What happens when heroin hijacks the brain?
Heroin molecules fit into brain cells in such a way as to induce euphoria and suppress functions as basic and instinctive as breathing.
The drug, a derivative of the opium poppy — and its natural and synthetic relatives — mimics brain chemicals and fits into receptors on the surface of neurons that are designed for the natural chemicals involved in pleasure and reward responses.
Initially, opioid abuse brings relaxation and generates levels of the brain chemical dopamine significantly higher than that caused by natural pleasures such as eating or sex. This almost guarantees continued use.
Eventually, body systems adapt so that an ever-increasing volume of chemicals is needed just to feel normal. Soon, instead of getting high with heroin, the user is sick and in pain without it. Withdrawal symptoms should end after a few days once sober, but cravings can last for months and return years later.
Addiction is a growing loss of self-control and free-will.
Slowed breathing and heart rate are among the immediate physical effects of opiate abuse. Increasing dosage can cross a fine line — a line that is different for everyone — and cause your lungs to stop pumping air. If the dose is strong enough, your heart may stop before you have time to suffocate.
Death is the quickest potential consequence of heroin or prescription pill abuse. A longer-term consequence is dependence and the risk of addiction. Blood and heart diseases are also a risk.
Long term, opioid abuse hijacks your brain’s reward and pleasure circuitry, thus preventing you from functioning normally — and screws up your life.
A healthy brain is a blob of reason, memories and lessons-learned balancing a powerful core of instinct, reflex, pain and pleasure.
“There is no good or bad here. The balance is the good thing and the imbalance between those two forces is the bad thing,” explains Dr. Ruben Baler, a scientist and lecturer for the National Institute on Drug Abuse, an agency of the federal Department of Health and Human Services.
That balance isn’t innate and it isn’t a question of will-power or morality, it’s a question of physical connections between brain cells.
The human brain develops from early childhood into the mid 20s through the pruning of connections among neurons and the insulation of others, creating efficient pathways for the mental processes the individual needs and uses regularly.
“Any substance abuse during this period, including marijuana or alcohol use, strongly increases the chances of addiction in later life,” Baler said.
“If you’re 13 and you start to drink, you have a 47 percent chance that you’re going to be addicted ... if you wait until you’re 14, or 15 or 16, for every year that you wait to start drinking your risk for an addiction goes down significantly,” said Dr. Marisa M. Silveri, a Harvard-affiliated neuroscientist and professor of psychiatry, speaking last year.
Baler draws the analogy to a computer. The brain is programmed, primarily in childhood and adolescence, in response to experience.
“Drugs are like computer viruses, they hijack those programs that are being written,” Baler said.
The result is heroin users risk heart valve infections, HIV, gangrene, Hepatitis C, accidental poisoning, diminished brain function. On the outside, life becomes all about finding more of the drug.
“Humans come with different flavors of brain, different architecture, different operating systems — and some will be more vulnerable to drugs,” Baler said. Environment and circumstances also strongly influence both the decision to try drugs in the first place and susceptibility to addiction.
Anxiety and stress, mental illnesses such as depression or bipolar disorder, post-traumatic stress disorder — brought on by things like childhood abuse or war — can push people to drugs in a conscious or unconscious attempt to self-medicate. Genetics, an uncontrollable factor, account for as much as half of a person’s risk of becoming addicted to any substance, according to NIDA.
Doug Grote, a Greenfield social worker and therapist who sees a full range of patients but who entered the field through his interest in addiction, takes an anthropological view. Human brains are awash in natural chemicals designed to reward and reinforce things like work, love and basic self-preservation.
“Our nervous systems evolved to be looking for danger all the time,” Grote said.
In the absence of hostile tribes and large animals to be fought with spears, responses designed for real danger are triggered by lesser problems.
“So we have a lot of anxiety, we have a lot of depression. Taking a drug for those things is sort of a pseudo-coping skill.”
There is also the risk of a purely inadvertent slide into dependence and addiction through long-term use of painkillers prescribed for legitimate medical conditions, and a fair amount of gray-area on either side.
Baler said it’s not an easy thing to pin down, but the addiction rate in response to long-term opiate or opioid use, heroin or pills, is probably 20 to 30 percent of users.
Method of administration is the single biggest deciding factor, he said. Injection is often viewed as a sign of deep addiction; sticking a needle in your arm demonstrates a stronger need than snorting a line of powder, but there’s something else at work, too.
Injecting and smoking heroin or pills delivers the drug to its targets in the brain faster, and dopamine levels spike faster and harder, Baler said. Not only are drug users likely to begin injecting after they are already chemically dependent, but injecting will incrementally increase the need.
Drug addicts aren’t zombies. If you can recognize a problem you can stop it, although recognizing it is difficult enough with less than 6 percent of drug users perceiving a need for help, according to researchers. Addiction can alter a person’s perception of the outside world, skewing their view of reality.
“The possibility is always there and you can muster other resources. The brain is an exquisitely plastic organ, and you can muster, you can strengthen, you can train lots of different mechanisms,” Baler said. “This is what treatment is trying to achieve, trying to energize and empower other areas of the brain, not those that are impacted. Those will come online, hopefully, later in the healing process.”
The good news is recovery is always an option. The bad news is there isn’t an absolute cure for addiction.
“Even after a long period of time, those trenches that addiction has been digging for years are very difficult to completely cover up; they’re always there, hidden,” Baler said.“We’ve stopped talking at this point in terms of curing addiction, but of just managing it on a chronic basis.”
In other words, you’re always recovering, never cured.
The brain recovers, regains interest in things that were important to the person before they became addicted — exercise, hobbies, relationships — but the risk of relapse remains.
NIDA estimates the relapse rate for drug addiction at 40 to 60 percent. The positive outlook: this means the percentage of recovering addicts who don’t relapse is also as high as 60 percent.