What is Drug Addiction?

Learn how drug addiction can alter and damage brain function

drug addiction

Researchers and scientists call drug addiction a "brain disease," primarily because drugs change the brain, its chemistry, and how it functions - or fails to function.

Putting the words "addiction" and "disease" in the same sentence hasn't always been the norm. For most of the 20th century, most people, including doctors and other health care professionals, considered addiction to be a moral weakness, a personal failing - a sign of unsound character.

Over the last few decades, scientific advances made in brain physiology and functioning have dispelled these beliefs. Additionally, technological advances in non-invasive brain imaging techniques show, unequivocally, the physical manifestations and obstructive nature of the disease.

Those addicted to drugs start out as drug abusers, sampling and experimenting with drugs. Over time, for some sooner rather than later, their bodies become dependent on the drugs, functioning abnormally because of profound changes in the brain's cells and intricate circuitry. Using a simplistic analogy, the effect of drugs on brain cells mimics malfunctioning smoke detectors, detectors randomly going off without any signs of smoke or fire.

Unlike smoke detectors, however, addicts don't have any easy way to "turn off" malfunctioning brain circuitry. Addictions are complicated, and require long-term rehabilitation to manage. But the good news is that professionals now treat addiction as a serious medical condition, helping individuals manage its effects, and recover from its harmful ramifications.

The addictive brain

The brain is a 3-pound control center for emotions, feelings, thoughts, cognition, behaviors, and movements. One of the main components of that control center, a brain neurotransmitter called dopamine, plays a major role in motivation, pleasure, and learning. Researchers now understand how drugs alter dopamine levels, interfering with the way nerve cells typically send, receive, and process information.

meth and the brain

Healthy brains naturally produce neurotransmitters to facilitate communication between the brains' nerve cells, called neurons. Dopamine is a chemical that informs us of what's good, or pleasurable, such as steak cooking on an outside grill. If you're hungry and you smell the steak, certain neurons start kicking out dopamine, sending the chemical substance to other neurons that have dopamine receptors. Some of the dopamine, however, doesn't get picked up by these receptors, and the original neurons must take back, or reuptake, the excess dopamine.

When individuals use illicit drugs, the brain's finely-tuned neurotransmission process starts to work differently - abnormally. Drugs such as cocaine cause neurons to pump out dopamine in skyrocketing amounts, amounts larger than the neurons can handle, disrupting the normal processing and recycling of dopamine. These drugs can pump out 2 to 10 times the natural amount of dopamine, and the "pleasurable" sensations last much longer than natural levels of dopamine. Communication messages sent from the neurons are out of proportion, disrupting other bodily systems.

Other drugs, such as marijuana and heroin simulate the chemical structure of neurotransmitters, "tricking" neuron receptors into receiving them, and activating nerve cells. Even though the chemicals from these drugs look like naturally occurring neurotransmitters, they produce much different effects - again sending out abnormal messages to other parts of the brain and body. Long-term use of these drugs dramatically alters neurons, brain circuits, and the overall health of the brain.

Drug Tolerance

One of the most pernicious affects of drugs on the brain is the development of tolerance. The constant surges in abnormally high levels of dopamine (other neurotransmitters are also increased) cause the brain to produce less naturally occurring dopamine. When these low levels of natural dopamine are released, the brain no longer responds as it did before, and the ability to experience pleasure "naturally" disappears. This leaves many addicts lifeless, depressed, and feeling "low."

Previous activities that produced natural "highs," such as listening to music, art making, hiking, going to movies, or enjoying the company of friends and family, no longer trigger normal, pleasurable feelings. To "lift" their spirits, addicts must now take drugs to simply try and get their dopamine levels to normal levels. To reach a state of euphoria, similar to their first usage of drugs, they must continually take larger and larger amounts of the drug.

Craving

The pleasure and reward system instigated by dopamine is one of the body's main survival mechanisms. The brain's intricate circuitry functions in such a way as to keep telling our bodies what is needed to sustain life - such as eating, or having sex. In this way, dopamine levels trigger our bodies in such a way to refocus our attention to things that are not only pleasurable, but things we need as well.

When addicts deluge their brain's circuitry with drugs, it retrains the brain to focus exclusively on the drugs, tricking addicts to think that they need the drugs to survive. Addicts' brains mistakenly think that drugs are required just as satisfying other bodily needs are required.

Intense, sometimes uncontrollable drug cravings, are one of the signature hallmarks of drug addiction. Addicts often go through extremely unpleasant withdrawal or detoxification when drugs are withheld, hard to find, or they simply decide to stop using and begin a substance abuse treatment program. Many need additional medication to help control these cravings.

