How Does Heroin Affect the Brain?

How Heroin Affects the Brain

In 2015, more than 52,000 Americans died of drug overdoses, according to the Centers for Disease Control and Prevention. That is an average of one death every ten minutes. Approximately 33,000 of these fatal overdoses—nearly two-thirds of them—were from opioids, including prescription painkillers and heroin.  While we may know some information about the heroin epidemic, it’s also important to know why this drug is so addictive. So, if you’ve ever wondered how heroin affects the brain, this may be helpful. 

What is Heroin and Where Does It Come From?

Heroin is an opioid drug made from morphine, a natural substance taken from the seed pod of the various opium poppy plants grown in Southeast and Southwest Asia, Mexico, and Colombia. Heroin can be a white or brown powder, or a black sticky substance known as black tar heroin. Other common names for heroin include big H, horse, hell dust, and smack. 

How Heroin Affects the Brain and it’s Opioid Receptors

Heroin enters the brain rapidly and binds to opioid receptors on cells located in many areas, especially those involved in feelings of pain and pleasure and in controlling heart rate, sleeping, and breathing. Opioids can activate receptors because their chemical structure mimics that of a natural neurotransmitter. This similarity in structure “fools” receptors and allows the drugs to lock onto and activate the nerve cells. Although these drugs mimic brain chemicals, they don’t activate nerve cells in the same way as a natural neurotransmitter, and they lead to abnormal messages being transmitted through the network.

Opioids target the brain’s reward system by flooding the circuit with dopamine. Dopamine is a neurotransmitter present in regions of the brain that regulate movement, emotion, cognition, motivation, and feelings of pleasure. The over-stimulation of this system, which rewards our natural behaviors, produces the euphoric effects sought by people who misuse drugs and teaches them to repeat the behavior. 

The Effects of Heroin and the High Potential for Abuse and Addiction

People who use heroin report feeling a “rush” (a surge of pleasure, or euphoria). However, there are other common effects, including: dry mouth, warm flushing of the skin, heavy feeling in the arms and legs, nausea and vomiting, severe itching, clouded mental functioning, going “on the nod”, a back-and-forth state of being conscious and semiconscious. 

People who use heroin over the long term may develop insomnia, collapsed veins for people who inject the drug, damaged tissue inside the nose people who sniff or snort it, infection of the heart lining and valves, abscesses (swollen tissue filled with pus), constipation and stomach cramping, liver and kidney disease, lung complications, including pneumonia, mental disorders such as depression and antisocial personality disorder, sexual dysfunction for men, irregular menstrual cycles for women.

Heroin binds to and activates specific receptors in the brain called mu-opioid receptors (MORs). Our bodies contain naturally occurring chemicals called neurotransmitters that bind to these receptors throughout the brain and body to regulate pain, hormone release, and feelings of well-being. When MORs are activated in the reward center of the brain, they stimulate the release of the neurotransmitter dopamine, causing a sensation of pleasure. The consequences of activating opioid receptors with externally administered opioids such as heroin (versus naturally occurring chemicals within our bodies) depend on a variety of factors: how much is used, where in the brain or body it binds, how strongly it binds and for how long, how quickly it gets there, and what happens afterward. 

Heroin and the Brain

How Does Heroin Use Rewire the Brain and Lead to Addiction?

Among the many problems of using heroin to get high is that the effect diminishes with every exposure to the drug. The more a person takes, the more the body gets used to it – a process known as tolerance 

The National Institute on Drug Abuse explains that as the brain adapts to what the heroin is doing to it, it responds less and less if the same amount of heroin is used. This usually compels users to increase their doses, desperate to experience the same sensation that got them hooked in the first place. It may take a number of hits of a higher dose to feel that; but by that point, the tolerance level has already increased, so users simply take more heroin. In the process, they become increasingly dependent on heroin for pleasure and even for the anticipation of pleasure. Nothing else in life matches up to what the heroin does, even as more and more heroin is needed to recapture the feeling of that first dose. 

Over time, users withdraw from social activities and obligations, partly because the tranquilizing effects of the heroin preclude activity and involvement in anything, and also because life begins to revolve around seeking out and being in the narcotic haze of a heroin high. 

Get Treatment for Heroin Addiction

A range of treatments including medicines and behavioral therapies are effective in helping people stop heroin use. It’s important to match the best treatment approach to meet the particular needs of each individual patient. 

Medicines include buprenorphine and methadone. They work by binding to the same opioid receptors in the brain as heroin, but more weakly, reducing cravings and withdrawal symptoms. Another treatment is naltrexone, which blocks opioid receptors and prevents opioid drugs from having an effect. 

Behavioral therapies for heroin addiction include methods called cognitive-behavioral therapy and contingency management. Cognitive-behavioral therapy helps modify the patient’s drug-use expectations and behaviors, and helps effectively manage triggers and stress. Contingency management provides motivational incentives such as vouchers or small cash rewards for positive behaviors such as staying drug-free. These behavioral treatment approaches are especially effective when used along with medicines. Our brains are wired to ensure that we will repeat life-sustaining activities by associating those activities with pleasure or reward.  

Whenever this reward circuit is activated, the brain notes that something important is happening that needs to be remembered, and teaches us to do it again and again, without thinking about it. Because drugs of abuse stimulate the same circuit, we learn to abuse drugs in the same way.

If you or someone you love is addicted to heroin, now is the time to seek professional help. The admissions professionals at Get Treatment will help you find a drug treatment center that provides individualized care and comprehensive treatment programs for opioid addiction. Call 855-638-9268 today for more information about how to get started.


Erica Loret de Mola

Erica Loret de Mola is a communications major who has been writing about addiction treatment for approximately three years. As content manager and editor in chief of Get Treatment, she strives to provide the most accurate and current information available to our clients.


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