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Marijuana Use And Memory Loss

Isaac Alexis, M.D., AAMA, AMP-BC

Medically reviewed by

Isaac Alexis, M.D., AAMA, AMP-BC

January 17, 2019

The cannabinoid system in the body responds quickly to exposure to THC, impairing a person’s memory, sense of time, and perception. Long-term exposure or use of marijuana has been shown to slow blood flow to the brain, and by similar mechanisms, reduce neural activity, the latter of which impacts memory recall.

There are multiple studies that examine memory loss, or cognitive dysfunction relating to the use of marijuana. Today’s levels of delta-9 THC are higher than ever before, and concentrated or distilled forms of the compound are now being sold on the streets. In other words, this ain’t your papa’s pot. The amount of THC found in the average joint is triple the levels of Woodstock-era THC. And the higher the levels of THC being ingested, the greater the effects, and potential for long-term psychosis.

What The Research Tells Us About Marijuana Use And Memory Loss

Marijuana doesn’t just affect memory loss by one simple mechanism; it slows everything from encoding of memories, to the retrieval of those memories with long-term use. Research suggests THC’s effect on an individual varies with the age of exposure and predisposition to addiction and mental disorders, including schizophrenia.

Tests on subject groups in one study, indicated lasting cognitive impairments of varying severity between regular users over a three year period, and those who did not use marijuana, even following a two year period of abstinence for the user group. On average, of otherwise healthy test subjects (no co-occurring mental disorders and no other drug use), who had previously tested on par with their peers on cognitive tests, saw a nearly 20 percent drop in test scores following regular marijuana use.

One of the most evident pathways for this decline comes from THC’s effect on cells in the brain that provide support for neurons in the brain. When these neurons are reduced or impacted, the brain’s ability to store memories is impaired.

Additionally, the pathway between short-term and long-term memory formation is regulated by a part of the brain known as the hippocampus. Damage to this part of the brain results in the brain’s inability to form new memories. Delta-9 THC, the same compound that generates the high people seek when using marijuana, is toxic to hippocampal cells. Established memories will not be affected, but memory formation can be significantly impaired.

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Isn’t Medical Marijuana Safe And Effective?

Medical marijuana is effective in relieving symptoms like nausea, pain, and may sometimes be used to reduce anxiety, but this does not negate it’s effects on memory. This is an issue of particular concern to those patients in the early stages of dementia. Researchers are currently looking at ways to block the ill-effects of THC on memory, however, there is a long way to go in both the regulation of this drug and understanding the interactions of THC along with the many other psychoactive compounds found in marijuana.

Marijuana-Induced Memory Loss Impacts Productivity

Memory loss from repeated exposures to the THC found in marijuana can lead to a host of other related symptoms, including reduced overall productivity. Memory loss can also create feelings of anxiety and depression when a person is acutely aware they are not functioning to their full potential. This may be accentuated in individuals who were suffering with a co-occurring mental disorder that fueled use of the drug in the first place.

Marijuana-induced memory loss can contribute to:

  • Decrease in productivity
  • Inability to hold down a job
  • Trouble in relationships
  • Depression
  • Anxiety

Moreover, regular use of marijuana can lead to the use of other drugs and may put someone at a higher risk of addiction.

Reversing Memory Loss After Long-term Marijuana Use

While some of the long-term effects of marijuana may be irreversible, there are ways to improve memory. Exercise, a healthy diet, and brain puzzles or new activities stimulate new connections within the brain. Exercise improves dopamine production in addition to improving neural pathways. This can result in a reduction of anxiety or depression, and even reduce drug cravings.

Foods high in essential fatty acids are also an important part of improving brain health and memory. Omega-3 fats are especially good for stimulating new neural growth within the brain. Many seeds, nuts, leafy greens and certain oils contain omega-3 fatty acids.

Another way to improve overall cognitive functioning following long-term use of marijuana is to engage in learning a new activity. Start with activities that involve some physical component, like dancing, and then move up to working on brain puzzles or games that stimulate and challenge the brain, such as chess. These activities stimulate parts of the brain essential to memory retention and recall.

While left implied, if you are suffering from memory loss regardless of the cause, use of marijuana can further inhibit cognitive functioning. It is best to stop using marijuana and begin working on the positive actions that will lead to a healthy brain and body.

Reclaim Your Brain; Get Help For Your Marijuana Addiction Today

If you have been using marijuana for some time and feel like you need the drug to function, it may be time to seek professional help. Physical and strong psychological addictions can form and may require a comprehensive recovery plan to stop the cycle of addiction and its ill-effects on memory and your overall health. is your online resource for the evidence-based care and support needed to take you from a place of using to a place of recovery. Contact us to speak with someone in confidence and discover a new and rewarding path forward beginning today.

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