Differences between treatment-seeking and non-treatment-seeking participants in medication studies for alcoholism: do they matter?

Background: Medication development for alcoholism typically includes experimental pharmacology studies with non-treatment-seeking individuals with alcohol use disorder (AUD) paving the way for randomized controlled trials in treatment-seekers with AUD. Objectives: The goal of this study is to provide a direct comparison between AUD treatment-seeking research participants and non-treatment-seeking participants on demographic and clinical variables and to test whether variables that differentiate the two groups are associated with clinical outcomes. Method: Non-treatment-seeking AUD participants (n = 213; 76.3% male) who completed behavioral pharmacology studies were compared to treatment-seekers who completed the COMBINE Study (n = 1383; 69.1% male) on demographic and clinical variables. Analyses examined whether the variables that differentiated the two groups predicted treatment outcomes in the COMBINE Study. Results: Analyses revealed that treatment-seeking participants were older, had more years of education, higher Alcohol Dependence Scale scores, higher Drinker Inventory of Consequences scores, higher Obsessive Compulsive Drinking Scale scores, a greater number of DSM-IV symptoms of AUD, longer duration of AUD, and consumed more standard drinks and more drinks per drinking day (i.e., in the past 30 days) compared to non-treatment-seeking participants. Nearly all characteristics that differed between the groups predicted at least one of the primary clinical outcomes of the COMBINE Study. Conclusions: This study highlights a host of clinical and demographic factors that differ between non-treatment-seeking and treatment-seeking research participants and the clinical significance of these variables. Differences between samples should be considered and addressed in order to promote greater consilience across stages of medication development.