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Updated: Apr 28, 2026

Administration of Δ9-Tetrahydrocannabinol (THC) in Adolescent and Adult Mice
Published on: August 1, 2025
Preliminary, open-label, pilot study of add-on oral Δ9-tetrahydrocannabinol in chronic post-traumatic stress disorder
Pablo Roitman1, Raphael Mechoulam, Rena Cooper-Kazaz
1Department of Psychiatry, Hadassah Hebrew University Medical Center, Jerusalem, Israel, pabloroitman36@gmail.com.
Background And Objectives:
Many patients with post-traumatic stress disorder (PTSD) achieve but partial remission with current treatments. Patients with unremitted PTSD show high rates of substance abuse. Marijuana is often used as compassion add-on therapy for treatment-resistant PTSD. This open-label study evaluates the tolerance and safety of orally absorbable Δ(9)-tetrahydrocannabinol (THC) for chronic PTSD.
Methods:
Ten outpatients with chronic PTSD, on stable medication, received 5 mg of Δ(9)-THC twice a day as add-on treatment.
Results:
There were mild adverse effects in three patients, none of which led to treatment discontinuation. The intervention caused a statistically significant improvement in global symptom severity, sleep quality, frequency of nightmares, and PTSD hyperarousal symptoms.
Conclusions:
Orally absorbable Δ(9)-THC was safe and well tolerated by patients with chronic PTSD.

