Introduction: Approximately 4% of the UK population experiences PTSD. Individuals must exhibit symptoms across four clusters to receive a diagnosis: intrusion, avoidance, altered reactivity, and altered mood. Evidence suggests that cannabinoid agonists such as nabilone and tetrahydrocannabinol (THC) may alleviate PTSD symptoms. We investigated the safety and effectiveness of THC-predominant cannabis flowers for inhalation to manage PTSD symptoms in a real-world setting.

Methods: We analysed data from the UK patient registry, T21. Validated questionnaires were used to collect PROMs for health-related quality of life (HRQoL), mood/anxiety, sleep, and PTSD-specific symptoms. Inclusion criteria were (i) a confirmed diagnosis of PTSD, (ii) completed PROMs questionnaires at baseline and at the 3-month follow-up, and (iii) received a prescription for a chemotype 1 (THC-predominant) cannabis flower.

Results: Fifty-eight patients were included, 34 of which also had PROMs recorded at 6 months. Most were males (65.5%) with an average age of 39.2 years who had previously used cannabis illicitly (95.6%). At 3 months, participants reported significant improvements in overall health, mood, and sleep quality (p < 0.001) but not in the proxy for HRQoL (p = 0.052). Similarly, participants reported substantial benefits in managing intrusion symptoms (p < 0.001), mood alterations (p < 0.001), and reactivity alterations (p = 0.002), which were sustained or further improved at 6 months. Participants did not report any side effects associated with CBMPs.

Conclusions: Inhalation of THC is well tolerated and useful for managing symptoms of PTSD in cannabis-experienced individuals. However, further research is needed to evaluate the long-term safety and outcomes of controlled inhalation of CBMP in patients naïve to cannabis.