How Cannabis Affects Your Brain

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Categories : Medical cannabis

How Cannabis Affects Your Brain

Cannabis contains over 80 cannabinoids that act on the human brain and body in various ways. Take a look at how CBD and THC influence your brain.



The endocannabinoid system (ECS) is found in the brain, central nervous system, and peripheral nervous system. There are also numerous cannabinoid receptors in the gut and smooth muscles. The ECS plays a vital role in homeostasis, maintaining healthy internal functions of the human body. It actively regulates mood and memory, physiology and pain sensation, appetite, and overall health.

There are two primary cannabinoid receptors: CB1 and CB2.

CB1: These receptors are found predominantly in the brain and central nervous system. They also exist in other organs and connective tissues. The phytocannabinoid (phyto—from plants) THC and the endocannabinoid (endo—from within) anandamide bind to this receptor. The activation of the CB1 receptor by anandamide produces feelings of bliss. The activation of the same receptor by THC produces the high associated with cannabis.

CB2: These receptors are found predominantly in the immune system and surrounding structures of humans and other mammals. They are responsible for modulating immune responses, and their stimulation catalyses the anti-inflammatory effects of cannabis. Inflammation is proving to be a significant symptom and cause of many diseases. Activation of the CB2 receptor is an immune response by the body. Stimulation of CB2 receptors in the brain has been shown to have anxiolytic effects. It has also been observed to help regulate sleep and decrease the effects of environmental stress.


High, stoned, ripped, lifted, bent, clubbed, and buzzed are some of the many terms used to describe the effects of cannabis. It is quite commonly known that the more THC a plant has, the stronger the effects. This psychoactive cannabinoid also interacts with a number of other non-psychoactive cannabinoids to produce “entourage effects”.

But just what is happening in your brain when you get high?

Before delving into the biology of the matter, what are the effects of cannabis? Most common is euphoria, which is a feeling of intense excitement and happiness. Diminished stress and anxiety, altered time perception and spatial awareness are also common. Amplified sociability, increased talkativeness, enhanced creativity and focus, and sometimes paranoia are experienced as well. Depending on the strain and the brain, each of these characteristics can manifest with different intensities.


The endocannabinoid system is a relatively new discovery. The endocannabinoid anandamide was only identified in the nineties. It is a fatty acid neurotransmitter whose name is derived for the Sanskrit word for joy, bliss, and delight. It has even been called the “bliss molecule”.

The most common misconception prior to the discovery of anandamide was that the cannabis high was caused by a flood of dopamine into the brain. Dopamine is the feel-good reward compound released by the brain that affects the prefrontal cortex and basal ganglia. This is true of many other substances—cocaine and amphetamines, for example. However, with regard to cannabis, contemporary studies are proving this long-held assumption incorrect.

Anandamide and THC both bond to the CB1 and CB2 cannabinoid receptors. Most importantly, it is the binding to the CB1 receptor that induces feelings of happiness. However, anandamide breaks down quickly, so the feelings of joy diminish rapidly. THC binds to the same receptor, yet it is metabolised more slowly, producing a lasting feeling of happiness.

When you ingest cannabis by smoking, vaping, or eating, the THC binds to receptors in the neurons like a key into a lock, telling the body to do something. The goal in this case is to create a sense of bliss. Similar effects can be caused by chocolate, yoga, or running (runner’s high).


Just to muddy the waters a bit, THC has a biphasic effect. When consumed in just the right amounts, feelings of happiness predominate. When there is overindulgence, the opposite effects can happen. This is where anxiety, paranoia, and discomfort emerge. In general, most people experience a sense of happiness when they consume cannabis. Yet, one out of five people will experience the complete opposite.

The naturally occurring enzyme FAAH acts to deactivate anandamide. Some individuals are genetically predisposed to producing less FAAH. In these people, anandamide breaks down more slowly, so they are generally more relaxed. In these individuals, consumption of cannabis can have a paradoxical effect. Instead of experiencing happiness, they experience anxiety or distress, and are less likely to consume cannabis recreationally.

How Cannabis Affects Your Brain


THC and CBD (cannabidiol) are two of over 80 cannabinoids found in cannabis. So far, they are the best understood and both have been shown to have therapeutic value.


Using low to moderate doses of THC has been observed to have a number of effects, apart from the euphoria sought out by the recreational user. Noted beneficial actions include:

• Mood elevation and relaxation
• Treatment of insomnia
• Blocking perception of pain
• Nausea reduction
• Appetite stimulation

The biphasic effect of THC means it has an effective therapeutic window of low to moderate doses. Higher doses can have the opposite effect to those desired. For example, in the treatment of chronic pain, most research suggests that moderate doses ease pain while larger doses exacerbate perception of pain. It is always best practice to follow a physician's instructions with complementary marijuana treatments.


CBD is the non-psychoactive cousin of THC; in fact, CBD moderates the effects of THC. Cannabidiol is proving to have the most promising therapeutic value of the cannabinoids discovered thus far. It acts in a number of ways and is proving to be beneficial in addressing a number of problems affecting humans.

• It acts on the hippocampus region of the brain, stimulating neurogenesis (manufacture of new neurons), improving memory and anxiety management.

• There is evidence to suggest that CBD disrupts opioid receptors. This makes cannabis a possible treatment for opiate addiction by rewiring the brain’s reward system.

• CBD inhibits the reuptake and metabolism of anandamide, increasing the body’s natural endocannabinoid levels. This effect extends feelings of well-being.

• Studies suggest CBD can act as an anti-epileptic, sustaining positive effects on other spasmodic conditions like multiple sclerosis.

• CBD binds to the TVR1 receptor, which helps regulate body temperature, inflammation, and pain tolerance. Using CBD in the treatment of chronic pain is of particular interest to researchers.

• In a 2011 study where CBD was tested against placebos, it was observed to have anti-anxiety effects.

• CBD acts as a neuroprotectant and may be effective in the prevention of neurodegenerative diseases.

Research continues into the efficiency of CBD treatment for a number of conditions, including schizophrenia and other psychotic disorders, type 2 diabetes, inflammatory bowel disease, and some types of tumours.

The exciting world of cannabis as a medicine is opening up as the stranglehold of prohibition is releasing. More in-depth studies on the function of the endocannabinoid system and how cannabis affects it are needed. The body and brain are tremendously complex organic machines, on which marijuana acts in a number of beneficial ways. Perhaps as these actions become more and more understood, cannabis will become destigmatised the world over.