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How does CBD affect the brain?

What Are CBD’s Effects On The Brain?

One of the most common reasons that CBD users give for taking CBD oil is to reduce anxiety. Another common reason is to improve mood and reduce depression. But, quite often, you’ll read that CBD, unlike THC, is not a psychoactive cannabinoid. It can be a little confusing.  Does CBD have an effect on the brain or doesn’t it? In other words, what are CBD’s effects on the human brain?

Two CBD Misconceptions

The fact of the matter is that CBD is psychoactive. It does, indeed, interact with neuron receptors in the brain causing changes to the way the brain functions, which means it is psychoactive. However, it does not change a users perception of reality, nor does it cause a high In other words, it’s non-intoxicating. Another word for this is non-psychotropic, which means relating to or denoting drugs that affect a person's mental state.

Another common misconception is that CBD interacts directly with endocannabinoid receptors. This, again, is not the case. There are two types of endocannabinoid receptors—CB-1 found mainly in the brain and central nervous system, and CB-2 found mainly in the immune system and major organs.

As it turns out, CBD does not interact directly with either of these two types of receptors. It does, however, mimic other types of signaling molecules and thereby interacts directly with other kinds of receptors, some of which are found in the brain. It also has interesting effects on the endocannabinoid system (ECS). It can increase levels of certain endocannabinoids (those produced naturally by the human body), and it can block the uptake of certain cannabinoids, of which THC is the most interesting example.

CBD Reduces The Effects of THC. But How?

CBD has been shown in a number of studies to reduce the effects of THC.

In this 2013 report entitled, “Cannabidiol interferes with the effects of Δ9-tetrahydrocannabinol in man,” the authors of the study wrote:

Based on previous observations that cannabidiol (CBD) blocks some effects of Δ9-tetrahydrocannabinol (Δ9-THC) in laboratory animals, the present work was carried out to study possible interaction between CBD and Δ9-THC in human beings. In a double-blind procedure, 40 healthy male volunteers were assigned to 1 of 8 experimental groups, receiving peroral route, placebo, 30 mg Δ9-THC, 15 30 or 60 mg of CBD, and mixtures of 30 mg of Δ9-THC plus either 15, 30 or 60 mg of CBD respectively. Pulse rate, time production tasks and psychological logical reactions were measured at several time intervals after drug ingestion. 30 mg Δ9-THC alone increased pulse rate, disturbed time tasks and induced strong psychological reactions in the subjects. 15–60 mg of CBD alone provoked no effects. On the other hand, CBD was efficient in blocking most of the effects of Δ9-THC when both drugs were given together. CBD also decreased the anxiety component of Δ9-THC effects, in such a way that the subjects reported more pleasurable effects.

Researchers suspect that CBD reduces the CB-1 receptors’ affinity for THC. Put another way, CBD blocks the reception of THC by decreasing its ability to stimulate CB-1 receptors.

In addition to its indirect influence on the CB1 and CB2 receptors, CBD can increase levels of the body’s own naturally-produced cannabinoids (known as endocannabinoids) by inhibiting the enzymes that break them down. Some of these endocannabinoids likely play a role in CBD’s overall effects.

CBD’s Effects On Other Types of Receptors In the Brain (Non ECS)

The neurons which make up the human brain connect to each other via structures called synapses. One neuron communicates with another by releasing signalling chemicals known as neurotransmitters which are passed along via the synapses.

There a variety of types of receptors with corresponding neurotransmitters, each with its own particular set of functions. Some of these include opioid receptors, serotonin receptors, and dopamine receptors. Cannabinoids such as THC or CBD can mimic naturally produced neurotransmitters such as dopamine and anandamide (which is associated with serotonin levels) and have pronounced effects on the brain via these non-ECS receptors.

Let’s take a closer look at these specialized receptors.

Opioid Receptors

Opioid receptors play a role in pain regulation. These receptors are the key targets of potentially deadly pharmaceuticals such as morphine, heroin, and fentanyl. The interaction of CBD with opioid receptors may be partly responsible for CBD’s reported pain reducing properties. CBD also has anti-inflammatory properties which can help to reduce pain.

Dopamine Receptors

Dopamine receptors play a crucial role in regulating aspects of behavior by rewarding behaviors upon which survival depends, such as eating and sex. Dopamine can result in improved mood. These receptors can play a role in mood disorders and addictive behaviors.

Serotonin Receptors

CBD has been shown to directly activate a number of different kinds of serotonin receptors in neurons. Serotonin seems to play a vital role in reducing anxiety and turning off fear responses. CBD’s influence on serotonin levels is thought to be responsible for its anxiety-reducing properties and is also thought to reduce cravings and addictive behaviors.

Professor Roger Pertwee, a pharmacologist from the University of Aberdeen, spoke to Leafly about CBD’s ability to act on these non-ECS receptors.

“[CBD’s] apparent ability to enhance the activation of serotonin 1A receptors supports the possibility that it could be used to ameliorate disorders that include: opioid dependence, neuropathic pain, depression and anxiety disorders, nausea and vomiting (e.g. from chemotherapy), and negative symptoms of schizophrenia.”

Below is a chart based on Leafly’s report on this topic. It shows four types of receptors, their type of interaction, and their effects on the brain.  

Brain receptors affected by CBD.
Brain receptors affected by CBD.


Because of the wide variety of receptors with which CBD interacts, it’s going to take some time and a good deal of research to completely understand the full effect that cannabinoids such as CBD and THC have on the brain and to determine their therapeutic benefits.