A consumer’s guide to research on substance use disorders (part 4)

In previous posts, I explained the challenges of making sense of research and introduced 8 questions that will help readers evaluate evidence and relevance to their work, goals, and lives. Today is question #3.

3) How long was the study? 

Robert DuPont once observed, “The most striking thing about substance abuse treatment is the mismatch between the duration of treatment and the duration of the illness.” 1

Addiction is a chronic disease and recovery is a long term process, but research is often limited to days and weeks.

The longer the study, the better. For example, Dennis, Foss and Scott 2 found relapse rates of 64% for people between 1 and 12 months abstinent. Those relapse rates drop to 34% for people with between 1 and 3 years abstinent. 

Therefore, a study that reports on any outcome at less than one year may say very little about what can be expected long term.

Look for studies that report on outcomes after one year.


  1. DuPont R. (March, 2018). Interview with Brian Coon. Interview presented at the NC Recovery Alliance Summit, Durham, NC.
  2. Dennis, M. L., Foss, M. A., & Scott, C. K. (2007). An Eight-Year Perspective on the Relationship Between the Duration of Abstinence and Other Aspects of Recovery. Evaluation Review, 31(6), 585–612.

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