Directional associations between cannabis use and anxiety symptoms from late adolescence through young adulthood

Abstract

Background: Two major theories aid in explaining the association between anxiety and cannabis use: a symptom-driven pathway (heightened anxiety precedes greater cannabis use) and a substance-induced pathway (greater use precedes heightened anxiety). Although the co-occurrence of cannabis use and anxiety symptomology is well-established, less is known about the temporal sequence of cannabis use and anxiety symptomology over the course of young adult development METHODS: Data are from an ongoing, longitudinal, cohort study. All prospective analyses used data from wave 8, when participants were between the ages of 17 and 20, through wave 13, when participants are between ages 21 and 24 (N = 2995). Data were set up in accelerated longitudinal design in which we estimated a series of latent difference score models between anxiety and cannabis use from 17 to 24 years old. Models were estimated for men and women, separately.

Results: For the overall sample and men, greater cannabis use predicted greater subsequent increases in anxiety; however, greater anxiety symptoms were associated with decreasing cannabis use. For women, results were more complex. A positive association was noted between prior, trait-like levels of anxiety predicting greater change (increasing) in anxiety symptomology. However, when change is predicted by prior change we see that cannabis use decreases among women who have recently experienced an increase in anxiety CONCLUSION: The nuanced set of results from this study support a dynamic interplay between anxiety symptoms and cannabis use, with important sex differences observed. Overall, our results pave the way for rethinking our guiding theories to include a more robust, flexible, and dynamic model for understanding associations between substance use and mental health symptomology during a key period of development.

Keywords: Anxiety disorder; Emerging adult; Longitudinal; Psychopathology; Sex differences; Substance Use Treatment; Trauma.

Figure 1.

Conceptual latent difference score model for anxiety and cannabis use. Note: conceptual model stops at age 20 for visual purposes only. The full model extends to 24 years old. Lagged effects labeled with the δ symbol represent proportional coupling parameters. Lagged effects labeled with the ξ symbol represent dynamic coupling parameters.

Figure 2

a. Effect of forced changes in cannabis use on anxiety from 17 to 24 years old for the full sample. Predicted trajectories for a hypothetical young adult who begins with average levels of anxiety and cannabis use (i.e., intercept values) at age 17. We then provide “system shocks” to cannabis use to understand the effect on anxiety symptoms over time. b. Effect of forced changes in anxiety on cannabis use from 17 to 24 years old for the full sample. Predicted trajectories for a hypothetical young adult who begins with average levels of anxiety and cannabis use (i.e., intercept values) at age 17. We then provide “system shocks” to anxiety symptoms to understand the effect on cannabis use over time.

Figure 2

a. Effect of forced changes in cannabis use on anxiety from 17 to 24 years old for the full sample. Predicted trajectories for a hypothetical young adult who begins with average levels of anxiety and cannabis use (i.e., intercept values) at age 17. We then provide “system shocks” to cannabis use to understand the effect on anxiety symptoms over time. b. Effect of forced changes in anxiety on cannabis use from 17 to 24 years old for the full sample. Predicted trajectories for a hypothetical young adult who begins with average levels of anxiety and cannabis use (i.e., intercept values) at age 17. We then provide “system shocks” to anxiety symptoms to understand the effect on cannabis use over time.

Figure 3.

Effect of forced changes in cannabis use on anxiety from 17 to 24 years old for men and women. Predicted trajectories for a hypothetical young adult who begins with average levels of anxiety and cannabis use (i.e., intercept values) at age 17. We then provide “system shocks” to cannabis use to understand the effect on anxiety symptoms over time. a. Hypothetical Man b. Hypothetical Woman

Figure 3.

Effect of forced changes in cannabis use on anxiety from 17 to 24 years old for men and women. Predicted trajectories for a hypothetical young adult who begins with average levels of anxiety and cannabis use (i.e., intercept values) at age 17. We then provide “system shocks” to cannabis use to understand the effect on anxiety symptoms over time. a. Hypothetical Man b. Hypothetical Woman

Figure 4.

Effect of forced changes in anxiety symptoms on cannabis use from 17 to 24 years old for men and women. Predicted trajectories for a hypothetical young adult who begins with average levels of anxiety and cannabis use (i.e., intercept values) at age 17. We then provide “system shocks” to anxiety symptoms to understand the effect on cannabis use over time a. Hypothetical man b. Hypothetical Woman

Figure 4.

Effect of forced changes in anxiety symptoms on cannabis use from 17 to 24 years old for men and women. Predicted trajectories for a hypothetical young adult who begins with average levels of anxiety and cannabis use (i.e., intercept values) at age 17. We then provide “system shocks” to anxiety symptoms to understand the effect on cannabis use over time a. Hypothetical man b. Hypothetical Woman