The study analyzed the effectiveness of substance abuse rehabilitation from three perspectives using data from 575 patients from two treatment centers. Logistic regression found that older patients and those who received longer treatment at one specific site had lower odds of remaining drug-free after 12 months. Multiple regression determined a model to predict depression scores based on age and drug history, but the model only explained 3% of variation. Longer treatment duration at one site significantly decreased the chances of long-term sobriety. The conclusions were limited by the small number of continuous predictors.