Prevention and Treatment of Addiction

The next decades will witness the approval of medications currently in early development to treat various phases of addiction. Potential candidates include a CRF antagonist, a CB₁ receptor antagonist, and a D₃ partial agonist. All hold great promise for sustaining abstinence or preventing relapse. Examples of marketed medications being tested for treating withdrawal and facilitating early abstinence in patients who are actively using addictive drugs include buspirone(Drug information on buspirone) and nefazodone(Drug information on nefazodone) for marijuana, and bupropion, modafinil(Drug information on modafinil), and extended-release methylphenidate(Drug information on methylphenidate) for stimulants.¹¹ These are all in proof of concept or confirmatory trials as potential antiaddiction medications.

In the next decade, our understanding of the phenotypes of patients who are addicted will be greatly enhanced through research that is aimed at defining and measuring aspects of the social environment—culture, neighborhoods, schools, families, and peer groups—to better understand how genes can mitigate or amplify social influences that are known to powerfully affect individual choices and behaviors related to substance abuse. Complementing these efforts, NIDA will focus on pharmacogenomics, the study of how genes regulate an individual's response to drugs and medications. Clinical and genetic biomarkers are being pursued in genetic research and in pharmacogenetic studies and are being incorporated into enrichment medication and behavioral treatment trials. This research not only will illuminate the physiological mechanisms of drug abuse and addiction but also has the potential to empower clinicians by helping them tailor pharmaceutical interventions to a subgroup of the addicted population who will optimally respond to such treatment—from selecting the most effective medication and dosage regimen to anticipating and avoiding adverse effects.¹⁷

Immunotherapy is another very promising area, reflected in interim analysis data from the nicotine(Drug information on nicotine) vaccine trial. In the next 3 to 5 years, we may have an approved vaccine for smoking cessation. Similar efforts are being pursued for cocaine, methamphetamine, and heroin vaccines. Monoclonal antibody research is still at the preclinical phase, but early data are encouraging and may possibly result in an approved monoclonal antibody to treat cocaine, methamphetamine, or PCP overdoses in emergency departments in the next decade.

Other treatments on the horizon offer promise for affecting the conditioned responses to drugs that go hand in hand with addiction and lead to relapse even after long periods of abstinence. New therapies include those targeting extinction, or the unlearning of conditioned responses,^23,24 and neurofeedback, the use of noninvasive real-time brain imaging technologies to teach patients to regulate neural activity in specific brain regions.²⁵ These novel approaches will take advantage of new technologies, medications, and basic and behavioral research to help us understand and modify the circuitry affected by addiction—part of a wider network in which pathways influence one another in highly complex ways.

For prevention research, the next decade holds promise for better identification of addiction vulnerabilities and high-risk populations based on family history, personality traits, and genetic markers, as these become better characterized. New findings will generate more effective early interventions, which, in turn, should have tremendous effect in preventing development of the full-blown disease. Family and school-based interventions, alone and in combination, offer promising prevention techniques that will be more widely applicable in the next decade.

There is hope for the future of the treatment of addiction, with the political landscape and the public's understanding and acceptance of addiction as a brain disease already changing. It is our hope that this will translate into funding for addiction research and treatment. Our work is cut out for us however:

• Understanding the interplay of genetic and environmental factors in influencing addiction risk will help identify those who are particularly vulnerable to the rewarding effects of drugs.
• Findings will aid the development of increasingly refined prevention strategies directed at selectively mitigating a patient's specific risk factors.
• In a similar vein, identifying patient characteristics that predict the relative efficacy of specific treatment interventions will allow treatment providers to better match patients with treatment services.
• And finally, the development of medications to curb craving—at the forefront of efforts to help drug-addicted patients establish and maintain abstinence in treatment—will be critical to effectively counter chronic, compulsive drug taking.

The reward to society will be tremendous, with many individual lives restored and families reunited. We will see fewer crimes and less jail crowding, fewer new cases of HIV infection and hepatitis C, more productive persons, and healthier and safer communities.