Effects of CBD and its related compounds (THC, cannabis, hemp) on the brain
The effects of cannabis and all its related substances on the brain have been proven by recent research. Both the harmful and beneficial effects of cannabis and their variations with age and disease have been updated by the researchers.
In the annual meeting of the Society for Neuroscience, held in San Diego CA, in 2018, all the findings related to cannabis, CBD, THC, and hemp were presented.
This research revealed the different effects of marijuana (cannabis) on the developing brain as well as the adult brain and how it produces its effects.
This class of drugs i.e. cannabis, CBD, THC, and hemp have several different modes of action and depending on their mode of action, resultant effects are produced in the brain. For example, some of these acts by interfering with thought and memory while others act by disrupting the link between different parts of the brain as well as between the brain and other parts of the body. There is one common thing between their mode of action that is they all act by affecting some chemical messengers and metabolic compounds.
To know the effect of all these compounds on the brain, we need to go into some detail. Let’s look at these compounds one by one and the effects they produce by modifying brain functions.
Cannabidiol known as CBD
CBD is the second most important compound that is obtained from the cannabis plant, the first being the THC. The advantage that CBD has over THC is that it is not psychoactive and also does not produce the so-called "high" effect. But if you are taking CBD with THC, it will interfere with the effects produced by THC. It may potentiate some of the effects of THC while inhibiting others. That's not all, CBD has some of its effects that it can produce without combining with THC or other cannabis compounds.
To understand the effects of CBD on other parts of the body, we must first learn how our brain processes it and in what ways it modifies brain functioning.
Effect of CBD on the Brain
Despite all the current advancements in science and technology and all the research conducted uphill now, we still know very little about the functioning of the human brain. So the study relating to the effects of CBD on the brain is limited to animal research.
Some experimental trials are being performed on the human brain as well and they are proving to be very successful. The breakthrough was made in the 1960s, a team of Israeli scientists led by Dr. Raphael Mechoulam made a breakthrough in this regard. The identified the chemical structures of CBD and THC. Continuing their work, the endocannabinoid system of the human body was discovered. It is the system by which cannabinoids like CBD interact with the human brain and body. Evolutionary evidence suggests that humans must have evolved this system with time to process the cannabinoids in their brain and body.
The endocannabinoid system
This system includes receptors present throughout the human body that process cannabinoids. All these receptors are linked to the brain via our nervous system. Simply we can say that different chemicals react with different receptors to produce different effects. There are two kinds of receptors in the endocannabinoid system, CB1 and CB2 receptors that are present throughout the body especially in the brain. These receptors detect the natural cannabinoids produced by our body. CBD modifies the response of these natural cannabinoids on the receptors and produces the following effects.
- Reduces neuroinflammation
- Promotes the development of healthy brain cells
- Protects against oxidative damage
- Increase the level of neurotransmitters, serotonin, and glutamate, that is important in the treatment of depression.
- Acts as an anticonvulsant to prevent and treat epileptic seizures.
Tetrahydrocannabinol, known as THC
The psychological effects of cannabis are produced by THC. According to the National Institute on Drug Abuse (NIDA), how THC acts on the body is the same as for natural cannabinoids.
THC is obtained from the resin secreted by glands of the marijuana plant. These resin secreting glands are abundant around the reproductive organs of the plant. Along with THC, several other compounds are present in this resin. These compounds are collectively named as cannabinoids. CBD is one of these cannabinoids.
Effects of THC on the Brain
THC produces its effects by attaching to the same cannabinoid receptors CB1 and CB2. In the human brain, these receptors are concentrated in those parts that are associated with memory, thinking, coordination, time perception, and pleasure.
According to NIDA. THC activates these receptors and affects thinking, memory, movements, pleasure, coordination and time perception and produces the following effects.
- THC stimulates cells in the brain to release dopamine, creating euphoria.
- It interferes with how information is processed in the hippocampus thus affecting memory.
- THC can induce hallucinations, change thinking and cause delusions. On average, the effects last about two hours and kick in 10 to 30 minutes after ingestion.
- In overdose, it may produce anxiety, elation, tachycardia, sedation, pain relief, and short-term memory recall issues.
The initial effects caused by the THC subside after an hour or two, but the THC stays in your body for a much longer duration. The terminal half-life of THC ranges from 20 hours to 10 days, depending on the amount and potency used. It means that if you take 1 milligram of THC having a half-life of 20 hours, you will still have 0.031 milligrams of THC in your body for more than four days.
Effect of Cannabis on the developing human brain
Cannabis is still the product of choice for many illicit drug users in Australia. According to a survey, the number of people using cannabis is fivefold as compared to those using cocaine or methamphetamines.
But the long-term effects of cannabis on memory, cognition, and brain health are still debatable. There is some growing concern about the effect of THC on the brain development of its users who are mostly teenagers.
Let’s take a look at what the latest research says about the long-term effects of cannabis on the human brain and how these effects can be reversed.
- Recent research has shown that teenagers with high cannabis use earn a lower wage, have a lower level of educational attainment and IQ, and are more likely to engage in hard drug abuse or heavy alcohol consumption.
- Heavy cannabis use that is defined as daily use for at least one year, is consistently associated with poorer attention and memory, as well as earlier and increased rates of mental health problems.
- Researchers have also identified differences in the brain associated with these cognitive and mental health impairments.
