Back to Toolkit Home

Why do people abuse alcohol and drugs?

People use substances like alcohol, tobacco, prescription or over-the-counter medications, or illicit drugs (e.g. marijuana, cocaine, methamphetamine, or heroin) to alter the way they feel. Alcohol or drugs are often used to self-medicate the symptoms of depression or anxiety. However, instead of improving their situation, people often become addicted to the substance used.

Although substance abuse may lead to addiction, the 2 terms have different meanings. You can use the CAGE Tool to help you assess whether you may have a substance use disorder.

Substance abuse refers to the harmful use of illegal substances, legal substances such as alcohol, or medications (e.g. taking more than prescribed). Not everyone who uses or abuses drugs becomes addicted to them. However, ongoing substance abuse can ultimately lead to drug dependency, or addiction.

Drug addiction, or substance use disorder, is a brain disease that is characterized by compulsive drug seeking and use despite the many physical, financial, social, and legal risks involved. When someone is addicted to a substance, they continue taking it, even though it may cause harm. Excessive drug use overstimulates the brain’s “reward circuit” with the chemical messenger dopamine, leading someone to take a drug over and over again. The brain continues to adjust to this excess dopamine, which reduces the high a person feels over time. This often leads to brain changes that interfere with someone’s ability to control their use of a particular substance. Motivational factors such as school, work, family life, daily activities, and self-care lose their importance, and the drug becomes the only way the addict can find any happiness or relief.

Addiction causes changes in other brain chemical systems and circuits as well, affecting functions that include:

  • Learning
  • Judgment
  • Decision-making
  • Stress
  • Memory
  • Behavior

It is the brain’s desire for more that defines drug addiction, and explains why, like alcoholism, drug addiction is a disease, not a lack of willpower.

Behavioral changes, including:

  • Drop in attendance and performance at work or school
  • Frequently getting into trouble (fights, accidents, illegal activities)
  • Using substances in dangerous situations such as while driving
  • Engaging in secretive or suspicious behaviors
  • Changes in appetite or sleep patterns
  • Personality changes
  • Mood swings, irritability, or angry outbursts
  • Lack of motivation
  • Fear, anxiety, or paranoia

Physical changes, including:

  • Bloodshot eyes and abnormal pupil size
  • Sudden weight loss or weight gain
  • Declining physical appearance
  • Tremors, slurred speech, or poor coordination

Social changes, such as:

  • Change in friends or favorite activities
  • Legal problems related to substance use
  • Financial problems

Rates of past year substance use disorder in US adults are about 12 % for alcohol and 2-3 % for illicit drugs. Scientists believe that several factors can increase a person’s risk of developing an addiction, including:

  • Genetics – Hereditary factors may account for up to 60% of a person’s propensity to become addicted.
  • Other brain illnesses – Individuals with depression or bipolar disorder face a significantly increased risk of addiction.
  • Environment – A person’s family life and social interactions can be contributing factors. If exposed to drug or alcohol abuse of a parent or older sibling as a child an individual is at greater risk of developing their own drug problem as an adult. The same is true of people who are exposed to drug use by friends or peers in adolescence.
  • Age of first use – Research also indicates that the earlier a person begins to use drugs, the more likely their use will progress to abuse.
  • Method of use – Even the way a person’ uses drugs can have an impact on their vulnerability to developing an addiction. For example, drugs that are injected or smoked impact the brain within seconds, and their initial impact can fade quickly. Scientists believe this “roller coaster” effect produces greater risk of subsequent drug abuse by creating a constant cycle of trying to bring back the initial pleasure and avoid the subsequent discomfort.

Established methods for treating drug addiction have been shown to be effective in individuals who are motivated to recover and are committed to getting the support they need. Success in recovery from addiction requires a significant lifestyle change, and constant daily effort to remain sober and drug-free.

There are several options available to address dependence on alcohol or other substances:

  • Intensive hospital treatment, either inpatient or outpatient, may be recommended to break the cycle of dependence.
  • Individual or group psychotherapy
  • Many people find 12-step groups such as Alcoholics Anonymous or Narcotics Anonymous to be extremely beneficial in overcoming substance abuse and living in recovery.
  • There are some medications available to help patients overcome the symptoms of substance dependence. Most often, medications are used in combination with behavioral therapy to yield the best results.

Alcoholism and drug addiction are chronic diseases, meaning that they must be managed over a lifetime. There is always the possibility that the disease will relapse, even if the individual remains sober and drug-free for a long period of time. It is important not to associate relapse with failure. Instead, relapse indicates that the individual’s treatment program should be reevaluated and perhaps revised to ensure ongoing recovery.

Merikangas, K. R., & McClair, V. L. (2012). Epidemiology of substance use disorders. Human genetics, 131(6), 779-789

Mental, H. S. A. U., & Office of the Surgeon General (US. (2016). Facing addiction in America: The Surgeon General's report on alcohol, drugs, and health.

Swendsen, J., Conway, K. P., Degenhardt, L., Glantz, M., Jin, R., Merikangas, K. R., ... & Kessler, R. C. (2010). Mental disorders as risk factors for substance use, abuse and dependence: results from the 10‐year follow‐up of the National Comorbidity Survey. Addiction, 105(6), 1117-1128.