Cannabis promising treatment for post-traumatic stress, evidences is lacking
As growing numbers of people are using cannabis to treat post-traumatic stress disorder (PTSD), though prescriptions are not backed up by adequate evidence, according to a new study by the University College London in England and published in the Journal of Dual Diagnosis.
Cannabinoids, the active ingredients of cannabis, which include tetrahydrocannabinol (THC) and cannabidiol (CBD), may be helpful at treating PTSD as they can change how the brain processes memories. The cannabinoids act on the brain's built-in endocannabinoid system, which also regulates other brain functions that are affected by PTSD.
The research team conducted a systematic review of all studies where someone with a PTSD diagnosis has been using a cannabinoid to reduce their symptoms, and they assessed the quality of each study. They found 10 studies that met their criteria, which cover a range of products including smoked cannabis, THC and CBD separately in oil or pill form, and a synthetic cannabinoid called nabilone.
Every study had medium to high risk of bias, and all were assessed as low in quality due to limitations such as small sample size, retrospective study design, lack of a control group or placebo, short follow-up periods, and not reporting other medication use or addiction. Only one study was a randomized controlled trial, investigating nabilone, but it was in a small sample over a relatively short period of time, according to the study abstract.
The review found that the cannabinoids may hold promise as a treatment for PTSD, particularly for reducing nightmares and helping people sleep, but more research is needed to determine whether these drugs should be used in routine clinical practice.
PTSD is a potentially debilitating condition affecting roughly 3.5 percent of U.S. adults, according to the American Psychiatric Association. PTSD is characterized as reexperiencing a traumatic event through intrusive memories, flashbacks or nightmares, and often involves hyperreactivity and insomnia.
Psychotherapies including trauma-focused cognitive behavioral therapy have been shown to be effective for PTSD. However, not everyone can access talking therapies and they do not work for everyone, so many people still need to take prescribed medications. Existing drugs approved for PTSD do not work for everyone, and can have side effects, so researchers say there is an urgent need to identify new treatments.
The researchers say there are still many unanswered questions about the safety and efficacy of cannabis-based medications for PTSD, and potential long-term effects such as addiction or a risk of psychosis. The existing evidence shows promise, however, as some studies showed that cannabis products appeared to reduce PTSD symptoms such as insomnia and nightmares, according to Michael Bloomfield, PhD, the study’s senior author.
"Based on the evidence, we cannot yet make any clinical recommendations about using cannabinoids to treat PTSD,” he said in a statement. “Current prescribing of cannabinoids for PTSD is not backed up by high quality evidence, but the findings certainly highlight the need for more research, particularly long-term clinical trials."