Marijuana

Marijuana is the dried leaves and flowers of the Cannabis sativa or Cannabis indica plant. Of the more than 500 chemicals in marijuana, delta-9-tetrahydrocannabinol, known as THC, is responsible for many of the drug's psychotropic (mind-altering) effects. It's this chemical that distorts how the mind perceives the world. In other words, it's what makes a person high.

Strength and Potency

The amount of THC in marijuana has increased over the past few decades. In the early 1990s, the average THC content in marijuana was less than four percent. It is now about 15 percent and much higher in some products such as oils and other extracts.

Smoking, eating or vaping extracts and resins from the marijuana plant with high levels of THC is on the rise. There are several forms of these extracts, such as hash oil, budder, wax, and shatter. These resins have three to five times more THC than the plant itself, some products reaching as much as 99% THC.

Eating, smoking or vaping it (also called dabbing) can deliver dangerous amounts of THC and has led some people to seek treatment in the emergency room with symptoms, including nervousness, shaking and psychosis (having false thoughts or seeing or hearing things that aren't there). There have also been reports of people injured in fires and explosions caused by attempts to extract hash oil from marijuana leaves using butane (lighter fluid).

Scientists do not yet know what this increase in potency means for a person's long-term health.

what happens to your brain

All drugs change the way the brain works by changing the way nerve cells communicate. Nerve cells, called neurons, send messages to each other by releasing chemicals called neurotransmitters. These neurotransmitters attach to molecules on neurons called receptors. Marijuana affects this signaling process.

When marijuana is smoked or vaporized, THC quickly passes from the lungs into the bloodstream, which carries it to organs throughout the body, including the brain. Its effects begin almost immediately and can last from one to three hours. This can affect decision making, concentration, and memory for days after use, especially in people who use marijuana regularly.

If marijuana is consumed in foods or beverages, the effects of THC appear later—usually in 30 minutes to 1 hour—and may last for many hours. Some people consume more and more waiting for the "high" and end up in the emergency room with uncomfortable symptoms from too much THC.

an image listing all the effects of marijuana

Short term effects:

  • Impaired judgment, slowed reflex response
  • Compromised memory
  • Reduced motor function
  • Increased heart rate
  • Blood vessel expansion
  • Nausea and vomiting
  • Wheezing and coughing
  • Anxiety, paranoia

Long Term effects:

  • Learning and memory problems
  • Sleep problems
  • Risk of addiction
  • Risk of chronic cough, bronchitis
  • Risk of schizophrenia (in some with higher genetic risk)
  • Increased risk of liver damage
  • Reduction in overall life satisfaction

Studies have shown that marijuana use can alter the structure of the teenage brain, specifically in areas that handle problem solving and memory.