Most adult-onset cannabis consumers use it safely. But many adolescent-onset users and some adult-onset users do experience harm, or even dependence, and would benefit from knowing four basic facts about cannabis. Knowing these facts can help people recognize the significant early warning signs of excessive use.

1. The Human Brain Is Hardwired for Pot

Our brains contain complex chemistry. Nerve cells communicate with each other using chemical transmitters such as serotonin, dopamine, GABA, etc. One chemical system, the ECS, is uniquely positioned to regulate all the other neurotransmitter systems. Good mental and emotional health requires a healthy well-balanced ECS. The best known ECS transmitter is anandamide, though several others exist with more technical names such as 2-AG. Neuroreceptors for ECS transmitters are the most common receptor in the brain and are densely concentrated in different areas. Scientists first discovered anandamide receptors by using a very powerful modification of the THC molecule. For this reason, anandamide receptors came to be called “cannabinoid” receptors (CBR, for short) and the ECS came to be called our endogenous cannabinoid system, or endocannabinoid system (ECS for short). The important thing to understand is that the anandamide system has nothing inherently to do with cannabis, and yet they sit there ready to accept THC stimulation. When ECS receptors are blocked and ECS activity is reduced, people become depressed or even suicidal. A healthy well-balanced ECS is necessary for good mental and emotional health.

2. THC Resembles Anandamide and 2-AG

While THC is naturally found in the cannabis plant, it is not naturally found in the brain. THC has most of its effect only because the brain’s ECS receptors interact with it in a way that activates the ECS far stronger, and far longer, than anandamide and 2-AG’s activation. THC activates the entire ECS beyond its normal physiological limits. Most people find this rather pleasant, and it is the basis for many of the medical benefits of cannabis. Nevertheless, this unnaturally high level of ECS activity stimulated by THC has a temporary price as the brain begins adjusting to achieve homeostatic stability.

3. When Used Too Frequently, THC Reduces the Number of ECS Receptors

The ECS responds to the unnaturally high activation stimulated by THC by gradually reducing the number of its receptors. By “downregulating” its anandamide receptors, THC has fewer places to activate the ECS, thus bringing the entire system back closer to normal. Continued THC stimulation reduces anandamide receptors by 20-60%, depending on the part of the brain being measured. With total abstinence from THC, this reduction in anandamide receptors lasts for four to six weeks and is associated with a range of measurable cognitive and emotional changes. Once an ECS with reduced anandamide receptors is no longer stimulated by THC, anandamide and 2-AG alone do not produce normal levels of ECS activation. The state of downregulated receptors and lower than normal ECS activity include measurable amounts of the following:

• Learning and memory decrements
• Executive function decrements such as
  • Higher order cognitive abilities, including abstraction
  • Slower processing speed
  • Decreased ability to assess risk
  • Decreased awareness of errors

• Increased impulsivity
• Decreased sensitivity to subtle emotional cues
• Increased psychotic disorders, including schizophrenia

4. Cannabis Dependence Is Real

While people like to argue about the difference between dependence/addiction and mere habit, scientists define dependence by several objective realities. All drugs of addiction cause an unnaturally high level of dopamine in the reward center. THC causes an outpouring of dopamine in the reward center. All addictive drugs cause a predictable set and course of withdrawal symptoms. When regular THC users abstain, they often experience physical restlessness, anxiety/irritability, boredom, decreased appetite, and insomnia, with this last withdrawal symptom lasting up to six weeks. Withdrawal from addictive drugs can be aborted by restarting the drug, and restarting THC quickly reverses the symptoms of withdrawal listed above.

The prevalence of THC dependence is clouded by some technical changes in how it has been measured. I will explore these details in my next post. In brief, around 9-13% of adult-onset cannabis users will experience dependence at some point during their lifetime. The prevalence of addiction for adolescent-onset cannabis users is far higher.

Note: Multiple references for all the above facts are available and collected in my book From Bud to Brain.

Guidelines for Using Cannabis Safely

There is no “one size fits all” guideline for how much cannabis is safe. Every brain has its own unique DNA, and every individual has her or his own unique experiences and personality. Using once a week can be safe for some, while it is too frequent for others. The guiding principle for everyone should be awareness of the five signs of using too frequently. When you do not use cannabis, do you begin experiencing any of the following?

• Physical restlessness
• Anxiety or hostility
• Boredom or depression
• Decreased appetite
• Insomnia

If you see any of these five signs, be honest with yourself. You may have used cannabis frequently enough to reduce the number of anandamide receptors in your brain. They will grow back if you abstain from cannabis for a while. Greater mental acuity and emotional clarity may also return. Remember, good mental and emotional health require a healthy and well-balanced ECS.