Addiction & Substance Abuse

Edmund Murphy
Dr. Samantha Miller
Written by Edmund Murphy on 25 August 2021
Medically reviewed by Dr. Samantha Miller on 02 December 2024

Addiction comes in many forms and can affect people in different ways and to different things such as alcohol, drugs, and behaviors. However, the universal characteristic of addiction is its difficulty to get over once it takes hold. Below we look at the effects of addiction, the reasons it takes hold, and how it can be beaten.

Key takeaways:
  • Studies have shown that genetics play a significant role in your risk of developing a substance use disorder or addiction, with genetics accounting for 40-60% of a person’s likelihood of forming an addiction
  • When a person abuses substances regularly or in large amounts, the brain builds up a tolerance to the number of chemicals being produced, meaning the user can’t feel normal unless they continually abuse it. The way the brain changes is also the same for behavioral addictions, such as gambling disorder, where the dopamine hit from performing the act cannot be replicated by normal means
  • In 2019, 20.4 million people aged 12 or older (or 7.4 percent of this population) had an SUD in the past year, including 14.5 million who had an alcohol use disorder and 8.3 million who had an illicit drug use disorder
Human head silhouette made of various drugs and a wind-up key.

What is addiction?

Addiction is a chronic disease or dysfunction of the brain systems that control reward, memory, and motivation. This dysfunction affects how someone reacts to stimuli and causes the addict to crave it obsessively and the pleasure response it creates. Addiction is also characterized by the continuance to abuse a substance or behavior despite the negative consequences of doing so. The individual may also develop a tolerance for substance misuse, requiring a larger amount or more prolonged exposure to the substance to achieve its desired effect.

Someone experiencing addiction will often display the following symptoms:

  • Being unable to stay away from the substance or behavior
  • Having an increased need for the substance or behavior
  • Secretive behavior
  • Dismissive of how their behavior may be causing problems
  • Lack of emotion
  • Withdrawal from normal social activities
  • Physical neglect

Related: Addiction vs dependence

More often than not, addictions can lead to serious problems in health and day-to-day life. Those who are addicted are also likely to relapse when attempting to stop. This can mean addiction can cycle between mild and severe rapidly, though most will worsen significantly over prolonged exposure to the addictive substance or behavior.

Addiction can fundamentally change a person, impacting how they feel, act, and think. Those who do not get help for their addictions can end up isolating themselves from their loved ones.

Most of us will face the temptation to abuse substances or try risky behaviors at some point in our lives. While it may seem harmless, addictive tendencies can progress quickly, especially with substance abuse like drugs and alcohol. For instance, almost 1 in 4 Americans (23%) who try heroin will become addicted.

Common addiction forming substances

Almost all substances can lead to an addiction-forming when abused. This is due to the chemical imbalance they cause in the brain, which, if continually topped up by a substance, can lead to tolerance, dependence, and addiction. Some of the most common addiction-forming substances include:

Alcohol - Alcohol is a legal substance that is widely accepted and drunk around the world. While socially acceptable, alcohol can have a devastating impact on people's lives when abused.

Opioids - The nation is currently in the grip of an opioid epidemic. Illicit opioids such as fentanyl, as well as prescription medications, are leading to thousands of deaths each year

Marijuana - weed, bud, or cannabis has been a popular illicit narcotic for many years. While its effects are rarely life-threatening, addiction to marijuana can cause negative impacts to one's life which can lead to emotional turmoil.

Benzodiazepines - Often referred to as 'benzos', benzodiazepines are used to treat a wide range of medical conditions, from muscle spasms to insomnia. Dependence often forms quickly when benzos are abused.

Stimulants - Stimulants have become increasingly popular, both legally and illegally, as a form of substance abuse. Meth, cocaine, and crack have been some of the prime targets of the war on drugs, costing billions to the government as well as countless lives.

Sleeping Pills - Providing similar effects to benzodiazepines, sleeping aids or 'z drugs' can cause those who abuse them to become dependent on their sedative effects. Abusing sleeping pills can start as innocently as extending a dose or taking an extra pill of an evening.

Inhalants- inhalants such as aerosols, nitrates, and whippets are increasingly popular as a source of substance abuse amongst young people; owing largely to their ready availability in most homes.

Antidepressants - Not all antidepressants have addiction-forming qualities. In fact, most antidepressants take several months to have an effect on the brain's chemical balance. However, they can be extremely dangerous, especially when abused with other substances.

