UC San Diego

Background: Cannabis use and cannabis use disorder (CUD) have become increasingly prevalent, with a notable rise in the United States due to legalization and greater accessibility. Moreover, there is a growing interest in cannabis use among older adults, who often turn to it form medicinal purposes. However, the association between cannabis use and mental health in older adults remains complex and requires further investigation to better understand if cannabis could have potential therapeutic benefits. Understanding these dynamics is crucial for informing policy and clinical interventions, including formulating guidelines for use and early interventions. The goal of this dissertation is to better understand the relationship between cannabis and mental health in middle-aged and older adults via the following three aims (chapters). Methods: Chapter 1- A scoping review was conducted on the existing literature to synthesize current research on cannabis use and depression or anxiety in middle-aged and older adults. Secondary analyses were conducted in chapters 2 and 3 with data from the National Epidemiological Survey on Alcohol and Related Conditions-III (NESARC-III) to investigate the relationship between cannabis use and mental health in middle-aged and older adults. Chapter 2- A logistic regression analyses was run to examine the association between a diagnosis of mood or anxiety disorder and cannabis use disorder controlling for sex, race/ethnicity, education, physical health, heavy alcohol use, tobacco use, and other drug use. Chapter 3- A zero inflated negative binomial regression model was run including interaction terms for sex, heavy alcohol use, other drug use, and tobacco use. All analyses use an alpha of .05. Results: Our scoping review revealed an unclear association between cannabis use and depression or anxiety in middle-aged and older adults, with a multitude of articles reporting different associations. Findings from our two analytical aims found a positive association between lifetime diagnosis of depression or anxiety and cannabis use disorder, as well as cannabis use frequency. This relationship was also shown to be partially moderated by sex, alcohol use, other drug use, and tobacco use. Conclusions: Our results have potential to inform clinicians and the need to be vigilant in screening older adults for cannabis use and mental health disorders and make attempts to understand the different dynamics of cannabis use.