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How Addiction Affects the Brain

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Medically Reviewed By: Diana Vo, LMFT

August 25, 2022 (Originally Published)

May 17, 2023 (Last Updated)

Table of Contents

Addiction affects the brain in many different ways, and understanding the effects of drugs on the brain can help you better gauge the risks you’re taking when abusing substances. 

Whether you’re using alcohol, opioids, stimulants, sedatives, or nicotine, these compounds enter your brain and your bloodstream. As soon as this substance has entered your brain, you can lose control of your impulses, and you can start craving more of the substance.

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When substance abuse spirals into full-blown addiction, your brain craves the rewarding effects delivered by the substance. This occurs due to the way the brain’s reward system is intensely stimulated by the substance in question. 

The response to this craving in many people is the continued use of the substance. 

The long-term effects of addiction on the brain include permanent brain damage. Sustained substance abuse can even be fatal.

These problems can obviously be disastrous, that said, there are addiction treatment programs, like a Malibu rehab, and sober living homes in place to help you conquer these addiction problems.

What Effects do Drugs Have on the Brain

Different drugs impact the brain in different ways, but most substances hijack the brain’s reward system. 

All addictive drugs increase the release of dopamine in the brain. Over time and with sustained substance abuse, the brain stops producing normal levels of dopamine, leading you to become reliant on the substance to feel normal. 

Drugs also serve to alter brain circuitry, causing you to associate certain people, places, and things with the favorable, euphoric outcome of substance abuse. 

Beyond this, changes to the executive center of the brain – the area responsible for motivation and rationalization –  can also lead to a strong desire to abuse substances regardless of the consequences.

Psychological Effects of Drugs on the Brain

Substance use disorder commonly co-occurs with mental health disorders like depression, anxiety, PTSD, and bipolar disorder. According to research, 25% of people with serious mental health conditions also have substance use disorder.

 Using drugs during adolescence can increase your risk of developing both substance use disorders and mental health disorders in adulthood according to the same data. 

Unfortunately, these two conditions feed into each other. According to NAMI (the National Alliance on Mental Illness), many people attempt to self-medicate the symptoms of mental health disorders. This may provide some short-term relief, but it ultimately inflames rather than soothes these symptoms, while often creating new side effects for you to deal with.

Physical Effects of Drugs on the Brain

Different drugs trigger different long-term effects on the brain. Despite the unique effects caused by various drugs, though, sustained substance abuse causes some universal physical changes to the brain. 

When you ingest addictive substances they interact with your brain’s limbic system resulting in the release of powerful feel-good emotions. When you do something pleasurable, your brain rewards you. This desire to recreate a euphoric feeling is the primary underlying driver for most substance abuse. As changes occur to the brain’s structure and functioning over time, you’ll require the substance just to feel normal. 

Alcohol can bring about a variety of short-term effects related to the brain, including memory lapses and impaired reaction times. Over time, chronic alcohol abuse can cause brain shrinkage, with women especially vulnerable to these effects.

Effects of Psychoactive Drugs on the Brain

How about the effects of psychotropic drugs on the brain, then? 

Well, mind-altering drugs may speed up or slow down the CNS (central nervous system), depending on whether they are stimulants or sedatives. 

Psychoactive drugs can also impact the following functions: 

  • Respiration
  • Heart rate
  • Blood pressure
  • Body temperature

Psychoactive drugs also impact the following chemical messengers in the brain known as neurotransmitters: 

  • Dopamine: This chemical governs mood, enhances pleasure, and is associated with reward, and reinforcing behaviors, as well as attention and motivation.
  • GABA (gamma-aminobutyric acid): GABA works as a tranquilizer, reducing your body’s stress response while at the same time also reducing anxiety levels and slowing down certain functions of the CNS.
  • Serotonin: This brain chemical helps regulate emotions and stabilize moods.
  • Norepinephrine: Much like adrenaline, norepinephrine is a stress hormone responsible for speeding up your CNS when you encounter the fight-or-flight response. This chemical also boosts energy levels and sharpens your attention and focus.

 Marijuana is the most commonly used drug in the United States, with NIDA reporting that use is especially widespread among young adults and adolescents. 

THC (delta-9-tetrahydrocannabinol) is the psychoactive component of marijuana, and this is responsible for the relaxing and mellow high induced by the drug. This chemical binds with your brain’s natural cannabinoid receptors, with regions of the brain with heavy saturations of receptors more heavily impacted. 

One of these areas of the brain is the hippocampus, an area responsible for short-term memory. The basal ganglia and cerebellum are also affected, with these areas controlling involuntary muscle movements and coordination. 

The sustained abuse of marijuana can lead to impairments in the following areas: 

  • Distorted time and sensory perception
  • Difficulties thinking clearly
  • Inability to solve problems
  • Altered moods
  • Memory issues

NIDA warns that the effects of drugs on the teenage brain are most acutely felt, with the long-term brain effects of marijuana use in those who start using the drug before the brain is fully developed being the most prevalent. The unfortunate by-product of early-onset marijuana use can be a loss of IQ points not recoverable, even after a period of abstinence.

It’s not just illicit drugs that affect the brain, though.

Effects of Prescription Drugs on the Brain

When opioid use descends into dependence and addiction, the following changes to the brain can occur: 

  • Changes to white matter, potentially leading to violence and aggression
  • Changes in the functioning of interconnectivity between brain regions, possibly triggering impaired cognitive processing
  • Structural changes to the brain
  • Loss of volume in the amygdala

Opioid overdose can lead to brain injuries related to hypoxia. These can include: 

  • Confusion
  • Disorientation
  • Memory problems
  • Behavioral changes
  • Impaired cognitive functioning
  • Decreased motor skills
  • Impaired reaction time
  • Incontinence
  • Paralysis

The long-term use of benzodiazepines, on the other hand, is linked to cognitive decline.

Overcoming Drug Abuse at Renaissance Recovery

If you have been abusing any kind of substance, whether alcohol, prescription opioids or benzos, or illicit drugs, research shows intensive outpatient programs (IOPs) are typically just as effective as residential rehab for treating most addictions. 

Here at Renaissance Recovery, we have a variety of personalized outpatient treatment programs to help you combat your substance use disorder, as well as any co-occurring mental health disorders. 

Through a combination of medication-assisted treatment and psychotherapy like CBT or DBT, you’ll explore the root cause of your addiction, while negotiating detox and withdrawal as seamlessly as possible. You’ll also have counseling – both individual and group – as well as holistic therapies, experiential adventure therapies, and vocational development programs. 

All you need is the commitment to sobriety and the willingness to reach out to admissions right now at 866.330.9449. We’ll guide you every step of the way through your ongoing recovery journey.



At Renaissance Recovery our goal is to provide evidence-based treatment to as many individuals as possible. Give us a call today to verify your insurance coverage or to learn more about paying for addiction treatment.

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Joseph Gilmore has been in the addiction industry for three years with experience working for facilities all across the country. Connect with Joe on LinkedIn.

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