Teens, Brain Development, and Addiction

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Model of brain Many scientists who research addiction agree than people who use illegal drugs or abuse prescription drugs at an early age are more at risk of addiction than others who use the drug at a later age.  For example, a recent study concluded that alcohol abuse most often starts in the teenage years; of the 44,000 people surveyed, 47% of the alcoholics developed their addiction before age 21 and 15% before age 18. Researchers are investigating the anatomy of the brain in different stages of brain development in an effort to better understand what causes addiction.

Teenage brains are not fully developed with mature capabilities to guide risky behaviors. Many teens engage in risky behaviors because their brains are not developed to a point where they can use higher level decision-making thought processes that will allow them to stop.

Scientists and developmental experts used to think that key brain development took place in the first few years of life. Now, research that studied brain structure in children 12—16 years and in 23—30 years olds found marked differences in the brain’s frontal cortex—that part of the brain that interprets complex information.


Your Brain and a “Stop/Go” System

MRI of human brain
MRI showing a lateral view of the brain. http://en.wikipedia.org/wiki/Brain_imaging

Human brains are hard-wired for what researchers describe as a “Stop/Go” system.  A system likes this helps a species survive by having heightened responses to finding food and seeking shelter. Some stimuli produce a “Go” signal to the brain in response to something that is pleasurable to the person. In a mature brain the responses can be filtered out and put into a perspective that is more realistic—basically, the brain considers the advantages and disadvantages of the response. For some responses, the mature brain is capable of putting a “Stop” to the response because it is detrimental to the person.

Teens brains are still developing. They may react to the “Go” stimulus, but they may not correctly consider the clues that can trigger the “Stop” signal. This can lead to risky behaviors and the consequences that can come with them.

Subtle differences in brain anatomy and development have been identified using brain-imaging techniques. Researchers such as Dr. Anna Childress with the University of Pennsylvania School of Medicine have studied brain biology with drug addictions and has found subtle differences which may lead to poor impulse control—the “Stop” mechanism doesn’t work well.


Lower Numbers of Receptors

radiologic imaging of the brain and ganglia
Axial imaging of the brain and ganglia. http://en.wikipedia.org/wiki/Brain_imaging

Imaging of addicts’ brains show a lower number than average of receptors for dopamine—a brain chemical that makes a person feel good. A person with fewer numbers of receptors may take a drug in order to compensate for a lack of receptors that can make them feel more satisfied, happy, or confident.

Researchers do not yet know if this difference is inherited. There seems to be a link between genetics and frequency of addiction, but studies of identical twins raised separately also indicate the environmental factors play a key role in the additive behaviors.

So, is it genetics or our environments that lead some people to become addicts while others do not? Researchers and drug addiction scientists will continue to study the question and the problem of addiction and try to answer that important question. One day, there may be a screening test that will accurately predict those who are more susceptible to addictive behaviors. With proper treatment with optimal timing, the many consequences of drug abuse could be avoided.

 Why Is It So Hard To Quit?  (and not just for teens)

It is so hard to quit using drugs because addiction is a brain disease. Drugs change the way your brain works.

A person on drugs has a harder time making good decisions. They cannot process information correctly and may participate in risky behaviors they would never do if they weren’t drunk or high. Risky behaviors may have permanent negative consequences. Driving while under the influence of alcohol (or other drugs) can result in expensive legal fees and loss of a driver’s license; sexual activity can result in STD (sexually transmitted disease) infections and pregnancy. A tendency to violent behaviors can result in injuries and arrests. Long-term drug abuse can result in drug abuse disorders.

After a person is addicted, the brain resists withdrawal from the drug. The person craves the drug to the point that he physically and psychologically “needs” the drug. Withdrawal symptoms can be severe and the addict continues to abuse the drug to feel better. The cycle—and consequences—continue.