Computer-based motivational intervention reduced marijuana use via concerns about relationships | Research

The takeaway

A computer-delivered brief intervention in an emergency department reduced marijuana use at 6 months, with the most effective component being items about concerns regarding family and friends, which predicted up to 5.5 fewer days of use per month.

Emergency department clinicians, intervention designers, and people considering reducing cannabis use.

Up to 5.5 fewer use days from relationship concern items

What the researchers found

The "evoking-change" domain (concerns about use and benefits of change) was significantly associated with reduced marijuana use at 6 months (B=-2.91, p<0.01). Within this domain, items about concerns regarding family and friends predicted the largest reduction: up to 5.5 fewer days of marijuana use per month (B=-5.49, p<0.01).

Why it matters

Computer-delivered interventions are scalable, low-cost, and can be delivered in busy settings like emergency departments. Knowing which components work allows for more efficient intervention design.

The numbers in context

237 ED patients. 46% male. 54% African-American. Mean age 30.7. Evoking-change domain: B=-2.91, p<0.01. Family/friend concerns: up to 5.5 fewer days/month (B=-5.49, p<0.01). 6-month follow-up.

How the study worked

Secondary analysis of 237 emergency department patients reporting recent drug use who received a computer-based brief intervention with a virtual health counselor. Five motivational interviewing domains were examined as predictors of past 30-day marijuana use at 6-month follow-up.

What this study cannot tell us

Secondary analysis of a trial designed to test the overall intervention, not individual components. Self-reported marijuana use. Single urban ED. Component analysis may have limited statistical power.

How to read the evidence

Secondary analysis of a randomized trial with 6-month follow-up, though not designed to test individual components.

When this study was published

2019 study.

The bigger picture

The finding that relationship concerns drive behavior change more than other motivational factors aligns with broader addiction research showing social connections are powerful motivators for change.

Questions still open

Would a brief intervention focused exclusively on relationship concerns be equally effective? Does this approach work for heavier users?

Common questions

Can a computer program help people reduce marijuana use?

This study found that a computer-based motivational interview in an emergency department reduced marijuana use at 6 months, particularly when it prompted people to think about how their use affected family and friends.

What motivates people to reduce marijuana use?

Concerns about the impact on family and friends were the strongest predictor of reduced use, more so than other motivational domains like goals, strengths, or tools for change.

Read the original research

Exploring the components of an efficacious computer brief intervention for reducing marijuana use among adults in the emergency department.

Journal of substance abuse treatment, 99, 67-72

View on PubMed ↗Publisher’s paper ↗

Citation

Waller, Rebecca; Bonar, Erin E; Fernandez, Anne C; Walton, Maureen A; Chermack, Stephen T; Cunningham, Rebecca M; Blow, Frederic C. (2019). Exploring the components of an efficacious computer brief intervention for reducing marijuana use among adults in the emergency department.. Journal of substance abuse treatment, 99, 67-72. https://doi.org/10.1016/j.jsat.2019.01.014