A number of scientific studies have revealed the complex workings of our brain’s motivation and reward center and how neurotransmitters, often referred to as the brain’s “feel-good chemicals,” are released when we desire something or experience pleasure.
Our brains produce numerous natural neurotransmitters that play critical roles in our health and how we feel. The brain also changes its production of these neurotransmitters in response to certain substances or stimuli, and this is why many experts now recognize the role neurotransmitters play in addiction. They explain that we become addicted as chemically induced alterations in neurotransmitter levels confuse the brain’s pleasure and reward mechanisms, driving addiction and, ultimately, challenging recovery.
How Neurotransmitters Affect Health and Happiness
Dopamine is a neurotransmitter that plays a key role in mood, motivation and drive, desire, satiety and pleasure. This has earned dopamine the distinction of being labeled the feel-good chemical, but other neurotransmitters can also have a pleasure/reward effect.
Endorphins are considered “pleasure chemicals” because a boost in endorphin levels contributes to making us feel better when we exercise, have sex or fall in love, and reduces our perception of pain. Serotonin plays a role in relaxation, sleep and appetite. Gamma-aminobutyric acid, or GABA, has a calming effect and, thus, also relaxes us. Norepinephrine is another neurotransmitter that is released when we fall in love, and also plays a role in concentration, alertness and energy, particularly related to how we respond to stressful situations. Acetylcholine’s role is to help us remember things and process information. Glutamate has many different roles, but is particularly important in regulating brain function — its neurotransmitter system supports cognition, learning and memory.
How Neurotransmitters Drive Addiction
The mechanism by which our brain’s reward center regulates neurotransmitters undergoes a change when we drink alcohol or take certain drugs, and this is how these chemicals can play a role in addiction. In most people, there is a temporary shift in neurotransmitter levels after we have a drink or other substance, but those levels soon shift back to normal after we metabolize it. In other people, the brain’s response to a change or super-charged surge of neurotransmitters brought on by alcohol or other drugs catalyzes a response from the brain’s reward center that says, “I have to have some more of that!” This same response can occur with addictive behaviors like gambling, where a person feels a rush of excitement with the anticipation of winning (even when they don’t win).
What Happens When Alcohol or Other Drugs Enter the Scene?
For people who have a predisposition for addiction, the circuitry in the brain’s reward center changes in response to certain substances or stimuli, triggering a seek-and-reward mechanism — in other words, by becoming addicted. Over time and with repeated exposure, the person begins to crave more of the substance or activity that produces the positive feelings or relief from negative feelings.
But the brain is just one part of the story. Addiction has many contributing factors — from genetics (addiction can run in families) to socioeconomic status, one’s environment and any pre-existing mental health disorders. (For example, we know there is a high prevalence of depression, trauma and other problems among drug users.) All of these elements play a role in how we respond to alterations in neurotransmitters levels.
Neurotransmitters Gone Haywire: How Different Substances Affect Us
Let us assume that the stage is set for addiction, likely through a combination of brain functions and other factors that motivate a person to take, continue taking, and become dependent upon a drink or drug. Here’s how different substances affect the brain and its neurotransmitters:
- Alcohol is thought to affect several neurotransmitter systems, including those for GABA, glutamate, serotonin, dopamine and endorphins, resulting in either a sedative or an excitatory effect, depending on extent of use.
- Benzodiazepines (Valium, Xanax, Ativan, Rivotril) impact GABA, resulting in a sedative effect.
- Opioids (painkillers like Vicodin, Percocet, OxyContin, morphine and the street version heroin) impact endorphins and other naturally occurring opioids in our system, modulating our reactions to pain and altering functions like mood control, hunger and thirst.
- Amphetamines (Adderall, Ritalin, Dexedrine) are often used to combat fatigue, impact dopamine and some glutamate receptors, resulting in increased energy and feelings of excitability.
- Cocaine boosts dopamine levels, producing cravings and dependency on the drug. It also affects serotonin, leading to feelings of confidence, and norepinephrine, increasing energy.
- Ecstasy/Molly (MDMA) is a psychostimulant that simultaneously works as a stimulant and a hallucinogen. It affects norepinephrine, dopamine and serotonin, leading to a combined effect of increased energy, euphoria and lowered inhibitions in relating to other people.
- Marijuana (cannabis) affects both dopamine and the neurotransmitter anandamide, which is involved in regulating mood, memory, appetite, pain, cognition and emotions.The resulting sensations include mild euphoria, relaxation and amplified auditory and visual perceptions.
How Neurotransmitters Impact Detox and Recovery
Addiction eventually leads to a physiological shift in the signaling processes of neurotransmitters — essentially, addiction changes how our brains are wired.
