Several decades ago the Partnership for A Drug-Free America released a famous advertisement that any person of a certain age will be able to repeat to you verbatim. "Okay, last time..." the announcer began as a close-up of a buttered frying pan sizzled. "This is drugs," he continued, before an egg was dropped in the pan. "This is your brain on drugs. Any questions?"

As a marketing strategy it was startlingly effective. The message was clear: taking drugs will fry your brain.

Nevertheless, as some recreational drugs such as marijuana have been found to have wide-ranging medicinal properties and uses, this advertisement may be in need of an update.

In this blog post, we explore some of the emerging research on medicinal marijuana and recent findings which suggest some doses can be an effective way to treat traumatic brain injuries.

Traumatic Brain Injuries

A traumatic brain injury is an acute event that causes damage to the brain. Most TBIs fall into one of the following categories: open/closed head injury, deceleration injuries, diffuse axonal injury, chemical/toxic exposure and metabolic disorders, hypoxia, tumours, infections and strokes.

Damage from TBIs can happen in stages. A primary injury, such as a blow to the head, can cause initial trauma and tissue damage. However, secondary injuries from neurochemical reactions can often be more damaging than the initial contact. Following a blow to the head or other initial trauma, the body releases harmful neurochemical mediators that result in oxidative stress, inflammation, excitotoxicity (a process by which neurons are damaged and killed) and the death of neurons.

The Cannabinoid Defense

Researchers at Hebrew University in Israel discovered that mice with recently injured brains, while susceptible to neurochemical injury, also appeared to have a defense mechanism. These mice were found to have elevated levels of a cannabinoid compound called 2-Arachodonoyl glycerol (2-AG), which has similarities to an active ingredient in marijuana. Suspecting this compound was produced to protect the brain, the researchers administered higher doses and discovered it did help to protect the brain from this secondary damage.

Other research has similarly found that the two major cannabinoids in marijuana – tetrahydrocannabinol (THC) and cannabidiol (CBD) – have an effect on the CB1 and CB2 receptors of the brain's endocannibinoid system. This reaction prevents proinflammatory cytokines from being released following brain trauma. One study has also linked a positive THC screen with significantly reduced mortality following TBI.

Time To Light One Up?

If marijuana has such helpful properties, is it time to light one up in the name of good health? Not exactly. The researchers from Hebrew University noted that dosage is extremely important to benefit from cannabinoids following a TBI and the varying potency of marijuana strains would make non-medicinal grade product unreliable.

There are other reasons people may use marijuana following a TBI. For example, a number of former football players experiencing the effects of chronic traumatic encephalopathy (CTE) – repeated TBIs – have reported using the drug successfully to treat chronic pain associated with the condition instead of opioids.

Nevertheless, experts caution about the inherent dangers of self-medicating with marijuana following a TBI. In an article for, Dr. John Corrigan explains that improperly using drugs after sustaining a brain injury can delay recovery; cause difficulty with concentration, memory, or balance; and increase the chance of seizure or additional brain injury.

Hope For Future Treatment

Currently there is no effective drug treatment for TBI. If clinical trials confirm the Hebrew University findings and pave the way for safe, measured use of cannabinoids in humans, that may change.

The old idea that taking drugs will fry your brain probably needs some refinement in light of the encouraging studies on medicinal marijuana's many uses. However, the complexity of the brain and the many unknowns in brain science make caution key when contemplating any untested treatment.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.