Addiction And Your Brain

In 1997, Former Director of the National Institute on Drug Abuse, Dr. Alan Leshner, suggested that addiction be defined as a “chronic, relapsing brain disorder” and, therefore, be viewed as a brain disease.

Since then, an addiction is generally defined as a psychological and physical dependence on a substance that a person continues to use regardless of the resulting negative consequences.

However, there is still much debate surrounding the criteria and scale that should be used to rate substances on their addictive properties and addiction risk, as factors such as the severity of withdrawal symptoms and physical and cognitive side effects can all play a part.

A 2020 study from the Annual Review of Psychology journal thinks they have the answer. It suggests that we focus on the brain when looking for addictive properties, specifically how the drugs affect dopamine levels.

Rise In Dopamine Levels

Most substances affect the brain, albeit in varying ways and levels of severity. Almost all addictive drugs impact the brain’s reward system and cause some disruption to the normal creation, flow, and release of dopamine, the neurotransmitter responsible for feelings of pleasure.

Initially, ingesting these substances results in normal dopamine function, resulting in pleasurable feelings; however, the study found that habitual use resulted in decreased expression (of varying levels) of dopamine receptors, leading to adverse feelings and withdrawal symptoms. In turn, this makes an individual increase use to achieve the short burst of dopamine and feelings of euphoria that become shorter and shorter as addiction develops.

Therefore, this article defines the most addictive substances as substances that greatly affect dopamine levels and are most likely to cause addiction.

1. Cocaine

The study found Cocaine to be the most addictive substance based on its powerful affect on the brain. Cocaine is a potent stimulant that is characterized by bursts of extreme happiness, focus, energy, and alertness, but it can also cause irritability and paranoia when misused.

In the brain, Cocaine elevates dopamine levels, resulting in a euphoric feeling that is distinctive from the high and pleasurable feelings produced by other drugs. Due to this extreme high, people who use Cocaine are particularly aware of the adverse psychological side-effects of Cocaine withdrawal and abstinence, such as depression and fatigue, leading them to use the drug at an increased frequency.

In the US, 1.4 million people over the age of 12 reported having a Cocaine use disorder.

2. Methamphetamine

Methamphetamine is a habit-forming stimulant that results in increased alertness, talkativeness, and hyperactivity. Adverse side effects include irregular heartbeat, agitation, increased blood pressure, and aggressive behavior.

Methamphetamine causes rapid dopamine release, significantly increasing the amount of dopamine in the brain during use. This rush of dopamine leads to increased use, as people who use the drug try to recreate and repeat the experience, leading to addiction.

In the US, 1.6 million people over the age of 12 reported having a Methamphetamine use disorder.

3. Opioids

Opioids are potent drugs most commonly used for pain relief. Misuse of Opioids (particularly Heroin and Fentanyl) is extremely dangerous, with approximately 107,000 drug overdose deaths in 2021 involving these drugs.

Opioids differ from other drugs in how they affect dopamine levels, as they specifically attach to the GABA neurotransmitter, which controls the brain’s reward and pleasure pathway. Once the Opioids slow down the GABA neurons, dopamine floods the brain’s pleasure circuits, resulting in a wave of pleasure and pain relief. These effects reinforce the idea in the brain that taking Opioids is a rewarding experience, leading to increased use and addiction.

In the US, 2.7 million people over the age of 12 qualify as having an Opioid use disorder.

4. Alcohol

Alcohol is a depressant and is the most widely used substance on this list, with 138.522 million Americans over the age of 12 reporting regular alcohol use.

Generally, alcohol minorly elevates dopamine levels but can cause dopamine spikes at low doses and during the early stages of intoxication. Habitual alcohol use can cause persistent cravings and behavioral distress during alcohol withdrawal periods, leading to a cycle of use to try and numb these feelings.

In the US, 28.3 million people over the age of 12 qualify as having an alcohol use disorder.

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5. Nicotine

Nicotine is a stimulant that elevates dopamine levels and causes burst firing of dopamine neurons. It is fast-acting and reaches the brain within seconds, leading to an immediate release of dopamine. Though it does not result in episodes of energy and alertness like other stimulants on this list, nicotine still activates the brain’s reward system and is strongly linked to behavioral dependence.

In the US, 23.6 million people over the age of 12 experience nicotine dependence.

Break Free Of Addiction

If you struggle with an addiction to any of the most addictive substances listed here, know that the weight of addiction doesn’t have to hold you down any longer. Help is available.

Treatment can help you safely overcome addiction and help you achieve sustained sobriety. Call now to talk with a treatment provider who can provide more information on your treatment options.

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Jessica Sherer

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  • Jessica Sherer earned her B.A. in English from Ashford University and has over eight years of copyediting experience in healthcare education. Dedicated to providing clear and useful information, she hopes her work will help to support those affected by addiction.

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