OTC and Prescription Drug Abuse Slideshow Pictures Health Risks of Alcohol Abuse Slideshow Pictures

Medical Author:

Maureen C Nash, MD, MS

Coauthor:

Jessica B Johnson

Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Addiction Causes

Addiction or substance abuse is a complex brain disease. A person with an addiction experiences cravings that persist even in the face of extremely negative consequences. During a craving, a person with an addiction misses the habit-forming drug terribly, and often he or she experiences symptoms of withdrawal.

Evidence strongly suggests that genetic susceptibilities and biological traits play a role in addictions; however, the development of an addiction is also shaped by a person's environment (for example, a person with alcoholism cannot become addicted without access to alcohol). The "addictiveness" of a drug is related to how strongly the drug activates the reward circuits in the brain. For instance, when the methamphetamine found on the street is purer (meaning that it stimulates the dopamine reward circuits more), then the number of first-time drug users who become drug abusers is higher.

Addictive substances or behaviors change the reward circuits in the brain. In other words, the brain responds to the addictive substance in the same way that it responds to very pleasurable experiences. This explains, in a general sense, why people with addictions sometimes forsake all other life activities and obligations and even their own health in pursuit of the addictive substance.