Addiction researchers and treatment professionals have long known that drug addiction and alcohol abuse are closely associated. In the last decade, research has broadened our understanding of many behavioral mechanisms common to both disorders. Yet, while two in five patients are addicted to both drugs and alcohol, the treatment they are likely to receive will target only one disorder. A lack of science-based information on alcohol and addiction treatment of drug and alcohol abuse limits the ability of treatment professionals to provide the comprehensive treatment these patients need.

Recent research suggests some medications developed to treat addiction or alcohol abuse may be useful for treating both alcohol and addiction. 

This information, along with our increased understanding of the underlying factors that drive drug and alcohol abuse, provides a strong rationale for a coordinated research effort to meet the critical need for treatments for people suffering from both disorders. Toward that end, NIDA and the National Institute on Alcohol Abuse and Alcoholism (NIAAA) have issued a joint program announcement to spur both drug and alcohol abuse researchers to investigate all aspects of pharmacological treatment for dually addicted patients.

Coordinated research on addiction and alcohol patients will address the needs of the overwhelming number of Americans who abuse both alcohol and illicit drugs. More than 2.4 million of the 5.6 million people who abused illicit drugs in 2001 also abused alcohol, according to the National Household Survey on Drug Abuse. In fact, the more heavily someone abused alcohol, the more likely he or she was to use illicit drugs, the survey found. In 2001, nearly two of every three American teenagers, ages 12 to 17, who engaged in frequent drinking binges also abused drugs. In comparison, only 1 in 20 young people who didn't drink at all used drugs.

The substantial portion of addiction and alcohol abusing patients in community treatment programs provides additional evidence of the need for science-based information on treating dual addiction. Patients who abuse both drugs and alcohol accounted for more than 42 percent of admissions to substance abuse treatment facilities reported by State agencies in 2000, the last year for which these data are published. Alcohol abuse is even more likely among patients who abuse certain drugs, such as cocaine, methamphetamine, and marijuana. For example, more than half of cocaine-abusing patients who entered treatment in 2000 also abused alcohol.

We aim to generate a broad spectrum of useful clinical information about appropriate sequencing or combining of medications and behavioral therapies, possible drug interactions that could affect optimal dosages, and unique requirements of specific groups of dually addicted patients...

To develop effective treatments for patients who have addiction and alcohol dependence, we need to understand why so many people do so. Part of the answer probably has to do with genes--underlying genetic variations that may play a role in common brain mechanisms that fuel both disorders. NIDA-supported brain imaging studies conducted at Brookhaven National Laboratory in Upton, New York, have documented similarities in the structure and function of the brains of alcoholics and chronic cocaine abusers that appear to be implicated in the abuse of both substances. Individuals with either disorder have low levels of dopamine D2 receptors in the brain's reward pathways that may impair their capacity to derive pleasure from normally rewarding activities. This deficit may make them more vulnerable to the rewarding effects of alcohol and cocaine.

Individuals with addiction and alcohol dependence also may combine alcohol and illicit drugs because of interactions between abused substances in the body. Because both drugs and alcohol activate brain areas involved in reward, combining substances may increase these effects. Other alcohol-drug interactions may counter unpleasant effects that often accompany or follow substance abuse. Clinical reports suggest that cocaethylene, a combined cocaine-alcohol metabolite that is formed in the body following concurrent alcohol and cocaine use, appears to reduce the anxiety that can accompany cocaine use. Recent research in rats confirms that cocaethylene plasma levels remain high as cocaine levels fall, producing a delayed, relatively long-lasting rewarding effect that may counter the aversive effect induced when cocaine plasma levels recede.

While the perceived benefits of combining alcohol and drug addiction may play a big part in the high percentages of people who do so, the addictive effects and harmful consequences of both substances increase when they are used together. Dually addicted patients are more likely to drop out of treatment and have poorer results than patients who abuse only one substance. However, since most studies on treating drug and alcohol abuse have examined these disorders separately, drug and alcohol treatment counselors now have little science-based information on which to base their treatment of these patients.

Drug addiction and alcohol abuse wreak incalculable damage on individuals, families, and communities. When they occur together, these disorders double the challenge to researchers and treatment providers. Now, NIDA and NIAAA have launched a concerted scientific response to address these challenges. Ultimately, this expanded research will fuel the development of new treatments that will enable substance abuse treatment programs to more effectively meet the needs of the many patients who abuse both alcohol and illicit drugs.

The National Institute on Drug Abuse (NIDA) is part of the National Institutes of Health (NIH) , a component of the U.S. Department of Health and Human Services.