Possible causes of addiction

Researchers are still trying to understand why some individuals can use, even abuse, drugs and not become addicted, while others become addicted on initial usage. (For an explanation on abuse, dependency and addiction, see What is Substance Abuse and Addiction?)

While an exact reason for addiction still eludes researchers, their emphasis on studying healthy and unhealthy levels of dopamine, and how the brain responds to it, has provided new insights and breakthroughs. For example, brain researchers now know that some individuals are born with lower amounts of dopamine receptors than others. This could mean drugs that increase levels of dopamine, or dopamine-like substances, cause some individuals to more easily become addicted.

Other researchers focus on socioeconomic factors, or underlying mental illnesses, as leading to or contributing to the disease. Poverty and extreme stress are linked to drug addiction. And the high rate of mental disorders, such as depression, anxiety (see Anxiety), and bipolar disorder (see Bipolar Disorder), that often accompany addiction strongly suggest a possible correlation to the disease.

Often, it's the complex combination of many physical, emotional, and psychological factors that cause many individuals to become addicted. Fortunately, substance abuse counselors and other professionals working at substance abuse treatment centers are able to help these individuals recover from addiction. (For more information on substance abuse treatment centers, see Substance Abuse Treatment Centers.)

If you have a desire to help others with addiction diseases, you should consider a career in substance abuse and behavioral disorders. Many schools offer psychology degrees with specializations in this field, leading to careers as substance abuse counselors. For more information on these degrees, request information from the schools offering psychology or counseling degree programs.

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  • With 100,000+ students, it's the largest private, nonprofit university in the nation.
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  • Offers over 230 programs online, from the certificate to the doctoral level.
  • The student-faculty ratio is 25:1, and 42.3% of its classes have fewer than 20 students.
  • The average freshman retention rate, an indicator of student satisfaction, is 76.5%.
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  • With 100,000+ students, it's the largest private, nonprofit university in the nation.
  • Since 1971, its mission has been to develop Christ-centered men and women with the values, knowledge, and skills essential for impacting tomorrow’s world.
  • Offers over 230 programs online, from the certificate to the doctoral level.
  • The student-faculty ratio is 25:1, and 42.3% of its classes have fewer than 20 students.
  • The average freshman retention rate, an indicator of student satisfaction, is 76.5%.
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  • Currently holds more than 500 professional alliances, including 19 of the top Fortune 100 companies.
  • Potential students may preview a free, one-week mini course to get an accurate impression of the student experience.
  • Courses are taught by expert faculty, with 86% of professors possessing a doctoral degree.
  • Offers credit for prior experience and learning, as well as scholarships, accelerated programs, and several other ways to help reduce tuition costs.
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  • Offers 24/7 student services, including financial aid help, course registration, and career counseling.
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  • Founded in 1949, Grand Canyon University is a premier, private, accredited, nondenominational Christian university located in Phoenix, Arizona
  • Its student-faculty ratio is 16:1 and 33.9% of its classes have fewer than 20 students.
  • As a Christian university, the school encourages students to find their purpose in Christ, with an emphasis on applying Christian values and ethics to the workplace.
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  • Founded in 1949, Grand Canyon University is a premier, private, accredited, nondenominational Christian university located in Phoenix, Arizona
  • Its student-faculty ratio is 16:1 and 33.9% of its classes have fewer than 20 students.
  • As a Christian university, the school encourages students to find their purpose in Christ, with an emphasis on applying Christian values and ethics to the workplace.
  • 65% of students have cars on campus, and alcohol is not permitted for students of legal age.
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  • All incoming freshman students are given laptop computers.
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Indiana Wesleyan University is an evangelical Christian comprehensive university that is committed to liberal arts and professional education. U.S. News & World Report ranks Indiana Wesleyan University as "one of the best Master's universities in the Midwest."

Indiana Wesleyan University is an evangelical Christian comprehensive university that is committed to liberal arts and professional education. U.S. News & World Report ranks Indiana Wesleyan University as "one of the best Master's universities in the Midwest."

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  • Ranked one of the Best Online Bachelor’s Programs in 2014 by U.S. News & World Report.
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  • Ranked one of the Best Online Bachelor’s Programs in 2014 by U.S. News & World Report.
  • Offers a no-obligation, 3-week trial period where students may determine if the university is right for them before they commit to it.
  • Strives to be a student’s partner in lifelong learning; committed to helping them achieve their goals.
  • Serves students of all ages, from first-graders learning to read to professionals seeking postgraduate training.
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  • Provides students the opportunity to train at home in their spare time to get their high school diploma, train for a new career, or enhance current skills.
  • Member of the United States Distance Learning Association (USDLA), the Canadian Network for Innovation in Education (CNIE), and the International Council for Open and Distance Education (ICDE).
  • Features a fully flexible schedule with no classes to attend, leaving the study pace up to the student.
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