Some other factors can influence how cannabis affects the developing brain. These factors include the use of other substances, age, and rate of exercise, family history, education level, childhood abuse and neglect, the composition of cannabis as well as already present neurological impairments.
Considering all these factors is not possible while researching cannabis. Only two or three factors are studied at a time. So the research can’t accurately describe the effects that cannabis will produce on the mental health and brain structure of a normal person.
Are The Impairments caused by cannabis are permanent?
The capacity of the human brain to adapt to changes in the environment and the stress exerted on it is called brain plasticity. In simple terms, it means that constant changes are occurring in the brain to optimize its functioning. These changes can optimize brain functioning even when it is damaged or injured.
For example, brain hemorrhage can damage certain areas of the brain but due to brain plasticity, some functioning of that region may be retrieved. This occurs by rewiring of neural connections between the leftover regions in an attempt to adapt to the damage that occurred as a result of the hemorrhage.
Brain plasticity helps in the recovery of damage caused by cannabis in a very similar way. Although there is very little research in this regard, it still proves that brain plasticity is the main factor in recovering from damage caused by cannabis.
Research related to the effects of cannabis on the brain
- Some of the well-known studies have proved that the changes caused by cannabis are mostly irreversible except that some degree of recovery is possible in some cases.
- One large-scale research conducted for eight years showed that memory impairments result from heavy cannabis use. But the individuals recovered over time as soon as they stopped using cannabis.
- Some Other studies have shown that as little as three to six weeks of abstinence is sufficient for improvement in the memory.
- The “high” caused by cannabis is due to the psychoactive substance THC.
- A large scale study carried for over forty years showed that the brain's ability to recover from the damage caused by cannabis is limited. This study showed that even if cognition is improved by some period of abstinence, cognitive impairments persist for the whole life.
Uphill now, there is no proven research that shows that the persistent effects of cannabis on the brain can be improved with abstinence.
Occluding all the research we can say that the recovery of the brain from the permanent damage is somewhat slow and in some cases, it may take a lifetime to recover. It still requires a lot more research to provide some substantial evidence.
Short-term consumption is beneficial for the brain
Several pieces of research have proved that CBD, THC, and cannabis can have medicinal benefits in the treatment of pain, anxiety, depression and PTSD (post-traumatic stress disorder) when used for a shorter duration of time. New research has also shown that CBD has neuroprotective effects as well.
Long-term THC could affect user’s brains
Dr. Sodhi, a well-known researcher says that “ [Long-term cannabis use is] suspected to cause memory problems, lack of motivation, tolerance, contribute to worsen paranoia, and certain psych disorders such as schizophrenia,” he further says, “there simply aren’t enough studies that offer a definitive answer on whether or not long-term cannabis use affects the brain, and how.”
Getting high Dose of CBD, THC or Cannabis doesn’t kill brain cells
Although frequent, heavy use of cannabis causes addiction as well as a dependency on some users and the symptoms mentioned above, yet there is good news. Cannabis and its related compounds like CBD, THC, and hemp cannot kill brain cells in adult users.
THC can indeed get you "high" but that doesn't mean that it kills brain cells. Getting high is a different phenomenon that doesn't involve killing brain cells. The so-called "high” is an altered state of mind produced by THC that is a mild hallucinogen. None of the cannabis compounds kill the brain cells.
The higher the dose, the higher will be the “high” produced by the compound. For example, the more cannabis smoke you inhale and the longer you hold it in your lungs the more intense “high” it will produce. But this for sure doesn’t cause neurotoxicity in the brain. It just makes you higher.
However, the effect of cannabis on the brain cells of children and teenagers is different. The spongy organ called the brain inside of children and teens is yet to fully develop.
Long term cannabis users that have been using it since teenage life are shown to have lost an average of eight IQ points between the ages of 13 and 38. The more disturbing effect is that even after the abstinence from cannabis and related compounds the damage that occurred as teenagers doesn't revive.
Other Physiological Effects of cannabis and related substances
Cannabis and its related compounds don't affect the brain only. They affect all the parts of the body either directly or by influencing the brain. Given below are some of the effects:
- Problems with memory and learning
- Distorted perception
- Difficulty with thinking and problem solving
- Loss of coordination
- Increased heart rate
- Anxiety, paranoia and panic attacks
- In addition to these effects, cannabis smokers are prone to the same lung problems as tobacco smokers, such as bronchial asthma, bronchitis, and emphysema.
- Other effects include dry mouth, red eyes, impaired motor skills, and impaired concentration.
- Long-term use of the drug can increase the risk of damaging the lungs and reproductive system,
Although there are a lot of negative effects of cannabis on the human body, some recent research has proved the medicinal uses of cannabis as well. Some of the health benefits include
- Nausea suppression
- Appetite stimulation
- Stop convulsions
- Eliminate menstrual pain
- Relieve eye pressure
Because of all these effects and many more, cannabis is being used in the treatment of several conditions:
- Cancer and AIDS (to suppress nausea and stimulate appetite)
- Glaucoma (to alleviate eye pressure)
- Epilepsy (to stop convulsions)
- Multiple sclerosis (to decrease muscle spasms)
Still, some of the researchers believe that the negative effects of cannabis and its related compounds like CBD, THC, and hemp surpass their positive effects. Cannabis has been listed as Schedule I substance by the U.S. Drug Enforcement Agency. Schedule 1 is reserved for "the most dangerous drugs and includes substances with severe psychological or physical dependence such as heroin, Ecstasy, and LSD.