(originally published in June 2010 issue)

Dr. Melamede is an associate professor at the University of Colorado at Colorado Springs and the CEO and president of Cannabis Science Inc. He is also on the advisory board of Veterans for Medical Marijuana Access.

In order to understand why so many people -- especially our veterans, dating back to the Vietnam era -- have found marijuana beneficial for dealing with post-traumatic stress disorder (PTSD), we must first understand the endocannabinoid system (a term that refers to the cannabis-like compounds produced by the body -- literally, “cannabinoids from within”). Most animals, including all vertebrates, produce these compounds, which play an important role in combating stress.

The Free Online Dictionary defines stress as follows: “A mentally or emotionally disruptive or upsetting condition occurring in response to adverse external influences and capable of affecting physical health, usually characterized by increased heart rate, a rise in blood pressure, muscular tension, irritability, and depression.” The all-pervasive endocannabinoid system regulates each of these physiological parameters. Throughout all levels of the complexity that identifies living systems, the fundamental characteristic is one of dynamic biochemical balance (or homeostasis). Like a seesaw going up and down, opposing forces in our bodies oscillate within the boundaries defined by our genetics and life history. Thousands of peer-reviewed scientific articles have shown that our endocannabinoid system is involved in homeostatically regulating literally all of our bodily systems -- cardiovascular, digestive, endocrine, excretory, immune, nervous, muscular, skeletal and integumentary (skin).

In these biological systems, both endocannabinoids and phytocannabinoids (those found in marijuana) function in a biphasic manner. This means that these compounds can have one effect at a low dose and the exact opposite effect at a high dose. Their function is to maintain the biochemical balance in a manner similar to the way that a thermostat maintains a particular average temperature setting -- by turning the heat up when it senses cold, or turning the heat down (and turning on the air conditioning) when it gets too hot. Similarly, our bodies have inflammatory biochemical pathways that typically involve free radicals, “the friction of life,” coupled with anti-inflammatory biochemical pathways that often involve endocannabinoids, “the oil of life.”

However, evolution selected the settings for all this biochemical activity way back in our less sanitary (and far more unhealthy) past. Infectious diseases are no longer the leading cause of death in first-world countries; now, age-related illnesses are. This means that to combat infection these days, our inflammatory thermostat is set too high, while our endocannabinoid thermostat is set too low for optimal human life in a modern environment of good public health, nutrition and antibiotics.  

It should also be noted that illnesses caused by excessive endocannabinoid activity are extremely rare; one such example is found in the hypothalamus, which can drive excessive food intake, which in turn may lead to obesity and related health problems. In contrast, there are many illnesses that appear to be the result of endocannabinoid deficiencies. In fact, it may be that any illness that benefits from increased cannabinoid activity is intrinsically the result of an endocannabinoid deficiency. From this perspective, one can understand why cannabis provides such a natural solution for the treatment of so many illnesses -- especially PTSD.

PTSD occurs when an individual’s capacity to buffer stressful events is overwhelmed. The endocannabinoid system plays a fundamental role in regulating the biochemistry that appears to underlie PTSD. Cannabinoids offer protection from stress starting at birth, and are even found in mother’s milk. In the nervous system, they typically protect neurons from the cell death that results from excessive stimulation by excitotoxins (substances that have a destructive reaction with brain cells). The neurotransmitter glutamate is one such substance; it is a key player in learning and memory, but too much glutamate can lead to excitotoxicity and cell death.

Cannabinoids regulate the strength of the connections between neurons in critical areas of the brain that control the emotions, such as fear and stress, as well as memories. Repeated, coupled neuronal stimulation -- i.e., the stimulation of one neuron by another—can lead to a facilitated connection between the two, a process known as long-term potentiation (LTP). The role of endocannabinoids is to inhibit LTP (though in the right circumstances, they can also increase it).

When an organism is subject to a particularly stressful stimulus, what occurs is a combination of cell death and the establishment of memories that are too intense -- particularly unpleasant ones that are too clearly and frequently remembered.

Endocannabinoids maintain the basic neurological balance of stimulus and response by keeping neuronal activity within a safe range. We now know that a specific role of endocannabinoids is to promote the forgetting of unpleasant memories. Again we see the homeostatic balance between opposing forces (in this case, remembering and forgetting) controlled by our endocannabinoid system in a manner that inhibits illness.

One of the biological consequences that result from taking antidepressants is the development of new neurons, or neurogenesis. Interestingly, neurogenesis in the brain appears to be controlled by endocannabinoids and can specifically occur in response to excitotoxicity. Thus we see that cannabinoids have a positive influence on the factors necessary to heal those suffering from PTSD -- and even to inhibit its development in the first place.

Clearly, the scientific literature is in stark contrast to the blatant lies spread by governmental agencies. Rather than killing brain cells, cannabis actually protects them and promotes their regeneration. People suffering from PTSD -- especially military personnel injured in the service of their country -- should no longer be denied the freedom to use the natural, miraculous medicine that we call marijuana.