Graduate Program

Clinical Psychology

Degree Name

Master of Arts (MA)

Semester of Degree Completion


Thesis Director

John B. Best

Thesis Committee Member

Ronan S. Bernas

Thesis Committee Member

Wesley D. Allan


The Big Five have shown to be distinct personality traits that do not overlap and have universal applicability, so this study examined whether there are specific personality trait differences in users of Marijuana, Pain Medication, Sedative/Hypnotics, and Stimulants.

Study was placed in the 50 most visited Craigslist pages in the United States. Anonymous web users (N = 547) were recruited through Craigslist. High Neuroticism was associated with Marijuana and Stimulant use. Low Conscientiousness was associated with Marijuana and Stimulant use. High Extraversion was associated with Pain Medication use only. Implications, limitations, and suggestions for future research were discussed.