Undergraduate thesis studying anxiety and substance use disorders (SUD) by examining the prevalence of anxiety-SUD comorbidity in an outpatient psychology training clinic and assessing how it affects psychotherapy outcomes. Results revealed that anxiety and SUD is more highly comorbid compared to when anxiety is paired with another disorder and the presence of a comorbid SUD was associated with worse therapy outcomes at the beginning and end of therapy. However, the comorbid SUD did not affect the rate of recovery in patients. Both groups benefited equally from therapy.