presented by Nora D. Volkow, M.D. Director, National Institute on Drug Abuse National Institutes of Health Department of Health and Human Services
Testimony before the House and Senate Subcommittee on Labor-HHS-Education Appropriations
Statement for the Record
Mr. Chairman and Members of the Subcommittee:
I am pleased to present the Fiscal Year (FY) 2008 President's budget request for the National Institute on Drug Abuse (NIDA). [The FY 2008 budget included $1,000,365,000. Today, I will discuss NIDA's multifaceted strategy to help reduce the enormous toll that drug abuse and addiction take on this Country, highlighting recent scientific accomplishments, novel approaches to prevention and treatment, as well as our strong collaborations with other NIH institutes and with the Substance Abuse and Mental Health Services Administration (SAMHSA).
Drug abuse and addiction are a major burden to society; economic costs alone are estimated to exceed half a trillion dollars annually in the United States - including health, crime-related costs, and losses in productivity . However, as staggering as these numbers are, they provide a limited perspective of the devastating consequences of this disease.
The National Institute on Drug Abuse, within the National Institutes of Health, is pleased to again report continuing declines in both licit and illicit drug use, particularly among our Nation's youth. In fact, NIDA's latest Monitoring the Future (MTF) survey results show a 23 percent decline over the last five years in any past-month illicit drug use by students in the 8th, 10th, and 12th grades combined. Declines in teen cigarette smoking, now at its lowest rate since the survey began in 1975, signal particularly good news since this will translate not only into decreases in cancer-related mortality but also decreases in deaths associated with the myriad medical consequences of smoking (i.e., chronic obstructive pulmonary disease, asthma, premature birth, sudden infant death syndrome, and more).
Although abuse of most licit or illicit substances has decreased, such is not the case for prescription medications, particularly for opiate analgesics, which have produced steep increases in abuse-related emergency room admissions. The abuse of prescription medications occurs at all ages. However, it is particularly problematic in adolescents since this is the time when individuals are most vulnerable to addiction. The MTF revealed that in 2006, prescription medications, along with over-the-counter drugs (cough medicine), accounted for five of the top six drug abuse categories reported by 12th graders, marijuana still the most frequently abused illegal drug. Second in frequency of abuse was the prescription painkiller Vicodin, with roughly one in ten seniors reporting abuse during the past year. Amphetamines ranked next, followed by over-the-counter cough medicines, with roughly 8 and 7 percent of 12th graders, respectively, reporting past-year abuse in 2006.
Prevention Efforts - Genes, Environment, and Development
Because adolescence is typically when drug abuse and addiction take hold, NIDA continues to focus research on this vulnerable period of development. Given that the brains of adolescents have not fully developed, including the connections between brain areas involved with emotions and areas involved with judgment and decision-making, adolescents are less able to exert inhibitory control over emotions and desires and are hence more likely to engage in risky behaviors, including drug experimentation. However, the brain at this stage is also inherently more plastic, which offers opportunities for prevention interventions that could lead to greater resilience.
Addiction results from the complex interaction of drugs, genes, and environmental and developmental factors. Thus NIDA has made the study of these interactions a priority, joining with other Institutes and organizations to support relevant research. Particularly relevant to substance abuse is the social environment, as genetic and imaging studies continue to reveal how the interplay of biological (i.e., genes, developmental stage) and social influences (i.e., family, peers, culture) affect individual choices and decisions about drugs. This knowledge is crucial to our future ability to tailor prevention interventions to address the risk areas of a given individual.
NIDA also encourages and supports the development of next generation technologies to identify and catalogue the multiple functional changes to the DNA (i.e., "epigenetic" modifications) that can result from environmental variables, such as quality of parenting, stress, and exposure to drugs. This avenue of approach requires support of research to develop standardized and comprehensive "phenotypes" of social environments (including family, peers, school, neighborhood, community, and culture) that can be monitored at various stages of a person's life. A better understanding of the neurobiology of social behaviors is relevant both for the treatment of drug addiction as well as mental illness, which also involves social aspects of human behavior and frequently co-occurs with substance abuse.
Treatments - Novel Approaches
Historically, addiction therapies have targeted the brain's reward system to try and interfere with the pleasurable effects of drugs of abuse. Now, however, scientists have also identified the broader brain circuits that underlie fundamental aspects of drug abuse and addiction, such as craving, euphoria, motivation, learning, memory, interoception (i.e., sensitivity to internal stimuli such as hunger, pain), and inhibitory control - key contributors to addiction. These discoveries open wide the range of novel targets for different treatment approaches.
The recent discovery that stroke victims who suffered damage to their right insula (a brain area involved in emotional experience and interoception) dramatically reduced their smoking behavior points to new directions in addiction treatment. Specifically, findings suggest that strategies to noninvasively affect activity in the insula may be beneficial for addiction. These include use of technologies such as rTMS (repetitive transcranial magnetic stimulation), a noninvasive method to influence brain activity in specific regions, or "neurofeedback," where patients learn to regulate specific regions in their brains by getting feedback from real-time brain images. Though not yet demonstrated for addiction, these techniques have shown promising results in depression and in the management of pain. They also open up a completely new way to develop psychotherapeutic interventions to target specific brain regions or circuits.