Causes of addiction

No one thing leads to addiction and it’s difficult to predict who is most susceptible.

It is often a complex mix of factors that lead someone to form an addiction, including some of the following:

  • Genetics
  • Environment
  • Socioeconomics
  • Personal trauma
  • Mental health factors

Genetics

Studies have shown that genetics play a significant role in your risk of developing a substance use disorder or addiction, with genetics accounting for 40-60% of a person’s likelihood of forming an addiction. Scientists have even found specific genes that play a role in increasing the risk of developing an addiction. This however, should not be confused with an addictive personality.

Environment

Living, working, or having grown up in an environment of increased exposure to drug or alcohol addiction increases the risk of developing a substance use disorder. A study by the National Association of Children of Alcoholics indicates that children raised by alcoholic parents are three times as likely to develop alcoholism.

Socioeconomics

Socioeconomic risk factors for developing a substance use disorder include low income, low levels of education, and prior use of alcohol in childhood or adolescence.

Personal trauma

People often abuse substances to cope with past mental or physical trauma, which can lead to addiction. Some people also become addicts if they abuse prescription medication used to treat chronic diseases and other illnesses. This is often true of people who have post traumatic stress disorder (PTSD) which is commonly found in veterans.

Mental health disorders

Adults and teens who suffer from mental health disorders, such as bipolar disorder or depression, are more likely to develop substance abuse addictions and or a behavioral addiction than the rest of the population. The presence of a mental health condition and a substance use problem is often referred to as a co-occurring disorder.

However, having risk factors does not mean addiction is unavoidable. Similarly, the absence of risk factors does not protect you entirely from developing an addiction. The areas above are some common factors found in many people who suffer from a form of addiction.

Addiction and the brain

Prolonged or excessive substance abuse can affect many parts of the body, but none more so than the brain. When a person consumes substances like drugs or alcohol, their brain becomes flooded with chemical transmitters, such as dopamine, that activate the brain’s pleasure and reward systems.

When a person abuses substances regularly or in large amounts, the brain builds up a tolerance to the number of chemicals being produced, meaning the user can’t feel normal unless they continually abuse it. The way the brain changes is also the same for behavioral addictions, such as gambling disorder, where the dopamine hit from performing the act cannot be replicated by normal means, such as spending time with friends or family.

Recognizing addiction

Understanding what addiction “looks like” is a complex and inexact task. Through television, film, and other media, we are often told that a person with a drug addiction has a particular look or lives a lifestyle that makes them distinct from the rest of society. This is often not the case as substance addiction affects everyone differently, and those who have begun to recognize a problem in themselves will often try to hide or mask it from loved ones.

People with severe addictions can often still manage to live a relatively normal lifestyle, such as high functioning alcoholics. This means that there is not always a clear indicator for when someone is suffering from an addiction. However, if you believe someone you care about has started to become secretive about their actions or has started to abuse a substance, you should seek help.

Warning signs of addiction

While it may not always be possible to spot addiction, there are some red flags to be mindful of if you suspect someone is abusing a substance. Always bear in mind that everyone is different, and these indicators may not be present in all people suffering from addiction. The following are some warning signs of addiction:

  • Being secretive about parts of personal life
  • Withdrawal from social contact
  • Mood swings and changes in behavior
  • Trouble upholding commitments or responsibilities
  • Issues at home, work, or in education
  • Absences without explanation
  • New social groups
  • Unstable finances
  • Staying up later than usual or sleeping in longer
  • Lapses in concentration or memory
  • Lack of motivation
  • Weight loss or changes in physical appearance

Some people may not be aware that they have an addiction, or have not attempted to stop abusing a substance long enough for withdrawal symptoms to kick in. This can make it hard for a person to admit or recognize they have a problem on their own. If you feel that someone you know is suffering from addiction, contact a treatment center to find out what support is available.

Addiction or dependence?

The term “dependence” is often used interchangeably with addiction when discussing substance abuse disorders. While they share some commonalities, there are major differences between the two that should be recognized.

A dependence presents itself when someone builds up a physical tolerance to a substance, meaning they may have withdrawal symptoms if they stop using the drug or substance. Dependency can usually be resolved by slowly weaning off the drug and changing behavior patterns.

