"Why can't you just stop?"
This familiar, plaintive cry from the family and friends of someone suffering from addiction reflects a common misunderstanding. The myth of addiction as a moral failing or a matter of willpower has given way to increased awareness of addiction as a primary disease affecting brain function and behavior.
An addicted person continues to seek out and use drugs despite terrible consequences — illness, accidents, lost jobs, ruined friendships, shattered families, financial destruction and incarceration. But with an understanding of the ways that drug use changes brain chemistry, structure and function, friends and family will be less baffled by these persistent, damaging behaviors.
Your brain on drugs
The idea of addiction as a brain disease has advanced dramatically since the 1987 public service announcement showed a sizzling egg in a frying pan while a voiceover intoned, "This is your brain on drugs." The idea that someone "fried" his mind with drugs does have an element of truth — drug use does alter the brain.
Veena Kumari is chief scientific officer of Sovereign Health, a group of addiction and mental and behavioral health treatment centers headquartered in San Clemente, with nine facilities in five states. Kumari said there are chemical, structural and functional differences in the brains of healthy people and those with drug and alcohol addiction. Cognitive functions like inhibition, attention, learning, memory and motivation can be harmed by substance abuse.
Treating addiction as a brain disease doesn't mean people suffering from addiction are hapless victims of uncontrollable forces. A combination of medication, and behavioral therapy and cognitive exercises can help retrain the brain to counteract addictive tendencies and establish healthy patterns of reward and motivation.
Scrambled messages and overstimulation
When smoked, injected, inhaled or swallowed, drugs, including alcohol, tamper with the brain's communication system, interfering with normal transmission of information.
For instance, the chemical structure of both marijuana and affect the brain's opioid and cannabinoid receptors, both of which are neurotransmitters, a type of brain chemical. The similarity tricks receptor cells in the brain by sending abnormal messages. Amphetamines and cocaine trigger a surge of neurotransmitters, overloading the brain with chemicals in quantities too large to process.
As a result, the brain signals that drive thoughts and behavior can become severely disrupted.
In its normally elegant system of pleasure and memory, brain wiring ensures the repetition of healthy behaviors like eating and drinking water. These activities produce pleasurable feelings — rewards that the brain remembers. This reward system trains us to repeat the healthy behaviors that we need to stay alive.
Eating, exercise, sex and other healthy activities produce dopamine, a neurotransmitter, in the regions of the brain that govern movement, emotion, motivation and feelings of pleasure. Drugs overstimulate the brain's reward system by inundating the circuit with two to 10 times the amount of dopamine that normal pleasurable activities produce.
"The effect most consistently seen across all addictive drugs is the surge in dopamine in the brain's reward system, particularly the nucleus accumbens," Kumari said. The nucleus accumbens, a region located in the front of the brain, plays a critical role in processing pleasurable stimulation and reinforcing repetition of the action that produced the reward.
When altered by drugs, brain mechanisms that prompt you to drink water when you're thirsty or perform other healthy tasks create an urge to use the harmful substance.
Recreational use vs. addiction
The chance a drug user will become addicted depends largely on the speed, intensity and reliability of the dopamine surge, Kumari said. "Smoking or injecting a drug produces a stronger, faster dopamine release, and is more likely to lead to addiction than other methods, such as swallowing a pill with the same substance."
Smoked and injected drugs enter the brain immediately, sparking a powerful pleasure rush. With many drugs, that high recedes quickly. Researchers think this spiking high followed by a plummet back to normal brain chemical levels impels some people to keep taking drugs to relive the short-term pleasure.
Harder to feel happy
Continued drug use causes lower production of dopamine in the brain and a reduced number of dopamine receptors. The addicted person gets less pleasure from consuming the drug, so higher quantities are needed to achieve the previous high.
"The memory of this desired effect and its association with the drug is a conditioned response that underpins the addicted person's continued, compulsive drug-seeking behavior," said Kumari. "It also explains why some people in recovery remain at risk of relapse even after years of abstinence."
