How Does Marijuana Affect The Brain?

As recreational Marijuana use becomes legalized throughout the US, many people now wonder how Marijuana affects the brain and whether or not it kills brain cells. Just as years of heavy alcohol, Meth, and Heroin use can cause some irreversible brain damage, prolonged Marijuana abuse can affect the ability of brain cells to convey messages (also known as brain activity). Using Marijuana can cause damage to brain cells that results in a number of concurrent symptoms throughout the body.

Like other drugs, components of Marijuana bind with specific receptors in the brain. Tetrahydrocannabinol (THC) is Marijuana’s primary Psychoactive ingredient, and it attaches to the brain’s Cannabinoid receptors (officially known as Cannabinoid receptor type 1 or CB1). These receptors connect to nerves in the brain which govern memory, appetite, pain regulation, and mood.

When a person smokes Marijuana, they may notice they struggle with staying focused or recalling important details. This can worsen with prolonged Marijuana use, resulting in problems like poor memory and concentration. Motor skills can also be affected by the drug. If users decide to drive while high, they can endanger their lives and the lives of others.

At this time, scientists are not fully aware of the long-term effects of Marijuana use on the brain. They have, however, found a correlation between the use of Marijuana during brain development and decreased IQ later in life. Therefore, exposure to THC as a child may cause changes in cognition and memory that can last for decades. Less research has been done on adults who begin using Marijuana after the adolescent stage, however recent research has found a negative relationship between THC and higher levels of thinking including the cognitive ability to remember important information, plan, organize and solve problems, and regulate emotions/behaviors. Whether or not those effects are reversible, scientists are not certain.

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Effect Of Marijuana Use On IQ

The effect Marijuana has on the brain is influenced by the amount a person has smoked and the user’s age. Individuals under 25, whose brains are still developing, are most susceptible to the effects of Marijuana on the brain. A study of Marijuana’s effect on IQ revealed individuals who began using Marijuana at a young age lost 6 to 8 points from their IQ by middle age. Moreover, those who smoked Marijuana throughout their adolescence, then stopped, did not regain their IQ points. Conversely, individuals who began using Marijuana in their adulthood did not experience any IQ loss.

Synthetic Marijuana’s Effect On The Brain

Synthetic Marijuana, a man-made Hallucinogenic substance typically sprayed onto plant material, is not safe for human consumption but has become popular in recent years. Also known as “Fake Weed,” it produces mind-altering effects and can cause the individual to act in an odd manner. Synthetic Marijuana is illegal and may have toxic ingredients that can cause increased heart rate, unexplained bleeding, and vomiting.

Similarly to Marijuana, Synthetic Marijuana affects the brain by attaching itself to the Cannabinoid receptor type 1 (CB1) found in both the central and peripheral nervous systems. Synthetic Weed binds more strongly to CB1 receptors than THC, making it at least 100 times more potent in the brain. Because CB1 receptors have multiple locations in the brain, side effects can be intense and harmful.

Synthetic Marijuana may cause the brain and body to experience:

  • Memory loss
  • Seizures
  • Psychosis
  • Cardiac and respiratory problems
  • Stroke
  • Paranoia
  • Hallucinations
  • Altered perception or euphoria
  • Violent behavior
  • Kidney and brain damage

In addition to the above symptoms, Synthetic Marijuana can be addictive to individuals who take it. After prolonged use of Synthetic Marijuana, brain cell activity is likely to decline with a concurrent increase in negative physiological symptoms like the ones above.

Short And Long-Term Effects Of Marijuana Use On The Brain

The immediate, short-term effects of Marijuana use on the brain include:

  • Difficulty judging distances
  • Difficulty remembering
  • Fatigue
  • Confusion
  • Paranoia
  • Anxiety

Long-term effects include but are not limited to:

  • Some cognitive impairment
  • Some memory loss
  • Increased Marijuana tolerance
  • Marijuana dependence
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Marijuana can have calming effects on the individual, but when overused or combined with other substances can be very harmful. Stopping Marijuana use can be difficult; if you or a loved one struggles to stop or endangers their life, detox and treatment may be required. Treatment takes individuals away from triggers that cause relapse. Meanwhile, counseling can help patients in recovery learn and understand what they need most.

Medications can help reduce cravings for Marijuana, and detox eliminates toxins in the body and returns it to its healthy state. Rehab-related help is available. No one needs to struggle with addiction alone. Contact a treatment provider today.

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Last Edited:


Krystina Murray

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  • Krystina Murray has received a B.A. in English at Georgia State University, has over 5 years of professional writing and editing experience, and over 15 years of overall writing experience. She enjoys traveling, fitness, crafting, and spreading awareness of addiction recovery to help people transform their lives.

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Theresa Parisi

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