German Study Finds Cannabis-Derived Dronabinol Significantly Reduces Nightmares in PTSD Patients

Aug 5, 2026

A clinical trial conducted by researchers at Charité – Universitätsmedizin Berlin reveals that the cannabis-derived drug dronabinol significantly reduces trauma-related nightmares in PTSD patients. In the 10-week double-blind study of over 170 participants, more than one-third of those taking dronabinol reported their nightmares disappeared entirely, and five out of six felt their health markedly improved. The treatment did not alleviate other PTSD symptoms like depression, but it caused no severe side effects or withdrawal symptoms.

Dronabinol efficacy for PTSD nightmares

▪A 10-week double-blind, placebo-controlled study of over 170 PTSD patients found that dronabinol significantly reduced nightmare burden compared to a placebo.
▪Five out of six patients in the dronabinol group reported that their health had markedly improved.
▪More than one-third of PTSD patients treated with dronabinol reported no nightmares after 10 weeks, and 21% reported their nightmare burden was halved.
▪Dronabinol did not significantly change other PTSD symptoms, such as the severity of the disorder or accompanying depression.
▪Patients taking dronabinol experienced no severe side effects or withdrawal symptoms, though some reported mild to moderate side effects like dizziness, headache, or increased appetite.

PTSD sleep disturbances

▪Post-traumatic stress disorder causes overwhelming memories to resurface at night, leading patients to repeatedly relive trauma in intense nightmares and wake up in panic.
▪Interrupting tormenting nightly nightmares allows post-traumatic stress disorder patients to achieve restful sleep.

Endocannabinoid system in PTSD

▪Evidence suggests tetrahydrocannabinol reduces dream activity during REM sleep, thereby alleviating nocturnal stress responses.
▪Tetrahydrocannabinol interacts with the body's endocannabinoid system, which regulates sleep, stress, and the processing of emotional memories.

Current PTSD pharmacotherapy limitations

▪Prior to the study, no medication specifically for treating trauma-related nightmares had been approved in Germany.
▪Antidepressants and blood pressure-lowering medications are commonly used for post-traumatic stress disorder but are only partially effective and usually do not relieve nightmares.
▪Germany's 2017 "Cannabis for medical purposes" law made it easier to use plant-derived or synthetic cannabinoids for medical and scientific purposes.