Marijuana And The Brain

Marijuana and the Brain

Marijuana effects many different parts of the brain, which causes ​short term and long term effects. 

Short Term Effects

The short term effects of marijuana can differ depending on how you are using the drug. When smoking or inhaling marijuana, the effects will hit within about 5-10 minutes. Edibles will begin to effect the brain in roughly 45 minutes to an hour. The brain has receptors that are very similar to THC found in Marijuana which play a big role in brain development and function. THC in marijuana takes over those brain receptors and can drastically change your mood, and behavior. THC causes your eyes to dilate which can cause you to see brighter colors and also a slowed/skewed since of vision. THC alters your senses and and can impair body movement as well as difficulty thinking and problem solving. Impaired memory and an altered sense of time. All of these effects which are caused by marijuana are due to the reaction of the THC and brain receptors.

Mental Effects

Long-term marijuana use has been linked to mental illness in some users, such as:

  • temporary hallucinations—sensations and images that seem real though they are not
  • temporary paranoia—extreme and unreasonable distrust of others
  • worsening symptoms in patients with schizophrenia (a severe mental disorder with symptoms such as hallucinations, paranoia, and disorganized thinking)

Marijuana use has also been linked to other mental health problems, such as:

  • depression
  • anxiety
  • suicidal thoughts among teens

Is Marijuana Addictive?

Contrary to common belief, marijuana can be addictive. Research suggests that about 1 in 11 users becomes addicted to marijuana (Anthony, 1994; Lopez-Quintero 2011).This number increases among those who start as teens (to about 17 percent, or 1 in 6) (Anthony, 2006) and among people who use marijuana daily (to 25-50 percent) (Hall & Pacula, 2003).

How can people get treatment for marijuana addiction? Long-term marijuana users trying to quit report withdrawal symptoms that make quitting difficult. These include:

  • grouchiness
  • sleeplessness
  • decreased appetite
  • anxiety
  • cravings

Behavioral support has been effective in treating marijuana addiction. Examples include therapy and motivational incentives (providing rewards to patients who remain substance free). No medications are currently available to treat marijuana addiction. However, continuing research may lead to new medications that help ease withdrawal symptoms, block the effects of marijuana, and prevent relapse.

Long Term Effects

The long term effects of marijuana use can seriously affect brain development. When marijuana users begin using as teenagers, the drug may reduce thinking, memory, and learning functions and affect how the brain builds connections between the areas necessary for these functions.

Marijuana’s effects on these abilities may last a long time or even be permanent.
For example, a study showed that people who started smoking marijuana heavily in their teens and had an ongoing cannabis use disorder lost an average of eight IQ points between ages 13 and 38. The lost mental abilities did not fully return in those who quit marijuana as adults. Those who started smoking marijuana as adults did not show notable IQ declines (Meier, 2012).
A Rise in Marijuana’s THC Levels) The amount of THC in marijuana has been increasing steadily over the past few decades (Mehmedic, 2010). For a new user, this may mean exposure to higher THC levels with a greater chance of a harmful reaction. Higher THC levels may explain the rise in emergency room visits involving marijuana use.
The popularity of edibles also increases the chance of users having harmful reactions. Edibles take longer to digest and produce a high. Therefore, people may consume more to feel the effects faster, leading to dangerous results.
Dabbing is yet another growing trend. More people are using marijuana extracts that provide stronger doses, and therefore stronger effects, of THC (see "Marijuana Extracts").
Higher THC levels may mean a greater risk for addiction if users are regularly exposing themselves to high doses.
What are the other health effects of marijuana? Marijuana use may have a wide range of effects, both physical and mental.
Physical effects

  • Breathing problems. Marijuana smoke irritates the lungs, and frequent marijuana smokers can have the same breathing problems that tobacco smokers have. These problems include daily cough and phlegm, more frequent lung illness, and a higher risk of lung infections. Researchers still do not know whether marijuana smokers have a higher risk for lung cancer.
  • Increased heart rate. Marijuana raises heart rate for up to 3 hours after smoking. This effect may increase the chance of heart attack. Older people and those with heart problems may be at higher risk
  • Problems with child development during and after pregnancy. Marijuana use during pregnancy is linked to increased risk of both brain and behavioral problems in babies. If a pregnant woman uses marijuana, the drug may affect certain developing parts of the fetus’s brain. Resulting challenges for the child may include problems with attention, memory, and problem-solving. Additionally, some research suggests that moderate amounts of THC are excreted into the breast milk of nursing mothers. The effects on a baby’s developing brain are still unknown.

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