Marijuana Use Is Associated With Worse Outcomes in Symptom Severity and Violent Behavior in Patients With Posttraumatic Stress Disorder

Abstract

Objective: An increasing number of states have approved posttraumatic stress disorder (PTSD) as a qualifying condition for medical marijuana, though little evidence exists evaluating the effect of marijuana use in PTSD. We examined the association between marijuana use and PTSD symptom severity in a longitudinal, observational study. Methods: From 1992-2011, veterans with PTSD (N=2276) were admitted to specialized VA treatment programs with assessments conducted at intake and four months after discharge. Subjects were classified into four groups according to marijuana use: those with no use at admission or after discharge (“never used”); those who used at admission but not after discharge (“stoppers”); those who used at admission and after discharge (“continuing users”); and those using after discharge but not at admission (“starters”). Analyses of variance compared baseline characteristics and identified relevant covariates. Analyses of covariance then compared groups on follow-up measures of PTSD symptoms, drug and alcohol use, violent behavior, and employment. Results: After adjusting for relevant baseline covariates, marijuana use was significantly associated with worse outcomes in PTSD symptom severity, violent behavior, and measures of alcohol and drug use. At follow up, stoppers and never users had the lowest levels of PTSD symptoms (p<0.0001) and starters had the highest levels of violent behavior (p<0.0001). After adjusting for covariates and using never users as a reference, starting marijuana had an effect size on PTSD symptoms of +0.34 (Cohen’s d = change/SD) and stopping marijuana had an effect size of −0.18. Conclusions: In this observational study, initiating marijuana use after treatment was associated with worse PTSD symptoms, more violent behavior and alcohol use. Marijuana may actually worsen PTSD symptoms or nullify the benefits of specialized, intensive treatment. Cessation or prevention of use may be an important goal of treatment.

Marijuana Violence and Law

“…The sense of fear, loss of control, and panic is associated with violence [16][17][18]. Also marijuana use increases heart rate, which may be associated with violent behaviour [19][20][21][22].…”

“…Dear moved to Colorado for easier access to marijuana. Dear also exhibited signs of mental health illness, psychosis and paranoia, which caused or exacerbated by marijuana, which resulted in his shooting spree [18,31].…”

Clinical Factor 2015

“…As an increasing number of states in the USA have approved posttraumatic stress disorder (PTSD) as a qualifying condition for medical marijuana without much evidence of its effect on PTSD, Wilkinson et al [9] decided to examine the association between marijuana use and PTSD symptom severity in a longitudinal observational study. They used data drawn from the national evaluation of specialized intensive PTSD programs implemented by the Northeast Program Evaluation Center of the Veterans Health Administration from 1992 to 2011.…”

“…Nevertheless, the results suggest that more potent cannabis may be associated with a higher degree of dependence and with a higher degree of associated psychopathology. It would be important to examine whether the more potent cannabis plays a larger role in worsening of psychopathology of various mental disorders during cannabis abuse [7,8,9]. (Dr. Freeman's work was supported by the Medical Research Council.…”

Neural mechanisms of sensitivity to peer information in young adult cannabis users

“…It is important to understand motivations for MJ use, as heavy use in adolescence/young adulthood has been robustly linked with harms such as future substance dependence (Berge et al, 2015; Green et al, 2015), worse psychosocial functioning (Lagerberg et al, 2015; Wilkinson, Stefanovics, & Rosenheck, 2015) and worse academic outcomes (Epstein et al, 2015; Meier, Hill, Small, & Luthar, 2015; Silins et al, 2015). Young adults may both initiate and continue to use MJ in part due to social factors.…”