Biology of Substance Use Disorder

There is much more to addiction than the physical act of engaging with substances. Learning more about substance use disorders (SUDs) and the biological elements behind substance abuse can help individuals understand how addiction develops and why it affects some people more than others.

SUD can disrupt normal brain function and may be negatively affecting an individual's life. Therefore, having as much accurate, detailed information as possible can help guide individuals toward a healthier lifestyle free from the affliction of substance abuse. Whether a person is dealing with addiction themself or they have a loved one who needs help, the first step toward healing and destigmatizing SUD is learning about the biological processes behind addiction.

Why Some People Believe Substance Use Disorders Are a Choice

Many scientists and researchers have long worked together to learn more about substance use disorders and ways to improve treatment options in the addiction recovery field. One of the most important scientific findings surrounding addiction is that it is not something that one can stop simply through willpower.

Learning about the basics of substance abuse can help people understand the importance of treatment and why many individuals struggle with the ability to control their impulses regarding drug and alcohol use. Many people believe that addiction and continued use of a harmful substance despite consequences is a choice that can be stopped at any time. These people often view addiction and relapse as a moral failing or a deliberate choice.

The National Institutes of Health (NIH) shares that substances like drugs and alcohol change brain structures, causing damage to people's usual pleasure and reward systems, as well as decision and impulse control capabilities. This means it is not necessarily up to the individual’s choice to quit or stop using substances because their brain has been damaged. It takes time and specialized care to undo this damage.

Dopamine and the Brain

Every substance affects the brain differently. All addictive substances produce high levels of the neurotransmitter dopamine in a region of the brain called the basal ganglia; this increase in dopamine causes the pleasurable feelings of being high.

Neurotransmitters are chemicals that transmit messages between nerve cells. The brain contains a “reward system." The ability to learn is based on what the brain perceives as rewards. As a person continues to use drugs and alcohol, these parts of the brain begin to adapt. When a person continues to use drugs or alcohol, the brain becomes less sensitive to dopamine, leading to a reduction in the “euphoria” felt after using substances.

Tolerance Paves the Way to Substance Use Disorder

When a person no longer feels euphoric effects after using substances, this is known as tolerance. Tolerance reflects how the brain maintains balance and adjusts to the frequent presence of drugs or alcohol. As a result of tolerance, many people increase the number of drugs or alcohol they use in an attempt to achieve the “high” they are used to.

Repeated substance use trains the brain to associate drugs and alcohol with other cues in the person’s life, such as friends they drink or do drugs with, places where they use substances, and paraphernalia that accompany their substance use. As these cues become increasingly associated with the substance, the person may find it more and more challenging not to use drugs or alcohol.

The Extended Amygdala and Withdrawal

Changes to the extended amygdala make it extremely challenging for someone with a severe SUD to stop using drugs or alcohol. The extended amygdala controls one's responses to stress. While increased dopamine in the basal ganglia causes a need to seek rewards, an increase in stress neurotransmitters in the extended amygdala pushes the brain to “escape” unpleasant situations. Together, these two parts of the brain control the spontaneous drive to seek pleasure and avoid pain.

When someone is struggling with SUD, the balance between these two parts of the brain decreases. As people continue using substances, they begin to feel emotional or physical distress when they do not take the substance or take less than they are used to. The emotional and physical symptoms that occur are known as withdrawal.

Withdrawal symptoms are challenging to get through, which motivates people with SUD to escape them. As a result, people who abuse drugs and alcohol begin to associate substance use with relief.

Once an individual gets stuck in this cycle, they are no longer using drugs and alcohol to get high. Instead, the need to use substances comes from a need to avoid feeling unpleasant emotional and physical symptoms. As a result, other priorities, including work, family, and hobbies that once produced pleasure, no longer compare to using drugs and alcohol.

Substance use disorder (SUD) is a disease that significantly affects the brain. Despite the belief that SUD is a moral failing, changes in the brain make it impossible to quit using drugs or alcohol through willpower alone. If you or a loved one is struggling with SUD, NorthStar Transitions is here to help. Our treatment facility has highly skilled and trained clinical staff who constantly seek to improve and enhance our services to support our clients. We can help you through every step of treatment; from managing withdrawal symptoms in detox to avoiding relapse after graduating from an inpatient program. The NorthStar difference is clinical excellence, evidence-based therapeutic modalities, personalized treatment plans, and our location in the serene and majestic setting of Boulder, Colorado. Learn more about our services and how we can help you by calling us today at (303) 558-6400.

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