Medically Reviewed

Marijuana Side Effects: Physical, Mental, and Long-Term Effects

3 min read · 5 sections
Evidence-Based Care
Expert Staff

With varying degrees of decriminalization and legalization of non-medical marijuana (cannabis) use throughout the country as well as a decline in the perception of the harms of such use, marijuana use has grown.1 However, despite its prevalent use and the relatively favorable public perception regarding the safety of such use, marijuana is not without risks.

Read on to better understand marijuana, its short- and long-term effects on your physical and mental health, and how to get help if you or someone you love misuse it.

Take Our Marijuana Addiction Self-Assessment

Take our free, 5-minute marijuana addiction self-assessment below if you think you or someone you love might be struggling with a marijuana dependency. The evaluation consists of 11 yes or no questions that are intended to be used as an informational tool to assess the severity and probability of a marijuana use disorder. The test is free, confidential, and no personal information is needed to receive the result.

What is Marijuana?

Marijuana is a botanically-derived drug composed of the dried leaves, stems, seeds, and flowers of the Cannabis sativa or Cannabis indica plant.2 Colloquially referred to as pot, weed, herb, grass, bid, ganja, and Mary Jane, among others, marijuana is used in a variety of ways.2,3

Some individuals smoke it in hand-rolled cigarettes (called joints), in pipes or water pipes (called bongs), or in cigar wraps (called blunts).3 Others brew it in tea or mix it into “edibles” such as brownies, cookies, or candy.3 More recently, stronger versions of marijuana made from the plant’s resins have become available as extracts like “hash oil,” “wax,” or “shatter.”2 Smoking these resin extracts is known as “dabbing” and exposes the person to very high concentrations of delta-9-tetrahydrocannabinol (THC), the chemical in marijuana responsible for producing the intoxicating effects individuals feel.2,3

In 2020, nearly 18% of Americans aged 12 or older (or about 49.6 million people) reported having used marijuana within the prior year.3 Among this same group, just over 5% (or 14.2 million people) struggled with a cannabis use disorder, a diagnostic term for cannabis addiction.3 It has been estimated that people who begin using marijuana before age 18 may be 4–7 times more likely than adults to develop a marijuana use disorder.2

Short-Term Marijuana Effects

Marijuana’s effects set in nearly immediately when the drug is smoked as the THC and other chemicals pass from the lungs into the bloodstream, where it’s carried to the brain and throughout the rest of the body.2 If a person ingests cannabis that’s been baked into foods or brewed into beverages, on the other hand, the effects can be delayed from 30 minutes to 1 hour.3

Many people experience feelings of relaxation and euphoria with marijuana, but experiences vary.3 Feelings of anxiety, panic, mistrust, and general fear can occur when any individual uses marijuana, though such adverse effects are more commonly seen with higher, sometimes unexpectedly potent doses, or in individuals who don’t use the substance regularly.3

Other effects of marijuana use include:2,3

  • Altered sensory perception (such as an increase in sensitivity to sound).
  • Changes in the perception of time.
  • Mood changes.
  • Impaired body movement.
  • Impaired cognition and memory.
  • Increased heart rate.
  • Bloodshot eyes.

Individuals who use higher doses of marijuana may also experience psychotic symptoms such as hallucinations and delusions, though this may be more common after chronic, highly potent marijuana use.2

Long-Term Effects and Dangers of Marijuana Use

In addition to its more acute, or short-term drug effects, there is growing evidence that marijuana use may have lasting consequences on brain development—especially when marijuana use starts in adolescence when the brain is still developing—and can lead to other long-term physical and mental health problems, which may include.2,3

