Health Issues

Using marijuana is harmless.   MYTH

Adolescent's Brain Development & Use
Facts for Families


Persistent Cannabis Users Show A Significant IQ Drop  between Childhood and Midlife


This slide shows the results of one such study. These are MRI scans of the corpus callosum, the bundle of fibers connecting the two brain hemispheres, allowing the two hemispheres to communicate and work in a coordinated way. Young adult males who smoked marijuana daily (and started at an average age of 15 yrs) were scanned along with age-matched on-users. All had low levels of alcohol use.
The different regions of the corpus callosum fibers are shown in bright colors on these two scans. The circled area on the scan of the daily user (right) shows thinner corpus callosum fibers than the scan of the non-user (left), indicating that there are white matter integrity issues for the daily user.   Poorer communication across different parts of the brain that need to work together for proper cognitive function may be one cause of cognitive disorders such as schizophrenia.

Click on photo for section on PowerPoint section on Mental Health.

The Teen Brain on Marijuana  PowerPoint highlights the affects of marijuana on the brain by identifying studies that show decreases IQs, why it is addictive, how the brain changes, increases liklihood of mental health issues ...

Short-Term Affects:
  • Euphoria (high). THC activates the reward system in the same way that nearly all drugs of abuse do: by stimulating brain cells to release the chemical dopamine.
  • Memory impairment. THC alters how information is processed in the hippocampus, a brain area responsible for memory formation, causing problems with short-term memory as well as difficulty with complex tasks requiring sustained attention/concentration. Prolonged use could therefore affect learning skills and academic achievement.
  • Increased appetite ("munchies").
  • Increased heart rate.
  • Dilation (expansion) of the blood vessels in the eyes, making them look red or bloodshot.
  • Adverse mental reactions in some. These include anxiety, fear, distrust, or panic, particularly in those who are new to the drug or who are taking it in a strange setting; and acute psychosis, which includes hallucinations, delusions, paranoia, and loss of the sense of personal identity.

In 2012, THC concentrations in marijuana averaged nearly 15 percent, compared to around 4 percent in the 1980s. This is based on analyses of marijuana samples confiscated by law enforcement agencies. So what does this actually mean?

  • For a new user, it may mean exposure to higher concentrations of THC, with a greater chance of an adverse or unpredictable reaction. In fact, increases in potency may account for the rise in emergency department visits involving marijuana use.
  • For experienced users, it may mean a greater risk for addiction if they are exposing themselves to high doses on a regular basis.

More information on affects of Marijuana Use

Information from the Center for Substance Abuse Research