Theses and Dissertations

Date of Award


Document Type


Degree Name

Doctor of Psychology (PhD)


Center for Psychological Studies

First Advisor

Mark B Sobell

Second Advisor

Linda C Sobell

Third Advisor

Craig Marker


Alcohol, Growth Mixture Modeling, Longitudinal, Motivational Interviewing, Predictors of Outcome, Problem Drinker


Most studies examining predictors of treatment outcomes among problem drinkers have used a traditional statistical approach that examines group outcomes (e.g. analysis of variance, multiple regression analysis). Contrary to traditional methods, a person-centered approach identifies commonalities among clusters of individuals and provides the opportunity to examine the relationship between multiple individual differences and outcomes in a longitudinal manner. Specifically, the person-centered approach makes it possible to cluster individuals into subgroups based on their change patterns, and to examine the relationship between those subgroups and other variables of interest (e.g., drinking problem severity). This approach allows the inclusion of a relatively large number of variables to test complex hypotheses. The present study is a secondary data analysis of early (first three-month) Timeline Followback (TLFB) post-treatment drinking data from 200 problem drinkers who completed a short outpatient intervention. Using a growth mixture modeling (GMM) analysis, the goal was to identify different outcome drinking trajectories and examine the relationship between problem severity levels, treatment modality (i.e. individual versus group format), and goal choice (i.e. low-risk drinking versus abstinence) to those trajectories. Results demonstrated the existence of different outcome subgroups among problem drinkers. In addition, problem severity level was associated with outcomes and class membership. Observed significant differences in the relationships between predictor variables and specific outcome subgroups, and evidence of different drinking fluctuation patterns in the outcomes suggest that using a person-centered approach adds value beyond traditional statistical outcome analyses. The person-centered approach can facilitate the identification of relevant variables for patient-treatment matching hypotheses for problem drinkers.

  Link to NovaCat

Included in

Psychology Commons