent issue of Experimental and Clinical Psychopharmacology examine the comparative efficacy of cognitive rehabilitation as an intervention for substance abuse. A sample of 160 patients with substance use disorders entering long-term residential care were randomly assigned to one of two conditions: a: standard treatment plus computer-assisted cognitive rehabilitation (CACR) , which was designed to improve cognitive performance in areas such as problem solving, attention, memory, and information processing speed; and b: an equally intensive attention control condition consisting of standard treatment plus a computer-assisted typing tutorial (CATT). Participants were assessed at baseline, during treatment, at treatment completion, and 3-, 6-, 9-, and 12-month follow-up. Analysis of research results showed that, compared with those randomized to CATT, patients who received CACR were significantly more engaged in treatment e.g., higher ratings of positive participation by treatment staff, higher ratings of therapeutic alliance , more committed to treatment e.g., longer stays in residence and reported better long-term outcomes e.g., higher percentage of days abstinent after treatment . Researchers also found that revealed the positive comparative effect of CACR on abstinence during the year after treatment was mediated by treatment engagement and length of stay in residence. Further research into the precise mechanisms by which cognitive rehabilitation can be used to treat substance use disorders is being planned.