Impaired learning and decision-making
Along with wreaking havoc on the brain's reward system, continuing to smoke, snort, shoot up or swallow drugs or drink excessively damages the brain's frontal cortex. This is the critical thinking center of the brain that drives executive function — the capacity to plan, solve problems, pay attention, make decisions and control impulses. Drug-induced disruption of the prefrontal cortex, the foremost section of the brain, contributes to drug cravings, continued compulsive use and ongoing denial of the addiction problem.
"The still-developing brains of young adolescents are particularly vulnerable to adverse environmental influences and drugs of abuse," said Kumari. This susceptibility to brain damage makes drug use during pregnancy, childhood or adolescence especially risky.
"How could you do that?"
For people suffering from addiction, impaired impulse control and flawed decision-making processes in the brain cause behavior that often stuns their loved ones: continuing to buy and use drugs when there's no money for food, driving drunk or high, not showing up for work and other destructive actions.
Those dealing with addiction also suffer from a decreased ability to learn and remember, due in part to lower glutamate concentration in the brain. Glutamate is a potent neurotransmitter that plays a key role in learning and memory. The addicted person ruefully described as someone "who used to be so smart" may have damaged glutamate receptor cells in the brain.
As addiction progresses and behavior patterns repeat, family members feel angry and desperate and the addict feels hopeless. But treatment can manage and even reverse these brain patterns, replacing them with healthy behaviors.
Neurology and sociology interact
Social and environmental risk factors influence drug use, too. These include culture, family and peer pressure, social support, poverty and availability of drugs.
A family pattern of drug use or antisocial or criminal behavior, childhood physical or sexual abuse, emotional abuse or neglect from parents or caregivers, and drug-using peers are common risk factors, Kumari said.
"These factors affect the person adversely through lack of — or inappropriate — role models and learning opportunities, lack of emotional support, constant threat, trauma, elevated stress, poor coping skills, and lack of natural rewards such as praise," she said.
A genetic influence
Genetic factors account for between 40 and 60 percent of a person's vulnerability to addiction, according to the U.S. government research organization National Institute on Drug Abuse. Although no "addiction gene" has yet been identified by researchers, the interplay among addiction "running in the family," individual lifestyle decisions and external influences is complex.
"There is little doubt that certain genes confer risk of addiction. However, even with exactly the same degree of genetic risk, some people will and others will not become addicted," Kumari said. "This depends on multiple factors, such as social support or cultivated coping skills that influence the expression of genes involved."
For example, patients with risk factors predisposing them to addiction may follow their doctor's orders by taking an appropriate dose of an opioid medication prescribed for pain after an accident or injury, and become addicted.
Beth Darnall, clinical associate professor in the division of pain medicine at Stanford University and author of "The Opioid-Free Pain Relief Kit," said that pain treatment plans should take into account the patient's risk for addiction while teaching pain management skills.
Treatment provides solutions
Treating addiction requires a holistic approach, Kumari said. Treating symptoms alone is insufficient. The focus must go beyond an emphasis on not drinking or using drugs, which is akin to treating a chest cold in an HIV patient without treating the HIV.
Kumari said that for treatment to be effective, it must take into account both behavior and biology. "We cannot view mind and body — or brain, in this case — as separate entities," she said.
Specialized talk therapies, such as the cognitive behavioral approach, produce positive changes in behavior as well as changes in the brain, Kumari said.
"The target clinical outcome for addicted people should not be just achieving abstinence in the short term," she said. "Successful treatment needs to include abstinence maintenance and long-term rehabilitation for addicts so they become productive members of society."
Sovereign Health's treatment approach includes pharmacological therapies to reduce withdrawal symptoms and maintain abstinence from drugs or alcohol in the long term. Medicines and cognitive behavioral therapy can help those in recovery address psychological dependence, stress and emotional issues, Kumari said. At Sovereign, family therapy also helps the addicted person get off drugs and helps prevent relapse down the road.
Cognitive remediation therapy, a technique using drills and practice to improve attention, memory, planning and other abilities, can help people suffering from addiction improve or recover lost brain functions. Other interventions, such as meditation to promote well-being, are also important parts of a comprehensive addiction treatment plan.
"Improving cognition and promoting brain wellness is crucial for improving long-term treatment outcomes for addiction," she said.