Addiction, on the other hand, occurs when a person's brain chemistry has changed from prolonged or extensive substance abuse. Addiction causes uncontrollable cravings, which the user will strive to fulfill despite the negative impact on their life. Often, the only way to get over an addiction is through professional treatment.

Another term that is commonly used alongside addiction and dependence is "compulsion". Again, compulsion has its own definition and is used to describe a completely different set of behaviors.

Related: Drug addiction and dependence hotlines

Diagnosing an addiction

Substance abuse or addiction is diagnosed by a medical professional based on a variety of factors. These factors will, in most cases, be based on an assessment of criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5):

  • Hazardous use
  • Continued use of the substance despite adverse effects on social or interpersonal problems
  • Neglecting work, social or educational responsibilities in favor of substance use
  • Experiencing withdrawal symptoms when stopping use
  • Developing a tolerance
  • Using larger amounts of the substance than the user intended to
  • Repeated failed attempts to quit or control use
  • Excessive time spent using the substance or recovering from its effects
  • Social and recreational activities replaced by substance abuse
  • Cravings
  • Continuing to use the substance despite negative psychological or physical effects

These criteria are measured on a spectrum of mild, moderate, and severe substance use disorder. Meeting 1-2 criteria is defined as mild, 3-5 moderate, and 6+ severe.

Although self-assessment through identifying the warning signs of addiction is possible, it should always be diagnosed by a licensed professional.

Substance use disorder (SUD) statistics

All statistics are from the National Survey on Drug Use and Health, 2019.

  • In 2019, 20.4 million people aged 12 or older (or 7.4 percent of this population) had an SUD in the past year, including 14.5 million who had an alcohol use disorder and 8.3 million who had an illicit drug use disorder.
  • Among the 8.3 million people with an illicit drug use disorder in the past year, 4.8 million people had a marijuana use disorder, and 1.4 million people had a prescription pain reliever use disorder.
  • Among the 14.5 million people with a past-year alcohol use disorder, 12.1 million had an alcohol use disorder but not an illicit drug use disorder.
  • Among the 8.3 million people with a past year illicit drug use disorder, 5.9 million had an illicit drug use disorder but not an alcohol use disorder.
  • Among people with a past year SUD, 11.8 percent (or 2.4 million people) had both an alcohol use disorder and an illicit drug use disorder in the past year.

The controlled substances act

The Controlled Substances Act (CSA) is the law that regulates and classifies legal and illegal drugs in the USA. Drugs are categorized into different “schedules” according to the perceived danger they pose and the potential for addiction or dependence. The schedule is as follows:

According to the Drug Enforcement Agency (DEA), each class has distinguishing properties, such as its potential for abuse, dependence, and addiction.

The CSA is primarily used to distinguish drug offenses in criminal proceedings and help physicians when prescribing medications.

Treatment for addiction

No matter what type of addictive behavior you or a loved one may be suffering from, a treatment program or rehab recovery facility can help overcome it. Get in touch with a treatment center today to find out what options are available.

Options for addiction treatment and rehabilitation include:

options for addiction treatment include:

Was this page helpful?

Your feedback allows us to continually improve our information

Resources:

  1. NHS. (2019). Addiction: What Is it? NHS.
  2. The Role of Genes in Drug Addiction | Scholastic: Nida. (2006, October 16). .
  3. Molyneux, A. (2020, March 22). What Causes Addiction & What Leads to addiction? Delamere Rehab. Delamere.
  4. Prescott, C. A. (2002). Sex differences in the genetic risk for alcoholism. Alcohol Research & Health : The Journal of the National Institute on Alcohol Abuse and Alcoholism, 26(4), 264–273.
  5. 2019 National Survey of Drug Use and Health (NSDUH) Releases | CBHSQ Data. (2019). .
  6. 2019 NSDUH Annual National Report | CBHSQ Data. (2020, September 11). .
  7. Drug Enforcement Administration. (2020). Drugs of Abuse A DEA RESOURCE GUIDE / 2020 EDITION.

Activity History - Last updated: 02 December 2024, Published date:


Reviewer

Dr. Samantha Miller is a practicing NHS doctor based in Glasgow, UK, who regularly contributes as a medical reviewer for mental health and addiction.

Activity History - Medically Reviewed on 15 June 2021 and last checked on 02 December 2024

more on addiction

Withdrawal Symptoms

9 minutes read