For many people who struggle with drug abuse, there is confusion about whether or not they have developed addiction to a substance.
 
These individuals may question exactly what defines the difference between casual substance use, substance abuse, and the uncontrolled dependence that leads to addiction. In fact, many people don’t know exactly what addiction is, let alone how it happens.  

When trying to understand addiction, it helps to know how drugs work in the brain and what happens as an individual chronically abuses illicit, prescription, or other substances for recreation or even as medical treatment. The path from casual substance use to addiction can be basically understood, and it can help those who may be dealing with substance abuse to identify whether or not their drug or alcohol use has crossed the line into addiction.

What Is Addiction?

Substance use disorders involve a spectrum of behaviors and symptoms that indicate an individual has lost control of drug or alcohol use. While not all of these disorders are strictly defined as addiction, the word is often used as a catchall synonym for substance abuse. Nevertheless, addiction is only one type of substance use disorder, found on the more severe end of the spectrum. 

As defined by the American Society of Addiction Medicine, addiction is a chronic brain disorder characterized by dysfunction in the pleasure, reward, memory, and motivation pathways of the brain. While many believe that addiction is based only on the euphoria or pleasure aspect of substance use, it also has a foundation in memory and motivation dysfunctions, which contribute to the poor decision-making and judgment capabilities that lead to continued substance use. 

Another way to describe addiction is simply as the inability to control use of and dependence on an illicit or other substance that requires continued use of the substance for the individual to function properly. However, this raises a question about the difference between a person who is addicted to a drug and a person who is dependent on a drug for health reasons. As defined by the National Institute on Drug Abuse (NIDA), the difference here is that a person who is addicted cannot control the amount or frequency of the drug abuse even in the face of other consequences. In contrast, a person who is dependent on a drug for health reasons could stop if desired.
 

Substance Abuse and the Brain

Further understanding of these differences comes through knowledge of how addictive substances act on the brain. As described by the University of Utah’s Genetic Science Learning Center, the process by which drugs affect the chemical pathways of pleasure, reward, memory, and motivation has mainly to do with the following steps: 

  1. The drug interacts with neurons – brain cells – to release certain chemicals. This happens chiefly though the dopamine system; however, other neurochemicals, such as epinephrine and GABA, are implicated as well. This results in a pleasure reaction that alters these chemical systems and their behavior. 
  2. Brain chemistry activity changes to counteract the use of the substance. This contributes to tolerance, which is one of the steps in the path to addiction and explained further below. 
  3. Some neurological pathways are physically altered to help the brain adapt to the drug use, which results in the behaviors becoming reflexive. 
  4. Long-term to permanent brain changes result. These permanent changes account for the fact that, even long after treatment, individuals who have struggled with drug abuse may still have cravings. 
  • Learn More

    These steps correlate fairly directly with the development of addiction, which is further described below. As a result, it can be said that addiction is specifically related to the effect that the drugs have on the physical systems in the brain.

    Factors That Contribute to Addiction Risk

    Use of drugs isn’t the only contributing factor to the risk of developing addiction. Mayo Clinic describes other factors that are involved as well, which can make it more likely that a person will develop addiction. These include:

    • A personal or family history of drug abuse (sometimes considered to be a genetic predisposition)
    • Gender, as men are more likely than women to have problems with drugs, but women tend to develop addiction faster than men do
    • A personal or family history of other mental health issues; sometimes drug abuse results from trying to self-medicate for difficult mental issues like depression, anxiety, or PTSD
    • Friends who abuse or are addicted to drugs and invoke peer pressure or encourage drug use
    • Family or friends who are permissive or lackadaisical about drug or alcohol use
    • A history of abuse or neglect

    Individuals who are using drugs and also display one or more of these other factors are more likely to develop abuse or addiction problems. In particular, genetics can contribute to how susceptible the brain is to the changes that lead to addiction; however, this is not the most important factor in whether addiction will develop. Most often, addiction develops as the result of many of these factors coming together.

The Path to Addiction

As described by the Harvard Mental Health Letter, addiction results from fundamental changes in brain structure and function that follows regular substance abuse. This change in the brain can be described as a process that involves the following steps:

  • Pleasure
  • Learning
  • Tolerance
  • Compulsion

First, the individual starts using drugs to experience the pleasure of the high, which stems from the dopamine system as described above. While it would seem that this is enough to drive a person to keep wanting to use the drug, there is more to it than that. The fact is that chemicals implicated in learning and motivation are also affected by addictive drugs, including the neurotransmitter glutamate.

Once the person begins abusing the substance regularly, tolerance can develop. This is a process by which the brain becomes used to the amounts of the drug that the person has been using, and the pleasure response begins to get weaker, prompting the person to use more of the drug to get the same level of response. Once tolerance has developed and the individual begins using the drug more often or in higher amounts, the process spirals, causing further changes in the brain.

By the time the individual has begun increasing intake to manage tolerance, compulsion to use the substance is also occurring, as explained by an article from Current Directions in Psychological Science. This is the final step in the development of addiction, because not only does the person need to keep taking the drug to feel good, but control over the amount or frequency of drug use has been lost, replaced by a reflexive or conditional response to stimuli that involves resorting to drug use.

Consequences of Addiction

The consequences of this process are also the symptoms and signs that are used to diagnose addiction or substance use disorders. According to the Diagnostic and Statistical Manual of Mental Disorders, these include:

  • Inability to control substance use
  • Cravings for the substance
  • Increased focus on getting, using, and recovering from substance abuse
  • Problems in relationships based on the substance use
  • Trouble keeping up with responsibilities because of substance use
  • Changing social activities or peer circle because of substance use
  • Continued use despite mental, physical, or social consequences of use

Addiction thoroughly disrupts an individual’s life and social network, even if the person is not aware of the issues. Ultimately, addiction can lead to severe health consequences as well.

Recovery from Addiction

Because addiction is a chronic mental health disorder, it can be treated. Like many chronic physical illnesses, the process of treating addiction is highly individual and depends on the person’s specific risk factors, the drug of abuse, and other factors that require treatment to be personalized. Through research-based treatment programs that keep up with the latest studies and treatments for substance abuse, it is possible for each individual to find care that is right for them.

A combination of medical and psychosocial treatments can help those who are struggling with substance abuse not only to stop using the drug of addiction, but also to learn how to control cravings that would otherwise lead to continued substance abuse. Through these therapies, the individual can gain control of life again and learn how to move forward into a sober, productive future.