Correction

In the article “Internet-Delivered Treatment for Substance Abuse: A Multisite Randomized Controlled Trial,” by Aimee N.C. Campbell et al. (Am J Psychiatry 2014; 171:Original article: 683–690), in the Method section, the authors stated that abstinence was defined as no evidence of drug use (negative self-report and negative urine screen) and no heavy drinking days (no days drinking above the public health criterion for at-risk drinking of >3 drinks per day for women, >4 drinks per day for men). However, the authors now report that the analyses reported in the article were based on the criterion of “no evidence of drug use and no drinking days.” The authors found that an additional 1.8% of half weeks should have been classified as abstinent using the definition of no evidence of drug abuse and no heavy drinking days. This reclassification does not result in a change in the effect of the treatment.