What Is Addiction & Who Does It Affect?

Addiction, clinically referred to as substance use disorder, is a complex, chronic, and potentially fatal brain disease that affects millions of people. Addiction has long been misunderstood and stigmatized in society, with many who believe that addiction is a choice and can be easily fixed. This couldn’t be farther from the truth. More than 23 million adults in the United States have struggled with problematic drug use. Addiction costs the United States $600 billion annually, and evidence based treatment can help to reduce this cost.

Addiction results from many biological, psychological, interpersonal and social factors. What may start as recreational and social drinking or drug use can sometimes lead to misuse or addiction. Like other diseases such as diabetes, heart disease, or cancer, addiction is caused by a combination of behavioral, environmental, and biological factors. Genetics likely play an important part in the development of substance use disorders, however they are not the only factor. Many different life experiences can lead to the development of a substance use disorder.

Addiction involves the continued use of substances despite negative consequences. It often includes impairment of functioning that can impact everyday decisions. Some signs of substance use disorder include:

• Strain in family or social relationships
• Decline in physical health
• Failure to fulfill major role obligations at work, home or school
• Legal trouble
• Financial trouble

Depending on the substance, signs of addiction can be different. Learn more about signs of addiction for those using any or a combination of the following:

Alcohol

Methamphetamine

Heroin

Cocaine

Xanax

Opioids

Addiction affects the brain on many levels. While basic enjoyable activities release dopamine in the brain, drugs and alcohol can release a surge of dopamine and cause a sense of euphoria. Over time, someone who is in active addiction will develop a tolerance, and therefore need more and more of the substance to achieve the same desired effects. This can lead to the experience of using not only to feel the substance’s euphoric effects but to also feel “normal.”

In active addiction, the brain categorizes substance use as a survival mechanism. When people in active addiction experience cravings, the feeling of “needing” to drink or use comes from the midbrain, which is responsible for survival and rewards.

Prolonged drug and alcohol use can also affect communication between the midbrain and the prefrontal cortex, which allows the ability to problem solve, make decisions, and exert self-control. Prolonged substance use alters the brain and reduces the person’s ability to make sound decisions and diminishes impulse control.

Substance Use Disorder, Substance Abuse, and Stigma: Why the Words Matter

You will see several terms for what this page calls addiction. Substance use disorder, usually shortened to SUD, is the clinical diagnosis. It is graded mild, moderate, or severe by how many of eleven symptoms apply within a year, which is how NIAAA describes the current diagnostic manual for alcohol: two to three symptoms is mild, four to five moderate, six or more severe. The same framework applies to other drugs. "Addiction" is the everyday word and generally maps to the moderate and severe end. "Substance abuse" was an older diagnostic category that the manual dropped in 2013; it survives in agency names and in conversation, but clinicians now avoid it because it describes the person as an abuser rather than describing a condition.

That last point is the reason language gets attention. Stigma is the set of negative beliefs and judgments attached to a condition, and it shows up three ways: from other people (an employer who assumes the worst, a family member who calls it a choice), from institutions (rules that treat a health condition as a moral failing), and from inside (the shame that keeps someone from picking up the phone). Surveys and clinical experience both point to stigma as one of the main reasons people delay asking for help, sometimes for years. The myths section below takes apart the most common versions.

Two practical things follow. First, you do not need to hit every marker or match anyone's picture of an addict to qualify for help; a mild disorder is still a disorder that treatment can address. Second, people in recovery who are not currently using illegal drugs have legal protections in employment and housing under the Americans with Disabilities Act, including people taking prescribed medication such as buprenorphine or methadone. Our page on confidentiality in rehab covers those protections and who can learn that you went to treatment.