There was a time when the nation's crime rate was front-page news. In the 1990s, the crime rate began to drop and we worried less. But a preliminary report released by the FBI in June shows an increase in robberies and violent crime in 2005. Inasmuch as drug abuse can facilitate criminal behavior, this is a good time to take a closer look at how the science in substance abuse has started to provide some answers on how to solve these problems.

The crimes associated with drug abuse include sale or possession of drugs; property crimes or prostitution to support drug habits; and violent crimes reflecting out-of-control behavior. In fact, offender drug use is involved in more than half of all violent crimes and in 60 to 80 percent of child abuse and neglect cases. It is estimated that 70 percent of the people in state prisons and local jails have abused drugs regularly, compared with approximately 9 percent of the general population.

In 2002, approximately 60 percent of male juvenile detainees and 46 percent of female detainees tested positive for drug use. The estimated cost to society of drug abuse in 2002 was $181 billion — $107 billion of it associated with drug-related crime.

When drug abusers enter the criminal justice system, it signals a pivotal crisis in their lives. It also offers a unique opportunity to institute treatment for drug abuse and addiction. Studies have consistently shown that comprehensive drug treatment works. It not only reduces drug use but also curtails criminal behavior and recidivism. Moreover, for drug-abusing offenders, treatment facilitates successful re-entry into the community. This is true even for people who enter treatment under legal mandate.

In a Delaware work-release research study sponsored by the National Institute on Drug Abuse, those who participated in prison-based treatment — followed by ongoing post-release care — were seven times more likely to be drug-free and three times more likely to be arrest-free after three years than those who received no treatment. Other studies report similar findings. The Substance Abuse and Mental Health Services Administration reports that substance-abuse treatment cuts drug abuse in half and reduces criminal activity by as much as 80 percent.

If treatment works, then why have some communities resisted offering comprehensive treatment programs to drug-abusing offenders? One reason is that addiction is still often seen as something for the individual to deal with. The other is the cost.

Science now tells us that repeated drug exposure affects the areas of the brain that enable people to exert control over their desires and emotions, which may explain why it is so difficult for an addict to abstain. Drugs also affect areas of the brain responsible for the perception of pleasure and punishment, for learning and cognition, and for motivating our behaviors. These findings have led to the idea of addiction as a complex disease of the brain that cannot be managed with a stern moral lecture — or even with a period of forced sobriety in jail. If we understand that, we can better understand how to manage drug-abusing offenders.

Some reject the concept of addiction as a disease on the grounds that it removes responsibility from the addict. But, in fact, it gives the addicted person the responsibility for seeking and maintaining treatment for the disease, just as is the case for other diseases.

Some courts and communities have also resisted offering comprehensive treatment because of fears of high costs. But recent studies show it is actually less expensive for communities to treat drug-abusing offenders than to let them sit in jail or prison. It is estimated that every dollar invested in addiction treatment programs yields a return of $4 to $7 in reduced drug-related crimes. Savings for some outpatient programs can exceed costs by a ratio of 12 to 1.

Some criminal justice systems are working on innovative approaches to dealing with drug-abusing offenders. In Cook County, Ill., NIDA sponsors a pilot project that trains judges on how addiction affects the brain so they can be better prepared to place addicted defendants in adequate treatment environments. Last month, NIDA released a report titled "Principles of Drug Abuse Treatment for Criminal Justice Populations." These principles emphasize the need for customized strategies that can include cognitive behavioral therapy, medication, and consideration of other mental and physical illnesses. Continuity of care after re-entry into the community is also essential.

The ultimate goal of treatment is to help an addict stop using drugs. As a clinician, I don't remember ever meeting an addicted person who wanted to be addicted or who expected that compulsive, uncontrollable or even criminal behavior would emerge when he or she started taking drugs. Providing drug-abusing offenders with comprehensive treatment saves lives and protects communities.

Nora D. Volkow is director of the National Institute on Drug Abuse, a component of the National Institutes of Health. She wrote this commentary for The Washington Post.