What Happens to Your Brain When You Take Drugs?
Drugs contain chemicals that tap into the brain’s communication system and disrupt the way nerve cells normally send, receive, and process information. There are at least two ways that drugs cause this disruption: (1) by imitating the brain’s natural chemical messengers and (2) by overstimulating the “reward circuit” of the brain.
Some drugs (e.g., marijuana and heroin) have a similar structure to chemical messengers called neurotransmitters, which are naturally produced by the brain. This similarity allows the drugs to “fool” the brain’s receptors and activate nerve cells to send abnormal messages.
Other drugs, such as cocaine or methamphetamine, can cause the nerve cells to release abnormally large amounts of natural neurotransmitters (mainly dopamine) or to prevent the normal recycling of these brain chemicals, which is needed to shut off the signaling between neurons. The result is a brain awash in dopamine, a neurotransmitter present in brain regions that control movement, emotion, motivation, and feelings of pleasure. The overstimulation of this reward system, which normally responds to natural behaviors linked to survival (eating, spending time with loved ones, etc.), produces euphoric effects in response to psychoactive drugs. This reaction sets in motion a reinforcing pattern that “teaches” people to repeat the rewarding behavior of abusing drugs.
As a person continues to abuse drugs, the brain adapts to the overwhelming surges in dopamine by producing less dopamine or by reducing the number of dopamine receptors in the reward circuit. The result is a lessening of dopamine’s impact on the reward circuit, which reduces the abuser’s ability to enjoy not only the drugs but also other events in life that previously brought pleasure. This decrease compels the addicted person to keep abusing drugs in an attempt to bring the dopamine function back to normal, but now larger amounts of the drug are required to achieve the same dopamine high—an effect known as tolerance.
Long-term abuse causes changes in other brain chemical systems and circuits as well. Glutamate is a neurotransmitter that influences the reward circuit and the ability to learn. When the optimal concentration of glutamate is altered by drug abuse, the brain attempts to compensate, which can impair cognitive function. Brain imaging studies of drug-addicted individuals show changes in areas of the brain that are critical to judgment, decision making, learning and memory, and behavior control. Together, these changes can drive an abuser to seek out and take drugs compulsively despite adverse, even devastating consequences—that is the nature of addiction.
Why Do Some People Become Addicted While Others Do Not?
No single factor can predict whether a person will become addicted to drugs. Risk for addiction is influenced by a combination of factors that include individual biology, social environment, and age or stage of development. The more risk factors an individual has, the greater the chance that taking drugs can lead to addiction. For example:
- Biology. The genes that people are born with—in combination with environmental influences—account for about half of their addiction vulnerability. Additionally, gender, ethnicity, and the presence of other mental disorders may influence risk for drug abuse and addiction.
- Environment. A person’s environment includes many different influences, from family and friends to socioeconomic status and quality of life in general. Factors such as peer pressure, physical and sexual abuse, stress, and quality of parenting can greatly influence the occurrence of drug abuse and the escalation to addiction in a person’s life.
- Development. Genetic and environmental factors interact with critical developmental stages in a person’s life to affect addiction vulnerability. Although taking drugs at any age can lead to addiction, the earlier that drug use begins, the more likely it will progress to more serious abuse, which poses a special challenge to adolescents. Because areas in their brains that govern decision making, judgment, and self-control are still developing, adolescents may be especially prone to risk-taking behaviors, including trying drugs of abuse.
Drugs and Substances We Treat Include:
Alcohol’s withdrawal syndrome is so severe that it can cause death, and its effects on the brain’s reward system cause well-documented and intense craving in heavy drinkers.
Heroin affects opioid receptors throughout the body and mimics endorphins, reducing pain and causing pleasure. Pair that with nasty withdrawal symptoms and high fat solubility and you have the most addictive drug in the world.
Although crack cocaine and powder cocaine have similar chemical compositions and effects, smoking processed crack causes a faster, higher rush that lasts for less time. The intensity of the high combined with the efficient method of ingestion—smoking—are the big reasons why addiction rates are dramatically higher for crack than they are for snorted powder.
There are a shocking 50,000,000 nicotine addicts in the US, and one in every five deaths nationwide are the result of smoking.
A addict getting treated with methadone will quickly become resistant to its euphoric effects and use it to keep heroin withdrawal symptoms at bay. The problem is this: tolerance to methadone is a sign of an addiction to methadone.
Crystal methamphetamine imitates the reward chemical dopamine and the alertness chemical norepinephrine, causing your neurons to release more of both—all the while training your brain to want them more. The drug can damage dopamine- and norepinephrine-releasing neurons, which leads to a drastic decrease in their production, thereby making you crave more meth.
After you use cocaine, your brain reduces the number of dopamine receptors in this region, figuring it’s already got plenty of it. Because there are now fewer receptors, stopping the drug makes you crave it. The fast method of use (snorting), short high (less than an hour) and rapid tolerance put it in the top ten addictive drugs.
Adderall users beware: Regular amphetamine might not be quite as addictive as meth, but because it acts on the same reward circuit, it still causes rapid tolerance and desire for more if used regularly or in high doses. Quitting cold turkey can cause severe depression and anxiety, as well as extreme fatigue.
(Valium, Xanax, Klonopin ) Because benzodiazepines cause rapid tolerance, quitting cold turkey causes a multi-symptom withdrawal that includes irritability, anxiety and panic attacks.
Cannabinoids / Marijuana
The psychoactive element in this class of drugs is THC. Marijuana carries a high risk for abuse and over time can result in short-term memory loss, respiratory issues, depression and anxiety. Users of synthetic marijuana, also called “Spice” or “K2,” have also shown symptoms of psychosis.
Hallucinogenic “trips” are highly unpredictable with unintended physical and psychological side effects such as elevated heart rate, frightening illusions, psychosis and death.
Steroids interrupt the body’s endocrine system and can cause negative side effects such as aggression and organ damage. In women, steroid use can lead to excessive hair growth or development of male sexual characteristics. In men, it can cause shrinkage of the testicles, baldness and infertility.
These substances depress the central nervous system and commonly cause dizziness, light-headedness and poor motor control. Inhalant abuse leads to brain damage, organ failure and death.