New knowledge of how proteins interact with one another in circuits implicated in addiction has prompted the development of novel addiction medications. For example, the cannabinoid receptor system, which regulates the activity of the dopamine system - the common target for the reinforcing effects of all drugs of abuse - holds promise for treating various drug addictions and, interestingly, for obesity as well.
Immunotherapeutic strategies offer another unique approach to relapse prevention. Such strategies are based on the development of vaccines to generate antibodies to the drug that block its entry into the brain and thereby interfere with its effects. Cocaine and nicotine vaccines are already in clinical trials, and NIDA has requested proposals to develop a methamphetamine vaccine.
Putting Research into Practice
A major NIDA objective is to translate findings from basic and clinical research to guide and inform the design of prevention and treatment interventions that can be successfully implemented in real-world settings. People involved with the criminal justice system (6.9 million adult Americans) represent one such group. Approximately half of prison inmates meet criteria for alcohol/drug abuse or dependence, and yet the vast majority return to the community with no treatment . In addition to the resulting high rate of recidivism for drug abuse and re-arrest, a recent study of inmates reported that untreated offenders were 12.7 times more likely to die within 2 weeks post-release than other state residents and that drug overdose accounted for 70 percent of those deaths . Because research has shown that treatment in the criminal justice system works, one of NIDA's initiatives is to support services research to help develop interventions that will be acceptable and sustained in the criminal justice system.
To this end, NIDA created and supports the Criminal Justice Drug Abuse Treatment Studies (CJ-DATS) initiative, an inter-agency collaboration aimed at bringing new treatment models into the criminal justice system to improve outcomes for drug-abusing offenders. To facilitate the translation of treatments to the criminal justice setting NIDA released a landmark publication entitled Principles of Drug Abuse Treatment for Criminal Justice Populations, designed to advance the concept of addiction as a brain disease and to summarize evidence-based principles for treating addiction in criminal justice settings.
NIDA's Drug Abuse Treatment Clinical Trials Network (CTN) also plays a key role in bringing evidence-based treatments to community settings by testing the effectiveness of new interventions and by training providers in the implementation of research based practices in order to promote their acceptance and adoption in the community. To further enhance the dissemination and utilization of research findings and to expand the involvement of the medical community in the screening and treatment of drug abuse, NIDA has launched a new "NIDA Goes to the Doctor" initiative. As part of this initiative, NIDA recently established four Centers of Excellence for Drug Abuse Information, in collaboration with the American Medical Association, with the aim of advancing addiction awareness, prevention, and treatment in primary care practices.
Drug abuse plays a significant role in the spread of HIV, not only via injection drug use but also by increasing risky sexual behaviors. The addictive and intoxicating effects of many drugs can alter judgment and inhibition and lead people to engage in impulsive and unsafe behaviors. Drug abuse and addiction can also worsen the progression of HIV and its consequences, especially in the brain. Thus NIDA is supporting preclinical and clinical studies that examine the interactions between: drugs of abuse and HIV medication, HIV and plasticity (relative to changes that lead to addiction), and HIV and neurotoxicity (with regard to the adverse drug effects that result in neurodegenerative conditions such as dementia and parkinsonian symptoms).
While all groups are affected by HIV/AIDS, not all are affected equally. African Americans bear a disproportionate burden of HIV/AIDS in the United States, which may in part reflect data showing that African Americans are predominant among those who become aware of their infection at later stages in the disease process, and who therefore represent lost opportunities for treatment. Because early HIV detection helps prevent its transmission and increase health and longevity - and is as cost-effective as screening for other conditions such as breast cancer and high blood pressure - NIDA is supporting research to make testing more acceptable in communities nationwide. To this end, NIDA recently held a meeting aimed at improving the rates of HIV screening, and is now incorporating the resulting recommendations, which include addressing associated stigma and optimizing early diagnosis and follow-up linkages to care.
NIDA's comprehensive research portfolio is strategically positioned to capitalize on new scientific opportunities. Groundbreaking developments in the field of genomics signify an exciting era of research whereby we will be able to identify genes that make a person more vulnerable to drug abuse and addiction and devise counter strategies. We work toward a future in which early recognition of risk for addiction is no different than early recognition of other chronic medical diseases. Innovative use of imaging techniques allow scientists to design better treatments and more precisely judge their effectiveness, even predicting who would be most likely to benefit from selected therapies and who might be expected to relapse, so that preemptive interventions can be applied. Finally, advances in proteomics will help in designing much more sensitive tools to detect drug exposures and their consequences for individuals, heralding a future where diagnostic kits may be used to screen for drug abuse in the medical setting.
Thank you, Mr. Chairman. I will be pleased to answer any questions the Committee may have.