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This is your brain on drugs: haywire

The disease of addiction creates a chemical imbalance

By Mary Meehan

MMEEHAN1@HERALD-LEADER.COM

Understanding the reaction of the brain to drugs is key to successfully addressing substance abuse — a disease that annually causes nearly 120,000 deaths in the United States and costs billions of dollars, according to the Robert Wood Johnson Foundation.

"Of all preventable deaths in the United States, substance abuse causes more death, more illness and more disabilities than any other disease," said Sue Rusche, director of National Families in Action, a non-profit that works to prevent drug abuse.

Even though the American Medical Association officially declared substance abuse a disease in 1966, some think it is somehow a moral failing. Alcoholism and addiction are still widely viewed as problems that can be overcome with willpower and, perhaps, prayer.

If the public can grasp that addiction is a disease, "maybe it chisels away some of the preconceived idea that these are just bad people," said Shelly Schwartz-Bloom, a professor of neurobiology and biological psychiatry at Duke University Medical Center.

The effect of addictive substances on the brain might chemically impair key survival functions — eating, drinking, even reproduction. Substance abuse also appears to interfere with the chemical wiring that connects emotion to action, which could account for why alcoholics and addicts often seem immobilized and unable to help themselves.

Addictive substances — alcohol, painkillers, amphetamines — all interact with the part of the brain known as the reward pathway. That is one reason addiction is so difficult to treat, said David Friedman, a professor at Wake Forest University and an expert on addiction. Studies have shown that the effect on the reward pathway is so strong that monkeys given cocaine each time they push a lever will keep tapping until they overdose and die.

Drugs "deliver what they promise," he said.

At first. The overuse of drugs or alcohol causes the brain to actually change its function in an effort to return to a natural balance. Yet that change sets up the intense craving that traps addicts in a self-defeating cycle, said Friedman.

"It's not magic," said Schwartz-Bloom. "Something happens biologically."

To the addicted brain, the abused substance is something needed to survive, said Dr. Karen Miotto, an associate clinical professor at the University of California. But the initial pleasant feelings become elusive, and addicts continue to drink or use drugs simply to feel normal.

Relapse is another confounding part of addiction. But relapse is common in many other areas of health, said Miotto. For example, some people stop taking their medication for high blood pressure or heart failure.

The length of treatment is key to who gets clean and sober and stays that way, research has found. Although it varies by individual, 90 days seems to be a milestone for successful treatment. That treatment could be anything from inpatient hospital stays to group therapy.

But, Miotto said, a single exposure to treatment is often expected to work with substance abuse. "We would never say, 'We are going to intensively treat your hypertension for three months,' and that's it," she said.