  • Respiratory difficulties. Marijuana smoke can irritate the respiratory tract—including the throat and lungs. Frequent use over a prolonged period increases the risk of problems such as cough, chronic bronchitis, increased risk and frequency of pneumonia, and other lung illnesses.
  • Pregnancy-related risks. Research indicates that children exposed to marijuana while they were in the womb were more likely to experience problems with attention, memory, and problem-solving. Other studies suggest that moderate amounts of THC can pass from a nursing mother to her child through breast milk, which could impact fetal brain development.
  • An increased risk of testicular cancer. A few studies show a link between adolescent marijuana use and an aggressive form of testicular cancer.
  • Severe cyclic nausea and vomiting. While rare, the condition, known as cannabinoid hyperemesis syndrome, can develop with chronic use.
  • Adolescent brain development issues. Some research indicates that regular marijuana use during adolescence—while the brain is still developing—can lead to impaired learning, memory, and impulse control. There is evidence that shows significant differences in brain development when heavy cannabis use starts before age 18. For adults over the age of 18, potentially persistent memory loss and declines in IQ may be linked to chronic or heavy marijuana use, though the evidence isn’t conclusive.
  • Psychiatric disorders. Several studies indicate a link between marijuana use and an increased risk of mental health disorders, such as schizophrenia, depression, and anxiety in individuals who are genetically predisposed. In fact, one study found that daily marijuana use, particularly at a young age, makes individuals with specific genes 7 times more likely to develop schizophrenia than people with the gene who do not use the drug. Additionally, marijuana has been shown to worsen symptoms associated with schizophrenia for those who already have the illness.
  • Addiction. Marijuana can be an addictive substance. Starting use during adolescence makes eventual compulsive misuse or the development of addiction more likely.
  • Increased risk of other substance use disorders. Some research suggests that marijuana use might be associated with an increased risk of future or concurrent addiction to other substances such as alcohol or nicotine.
  • Unknown consequences of high potency use. The trend toward higher-potency marijuana could pose additional, yet-unknown risks. Twenty years ago, the average THC content in confiscated marijuana was less than 4%. In 2018, it was more than 15%. Researchers do not yet know the full extent that these higher concentrations of THC will have on the body and brain, especially the developing brain.

Can You Overdose on Marijuana?

There are no reported cases of an adolescent or adult dying from using marijuana alone.2 However, with high doses of THC or by using more marijuana than intended, an individual may experience some very unpleasant side effects, such as paranoia, anxiety, and in rare cases, psychotic episodes that may include hallucinations or delusions.2

Marijuana Withdrawal

Chronic and frequent use of marijuana can lead some individuals to develop physical dependence. Dependence is the body’s physiological adaptation to the presence of marijuana, meaning the body has become so used to having marijuana in its system that when an individual stops, withdrawal symptoms emerge. Marijuana withdrawal symptoms can develop shortly after a person with significant physical dependence stops using the drug. Symptoms tend to peak within the first week after quitting and can last for up to 2 weeks.3 Withdrawal symptoms may include:3

  • Irritability.
  • Changes in mood.
  • Difficulty sleeping.
  • Decrease in appetite.
  • Cravings for marijuana.
  • Restlessness.

Marijuana Addiction

Compulsive marijuana use can impair several areas of life.3 Healthcare professionals use the 11 diagnostic criteria outlined in the Diagnostic and Statistical Manual, 5th edition (DSM-5) to make a diagnosis of a substance use disorder. An individual with a marijuana use disorder may have symptoms, including:4

  • Using more marijuana than intended.
  • Being unable to quit marijuana, despite trying.
  • Spending an increasing amount of time using, obtaining, and recovering from marijuana use.
  • Having marijuana cravings.
  • Continuing to use marijuana despite problems at home, work, or school.
  • Using marijuana even though it causes social or relationship problems.
  • Giving up other activities you used to enjoy in favor of using marijuana.
  • Using marijuana in physically dangerous situations.
  • Continuing marijuana use despite psychological or physical problems.
  • Requiring more marijuana to reach the same high.
  • Experiencing withdrawal symptoms if marijuana use is stopped.

Treatment for Marijuana Addiction and Outlook

If you or a loved one struggle with marijuana misuse or addiction, there is help available. Individuals with marijuana use disorders, especially adolescents, often also suffer from co-occurring psychiatric health conditions. Additionally, research shows that individuals with a marijuana use disorder may also be addicted to other substances, such as cocaine or alcohol.3

While there is no FDA-approved medication for the treatment of marijuana use disorder, individuals who receive this diagnosis may benefit from treatment that addresses polysubstance use, treats co-occurring mental health disorders, and utilizes behavioral therapies, including:3

  • Cognitive-behavioral therapy (CBT). CBT uses the idea that dysfunctional behaviors come from a dysfunctional way of thinking. CBT addresses this by teaching individuals the techniques to change their thoughts and improve coping skills to help individuals stay marijuana free.
  • Motivational enhancement therapy (MET). Also referred to as motivational interviewing, this counseling technique helps individuals resolve uncertainties about quitting marijuana by helping them come up with their own solutions. Rather than telling them what to do or change, the therapist helps them come up with solutions that will work best for them. This is done through guided conversations that involve reflections, empathy, and support.
  • Contingency management (CM). CM helps support positive behavior change, like abstaining from marijuana, by giving tangible rewards. The reward may come in the form of a gift card, movie tickets, or something else. Rewards continue with “good” behavior milestones—such as a drug-free urine test—until healthy habits are established.

The length and specifics of your treatment plan depend on the amount and frequency of cannabis use, co-occurring disorders, polysubstance use, and other factors particular to your story.3

Treatment for marijuana use is available. Find the program that fits your needs and make today the first day of your new life. Call American Addiction Centers (AAC) .

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