This change in brain mechanisms helps explain how addiction takes hold and why it can be so painfully difficult to quit alcohol or other drugs. Through detox and rehab, we can reverse the damage to the brain’s wiring system and restore normal neurotransmitter signaling processes. However, it takes time for our brains, bodies and behaviors to adjust and unlearn the mess that substance abuse has created.
During detox, withdrawal from drugs and alcohol results in a range of emotional, behavioral and cognitive challenges. The damage addiction has done to neural pathways involved in reward, pain relief, stress management, sleep, arousal, learning and memory can have effects that last long after quitting the substance of abuse.
A Damaged Neurotransmitter System Needs Time to Heal
Although the most acute symptoms of withdrawal will typically pass in a couple of weeks, addiction has long-term psychological and physical consequences. People in rehab can experience cycling or worsening symptoms over the next four to eight weeks as their brains and bodies undergo shifts in neurotransmitter wiring. This process can be extremely difficult.
Among the challenges addicts in recovery experience is an increased sensitivity and reactivity to stress and addiction triggers or cues — the people, places and things that remind them of using, causing them to crave their substance of abuse. Their emotional reactivity can manifest as heightened anxiety, confusion and fear. All of these symptoms can be correlated to the internal shift that is occurring in the brain’s reward center and the glutamate-regulated neurotransmitter system, as many drugs of abuse block glutamate. In response, the body increases glutamate production, even after the drug has been detoxed out of the system.
In early recovery, addicts tend to experience problems with impulsivity, challenges with deferred rewards vs. instant gratification, and difficulty learning new coping mechanisms. People who have been addicted to opioids (i.e., pain medications and heroin) may have a lower tolerance for both physical and emotional pain and discomfort, making the recovery process even more challenging.
During a 30- or 60-day rehab treatment program, addicts get professional support for withdrawal symptoms, assistance in learning how to use new coping tools, and encouragement to eat well, sleep more, exercise and find constructive ways to reduce stress — practices that boost the natural production of neurotransmitters and help ease them through recovery. Additionally, engaging in spiritual activities has been shown to increase levels of dopamine and serotonin, which may explain the success of some 12-step programs that emphasize the spiritual aspect of the recovery journey.
Neurotransmitter Adjustment Period and a 90-Day Treatment Model
Despite the integration of neurotransmitter-boosting practices and activities in rehab and recovery programs, addicts’ brains and bodies need ample time to unlearn addictive behaviors and adjust to the physiological changes that occur with abstinence. This might explain why many addicts tend to relapse around the eight-week stage of recovery — the peak in the neurotransmitter system’s dramatic readjustment period.
Many addiction specialists recommend 90-day addiction treatment programs as the gold standard, depending on an individual’s drug of abuse, the presence of any co-occurring disorders, and their response to treatment. The DSM-5 recommends 90 days for achieving “early remission,” and studies show that longer programs tend to have better outcomes in helping addicts achieve lasting sobriety. Perhaps this is because a 90-day program provides an individual with clinical support as they push through that difficult eight-week phase and beyond, allowing the brain and its reward system more time to heal from the physiological effects of addiction as well as addictive behaviors.
The Mysterious Motivational Functions of Mesolimbic Dopamine. JD Salamone, M Correa. Neuron, 2012.
Endorphins and exercise. VJ Harber, JR Sutton. Sports Medicine, 1984.
Serotonin: Facts, What Does Serotonin Do? J McIntosh. Medical News Today, 2016.
The Brain from Top to Bottom. GABA, Anxiety Neurotransmitters, XXX McGill University, Canadian Institute of Neurosciences, Mental Health and Addiction, 2016.
Norepinephrine. Rice University, Creative Commons. 2016
What falling in love does to your heart and brain. P Mumby, M Lynn. Loyola Sexual Wellness Clinic and professor, Department of Psychiatry & Behavioral Neurosciences, Loyola University Chicago Stritch School of Medicine (SSOM). Loyola University Health System, 2014.
Chapter 11: Acetylcholine Neurotransmission. JC Waymire, Department of Neurobiology and Anatomy, The UT Medical School at Houston, Neuroscience Online, 2017.
Glutamate as a Neurotransmitter – An Overview. NC Danbolt. The Neurotransporter Group: Dynamics of extracellular transmitter amino acids. Centre for Molecular Biology and Neuroscience, 2017.
Alcohol and Neurotransmitter Interactions. CF Valenzuela. Department of Pharmacology,
University of Colorado. Health Sciences Center, Denver, Colorado, 1997.
The Effects of Alcohol on the Brain. GF Koob. The Scripps Research Institute, 2002.