Examining Substance Use Treatment Efficacy at 12-Month Follow-Up, Across Younger and Older Adults

The article we will discuss this week is published in the Journal of Addictive Behaviors, and is titled “Evaluating substance use treatment efficacy for younger and older adults.”  In this article, authors Dingle and Bowen examine how common substance use treatments - standard cognitive-behavioral relapse prevention (RP), Mindfulness-Based Relapse Prevention (MBRP), and 12-step-based treatment as usual (TAU) - are associated with 12-month sobriety for younger and older adults.

Why did they do it?

In the United States alone there are approximately 20 million individuals over age 12 who meet criteria for a substance use disorder. Importantly, emerging adults seem to be disproportionately represented in this statistic. The authors explain that 14.8% of emerging adults meet criteria for substance use disorder, versus 6.4% of those individuals age 26 and older. Additionally, it is estimated that 15.2% of emerging adults require substance use treatment versus 6.8% of individuals age 26 and older. Ultimately, the authors clearly indicate the presence of age-based differences with regard to outcomes of younger and older adults who have substance use disorders. 

While much is known about age-related differences in substance use more generally, there has been little research examining age-related differences with regard to longer term treatment efficacy. Within the scarce research published on this topic, it has been suggested that there are in fact distinct populations (i.e., younger versus older adults) with different treatment needs. In order to expand on this area of relatively limited knowledge, the authors of this study assessed differential outcomes following three treatment approaches in younger (<40) versus older (40+) adults.

How did they do it?

This study utilized data from a randomized controlled trial (n = 221) in community based substance use aftercare. The study included participants between the ages of 19 and 62 years old with a substance use duration of at least 12 months. Self-report measures including the Timeline Followback (TLFB), which assesses estimated substance use over the past year, and the Severity of Dependence Scale (SDS), which assesses severity of dependence using a 4-point scale, were administered as a part of the original trial. 

Data were split into younger (<40) and older (40 + ) subsamples, with the younger subsample (YA; n = 107) representing an average age of 29 years, while the older subsample (OA; n = 114) had an average age of 48 years. 

The authors used exploratory analyses to assess between and within-group differences in 12-month abstinence rates.

What did they find?

There were no statistically significant between-group (YA vs. OA) differences in 12-month abstinence rates. Additionally, there were no statistically significant within-group differences with regard to 12-month abstinence rates in YAs. 

There were statistically significant within-group differences in OAs. Specifically, it was found that OAs in the TAU group had significantly lower abstinence rates when compared to OAs in the MBRP group. No other between-group/treatment effects were observed. Additionally, the authors found that age group significantly predicted percent use days over the 12-month follow-up, such that the incident rate ratio of days used in YAs was 1.77 times the rate of OAs. 

What does it all mean (our take)?

As the world of behavioral health grows, we are learning that our ability to develop idiographic treatment plans is critically important. The authors of this study importantly demonstrated that customizing treatment plans based on age, particularly for a substance abuse population, could prove to return significantly improved patient outcomes. We appreciate this great work from the authors and feel that this is a highly substantial contribution to the substance abuse literature. At the end of the day, we believe it is work like this that will lead to significant improvement in patient long term outcomes, not just within the substance abuse world, but the world of behavioral health more broadly.