Trajectories of cannabis use beginning in adolescence associated with symptoms of posttraumatic stress disorder in the mid-thirties

ABSTRACT

Background: Posttraumatic stress disorder (PTSD) symptoms are related to a number of adverse consequences such as substance use and general medical conditions. The present longitudinal study seeks to find the longitudinal patterns of cannabis use as precursors of PTSD symptoms. Such information will serve as a guide for intervention programs for PTSD. Methods: Growth mixture modeling was conducted to identify the cannabis use trajectory groups using a community sample of 674 participants (53% African Americans, 47% Hispanics of Puerto Rican decent; 60% females) from the Harlem Longitudinal Development Study. Logistic regression analyses were performed to examine the association between earlier trajectories of cannabis use (ages 14 to 36) and later symptoms of PTSD (at age 36) for the full model including the entire sample (N = 674) as well as the reduced model including only participants who had experienced a traumatic event (n = 205). Results: Five trajectory groups of cannabis use were obtained. The chronic use group (full model: adjusted odds ratio [AOR] = 4.68, P < .01; reduced model: AOR = 4.27, P < .05), the late quitting group (full model: AOR = 6.18, P < .01; reduced model: AOR = 6.67, P < .01), and the moderate use group (full model: AOR = 3.97, P < .01; reduced model: AOR = 3.32, P < .05) were all associated with an increased likelihood of having PTSD symptoms at age 36 compared with the no use group. Conclusions: The findings provide information that PTSD symptoms in the mid-30s can possibly be reduced by decreasing membership in the chronic cannabis use trajectory group, the late quitting trajectory group, and the moderate cannabis use trajectory group.

KEYWORDS:

• Cannabis use
• longitudinal study
• posttraumatic stress disorder symptoms
• trajectory analysis

Additional information

Funding

This research was supported by the following grants from the National Institutes of Health: K01 DA041609–01A1 awarded to Dr. Lee and DA05702 awarded to Dr. J. S. Brook, both from the National Institute on Drug Abuse. The funding organizations had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. The authors declare that they have no conflicts of interest.