A study in the journal Addictive Behaviors examined the underlying factors associated with reductions in drinking and alcohol-related problems among DESC clients. Motivation to change was consistently associated with improved alcohol outcomes, whereas treatment attendance was not. One implication is for more focus on enhancing client motivation to change rather than simply insisting on treatment attendance. See:
Motivation to change and treatment attendance as predictors of alcohol-use outcomes among project-based Housing First residents – Addictive Behaviors (Volume 37 | Issue 8 August 2012)