Virginia Thornley, M.D., Neurologist, Epileptologist
March 28, 2018
Post-traumatic stress disorder occurs due to a single or a sequence of traumatic events which causes a great deal of anxiety when exposed to situations similar to the event. Flashbacks and nightmares may occur. In military veterans returning from the Iraqi or war in Afghanistan and even to this day in Vietnam War veterans, emotional disruption is noticeable. It is difficult to know if this is related to blast injury or is a symptom of post-traumatic stress disorder.
PTSD correlated with mild traumatic brain injury
In a retrospective study reviewing medical records of 27,169 military personnel of the U.S. Army Special Operations Command (USASOC), 2831 met criteria of mild traumatic brain injury using the Immediate post-concussion assessment cognitive test, PTSD checklist, and the post-concussion symptom scale. Of these, 28% exhibited symptoms of post-traumatic stress disorder. Military veterans of blunt, blast or a combination injury had a higher percent of meeting criteria for post-traumatic stress disorder than those without mild traumatic brain injury. Those with blast/combination injury had a higher percent of post-traumatic stress disorder and performed worse with visual memory and time for reacting compared the cohort without any blunt or mild traumatic brain injury. Repetitive exposure to blast-type injuries may have a lingering effect (2). This study found a high degree of PTSD symptoms in those with blast, blunt and combination injury compared to the cohort without it.
In a study, disrupted emotional responses correlate with PTSD rather than blast-related traumatic brain injury
Another study tried to dissect whether the emotional responses of war veterans are due to PTSD or due to the mild brain injury itself. In one study of 123 military veterans from the war in Iraq and Afghanistan, affective evaluations and psychological assessments were made in response to pleasant, neutral, unpleasant and war-related images. Those with emotional disruption due to PTSD rated pleasant images as unpleasant and had increased physiological responses towards combat-related images. Symptoms of post-traumatic stress disorder included increased skin conductance responses, greater corrugator muscle electromyography responses, and reduced heart decelerations. There were no effects noted in veterans with mild traumatic brain injury. This points towards the emotional disruption seen in military veterans as related with post-traumatic stress disorder rather than due to the mild traumatic brain injury itself. This study may help guide treatment as military veterans transition to civilian life (1).
Medical marijuana and mechanism of action, a non-intoxicating solution when cannabidiol is used alone or in conjunction with low dose tetrahydrocannabinol
Cannabidiol is a non-intoxicating endocannabinoid that works within the endocannabinoid system found naturally in our systems. It has only a weak affinity to the CB1 receptor which is found abundantly within the neurological system. CB1 receptors are found to be increased in response to cerebral cell damage and seem to work as a repair mechanism for neural systems that are not functioning. Tetrahydrocannabinol at low concentrations has medical properties without the intoxication of high dose THC. THC should be used in combination with CBD to offset the possible side effects such as hyperactivity.
There are increasing studies showing the value of medical marijuana, especially in the central nervous system especially given the large abundance of the CB1 receptor within the nervous system. The receptors are found to be upregulated in the face of disease suggesting a cell repair role or a response to the abnormalities within the brain, For example, in patient with seizures, the CB1 receptor is found to be increased in the temporal lobe within the dentate gyrus compared to other cells almost as a response to the aberrant system within the cortex. The receptors are found to be increased in patients with Parkinson’s disease.
In one study, 24 patients were enrolled in a study for executive function and were registered medical marijuana users. After 3 months, 11 patients returned and using the Stroop Color Word Test, were found to have a higher level of executive function and increased speed completing tasks without being inaccurate. Patients reported less insomnia, less depression, better attention, less impulsivity and a better quality of life. There was less use of pharmacologic use and less use of opioid agents by 42% in conjunction with medical marijuana. Larger clinical randomized controlled clinical studies are needed.
Medical marijuana seems to be an excellent agent in those affected by traumatic brain injury.
Medical Marijuana as a solution for and PTSD symptom in war veterans
Cannabidiol works at the level of the 5HT1 receptor causing patients to feel less anxious and may be used in post-traumatic stress disorder. In addition, it has been found to have a role in modulating memory and instead of the learned fear response and may help with PTSD by modulating the conditioned response to a stimulus that normally begets anxiety and fearfulness. In other words, instead of the heart rate increasing or having flashbacks when a war scene is on TV, medical marijuana can exert its effect by modulating behavior by changing the learned response by not responding the same way and being calm in face of a previously anxiety-inciting war scene(4).
In summary, PTSD and traumatic brain injury are real problems faced by war veterans returning with blast injury, blunt-injury or combination type combat-related injuries. Medical marijuana may be an excellent non-intoxicating solution when cannabidiol is taken or combined with low dose tetrahydrocannabinol which can help with depression, anxiety and help modulate responses to post-traumatic stress disorder. Medical marijuana can help with executive function and attention and may be beneficial in treating war veterans suffering from mild traumatic brain injury.
- Marquardt, et al, “Symptoms of Post-traumatic stress rather than mild traumatic brain injury best account for altered emotional responses in military veterans,” J. Trauma Stress, 2018, Feb., 31 (1):114-124.
- Kontos, et al, “Residual effects of combat-related mild traumatic brain injury, “J. Neurotrauma, 2013, Apr., 15, 30 (8):680-6.
- Gruber, et al, “Splendor in the Grass? A pilot study assessing the impact of medical marijuana on executive function,” Front. Pharmacology, 2016,. Oct., 13 (7):355.
- Uhernik, et al, “Learning and memory are modulated by cannabidiol when administered during trace fear-conditioning,” Neurobiology of Learned Memory, 2018, Feb., 9, 149:58-76. doi: 10.1016/j.nlm.2018.02.009 (Epub ahead of print)