Marijuana and Neurotransmitters

There are many neuro transmitters in the brain, all of which control the activity of the brain in different ways. When it comes to the subject of epilepsy and seizures, it is thought that a disruption or imbalance of one or two of these neurotransmitters is the main cause of a seizure occurring. These include: gamma aminobutyric acid (GABA), dopamine, as well as serotonin. The drugs that are currently used to control epilepsy and seizures are based on controlling the activity of these neurotransmitters. Here we will cover the main functions of the neurotransmitters mentioned, along with the relationship between marijuana and neurotransmitters. Research continues to be done concerning the effectiveness of the use of cannabis used to help control seizures, but this should give you a general idea of how the process may work.


Types of Neurotransmitters

Excititory: These increases the chances that a neuron will fire

Inhibitory: These decrease the chances of a neuron firing

Modular: This type of neurotransmitter will affect both excititory and inhibitory neurons and chemical messengers.


Actions of different neurotransmitters


This neurotransmitter is inhibitory, which helps in controlling the balance between excititory and inhibitory neurotransmitters, decreasing excitability throughout the nervous system. A decrease in the activity of GABA (inhibitory) leads to an increase in dopamine activity. (excititory). GABA is actually the principal inhibitory neurotransmitter in the brain, and a decrease in this has been found in epileptic patients. Because of this, any type of drug that inhibits GABA synthesis can cause a seizure, while those that increase it is good to prevent a seizure from occurring. (3) It is also a key neurotransmitter looked at in depression, and is thought to be the most important in having a better understanding of neurobiology (1). The GABA neurotransmitter has also been thought to be involved with the level of addiction that one may have concerning the use of THC in cannabis (7). Because of the relationship between GABA and cannabis, it may play an important role in the occurrence of seizures, but more research should be done.



Serotonin is an inhibitory neurotransmitter which is involved in emotion and mood, as well as keeping a balance between different types of neurotransmitters. It is important that the levels of different neurotransmitters are balanced since an imbalance can lead to things such as depression, anxiety, seizures, and many other mental or psychological conditions. A loss of serotonin will lead to things such as depression, anger, low self-esteem, as well as mood swings. You are able to balance some of these through things such as nutrition and activity which are both important. Also, because up to 22 % of patients with epilepsy have also reported having suffered from depression (5), serotonin could play an important role for such patients. This is especially true since depression has been shown to be a possible trigger in a seizure occurring. This may mean that someone that has epilepsy but also suffers from depression, could be in what would be like a continuous cycle. In this case though, being able to control any depression or other mental condition such as anxiety would be the key to eliminating this problem.



Dopamine is important when it comes to how the brain views the risk-reward relationship. This effects one’s level of motivation which will determine the fight or flight reaction that an individual has. This means that it can have either excititory or inhibitory effects. You can see the effects in someone that has an addiction to drugs or alcohol since the levels are increased with this. Dopamine is also important because it helps with an increase in focus, allowing you to concentrate and achieve any goals you may have. A decrease can lead to things such as helplessness, anxiety, loss of connection with others, as well as a decrease in memory.



This neurotransmitter is the most abundant that can be found in the human body. It is known to most as MSG which stands for mono sodium glutamate. It is used as an additive in many processed foods, and Its main purpose is excititory, and it is released when a seizure occurs. Glutamate also assists with the balance of the GABA as well, which makes it a key to treating depression (2). Too much or too little is harmful so balance is very important. Although some glutamate is found in extracellular fluid like other neurotransmitters, glutamate is mainly intracellular living inside the cell. This makes the level of extracellular glutamate important for brain health and function.


Causes of a seizure occurring

Because of the different actions of the previous neurotransmitters discussed, whether it is excititory or inhibitory, there are numerous possible reasons for a seizure occurring. This may be because of a lack of inhibitory neurotransmitters or too many excititory neurotransmitters. The exact one’s involved may be unique to the individual since those mentioned are only some. The main one focused on for the treatment of seizures is GABA since it is inhibitory and has an effect on the level of other excititory neurotransmitters.

The use of cannabis in the treatment of seizures has increased over the past few years, but has been used for centuries to treat the condition. The exact way that it works is still being researched to be better understood. The two main parts to the cannabis plant known as cannabinoids (THC & CBD) have an effect on the neurotransmitters mentioned. This concerns the balance of inhibitory and excititory actions.


Effects of CBD 

These two parts to the cannabis plant have different effects on exititory or inhibitory neurotransmitters, so here we will look at these possible effects. It is thought that CBD has more of an effect on epilepsy and seizure frequency than THC, but both of these have some effect, it may just depend on the individual. The studies that have been done have been conclusive enough of the effects of CBD that drugs for both dravetts syndrome and lennox gastric syndrome which are chronic forms of epilepsy (4). Cannabis has been shown to have either pro or anti convulsing activity, but the place of the receptor’s whether inside or outside the cell could have a key effect since outside cannabinoids can be either pro or anti convulsing, while inward cannabinoids when activated show promising effects concerning anti convulsing properties. This may assist in decreasing seizure frequency (8) The use of CBD may also show some promising effects for other conditions such as autism as well concerning the effects of CBD on both GABA and glutamate (6), but more research needs to be done.



There are three main types of neurotransmitters, each of which serve a different purpose. These include: excititory (increase activity), inhibitory (decrease activity), and modular (either, helping control balance). There are also four main  neurotransmitters used in the brain including: dopamine (modular), GABA (inhibitory), serotonin (inhibitory) and glutamate (excititory). Having a balance in these is key to controlling epilepsy and seizures from occurring. The main neurotransmitter looked at is GABA which is inhibitory. Overall the effects of CBD on each neurotransmitter is important, but since it has been shown to effect the action of GABA depending on several factors, this will be the most looked at. Since CBD has shown to have either a positive or negative effect concerning seizures and a balance of excititory and inhibitory neurotransmitters (8), more research should be done, but since a drug with a high concentration of CBD has been approved for use, this shows promise of its effect on treating epilepsy.




1. The Gamma-Aminotyric acid B receptor in depression and reward

2. Novel pathways in the treatment of major depression

3. GABAergic mechanisms in epilepsy

4. Cannabidiol: A review of clinical efficacy and safety in epilepsy

5. Developments in depression in epilepsy: Screening, diagnosis, and treatment

6. Effects of CBDV on brain excitation and inhibition systems in adults with and without autism spectrum disorder

7. Separate and combined effects of GABA agonist

8. On-demand activation of endocannabinoid system