Author ORCID Identifier
https://orcid.org/0000-0001-8684-2492
Defense Date
2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Clinical Psychology
First Advisor
Dace Svikis, Ph.D.
Second Advisor
Leila Islam, Ph.D.
Abstract
Research has found significantly higher rates of both substance use and obesity among individuals with SMI compared to population samples which in turn can lead to worsening health outcomes. Despite this, there is limited research on the co-occurrence of obesity, substance use, and SMI and how these conditions may interact to affect patient outcomes. In addition, there are many gaps in the research regarding the relationship between substance use and body weight, appetite and/or eating behaviors. This study conducted a secondary analysis of the NSDUH 2021 survey that characterized substance use and disorders among individuals who had severe psychopathology, examined differences between those with and without comorbid obesity, and examined how substance use variables impacted treatment engagement and satisfaction. Rates of substance use disorders were consistently elevated in our sample, similar to rates in the literature. Participants with obesity had significantly lower average alcohol use frequency in both the past month and the past year, but there were no significant differences in alcohol quantity or frequency of alcohol use disorder. There were no significant differences in cannabis related variables. Participants with obesity were more likely to report a history of smoking 100+ cigarettes, daily smoking, and nicotine dependence in the past year. Individual substance use variables were not significant predictors of treatment engagement and satisfaction, but gender was a significant predictor within all of our models. This gender effect was the most pronounced in the Perceived Unmet Need/Received Treatment group, where men had on average 64% lower odds of group membership, compared to the reference group (No Perceived Unmet Need/No Mental Health Treatment). Present study findings can inform future research to better understand the relationships between body weight, psychopathology, and substance use.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
5-1-2026