Attention-deficit/hyperactivity disorder (ADHD) is characterized by multiple symptoms related to either hyperactivity/impulsivity or inattention and significant impairment. College students with ADHD experience greater impairment than their typical peers, including substance use behaviors. Although the use of alcohol, tobacco, and illicit drugs is a normative experience of emerging adulthood, as rates of mental health disorders rise among college students, it is important to better understand the relationship between psychological distress (e.g., anxiety, depression) and substance use behaviors. This study sought to examine whether anxiety, depression, and quality of life in first year college students predicted second year substance use; or substance use behaviors of first year college students predicted second year anxiety, depression, and quality of life; and whether these patterns differed between college students with and without ADHD. Results demonstrated that tobacco use in first year of college was associated with increased depressive and anxious symptoms; depressive symptoms in first year of college were associated with increased cannabis use in second year of college; and anxiety symptoms in first year of college were associated with decreased tobacco use in second year of college. There were significant group differences between the ADHD and control groups in the relationship between first year anxiety and second year cannabis use and first year tobacco use and second year anxiety symptoms. Additional research is warranted to better understand these differences and further examine variables (e.g., gender, treatment for ADHD, anxiety, and depression) that may be stronger predictors of both psychological distress and substance use. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]