Two new NIDA initiatives address the accelerating increase in abuse of opioid pain medications and bring a powerful new transdisciplinary conceptual framework called social neuroscience to bear on the broad questions of abuse and addiction. Together, the initiatives exemplify the depth of NIDA-supported research capabilities and the flexibility that makes it possible to respond quickly to new patterns in drug abuse and to incorporate innovative research approaches.
Abuse of Opioid Pain Medications
Opioid analgesics, medicine's most effective tools for relieving severe and chronic pain, are being diverted and abused on an alarming scale. In 2003, an estimated 31.2 million Americans aged 12 or older abused a prescription pain medication (took the drug for the feeling it produced, not the condition for which it was prescribed) at least once, an increase of more than 1.5 million over the year before. The prevalence of opioid analgesic abuse is alarming among adolescents; in 2003, high school seniors abused opioids more than any other illicit drug except marijuana.
The abuse of opioids by adolescents is a major focus of NIDA's research. Most of our understanding of opioid abuse and addiction is derived from research in 20- to 40-year-olds; however, exposure to opioids during adolescence—a critical time for brain development—may result in neurobiological changes and behavioral consequences that differ from those in adulthood. NIDA's initiative will help determine how short-term and chronic opioid administration affect the developing brain. Among the important questions are: Does exposure to these medications in one's teens and early 20s increase the likelihood of abuse later in life? Will adolescents who have been treated with opioids or abused them require higher therapeutic doses as adults to achieve adequate pain management?
In addition to intensifying our investigations of opioids' effects in adolescents, the initiative will stimulate research into questions that apply to the elderly, who might be at increased risk for developing addiction because of age-related changes in metabolism or because they are taking other medications. We also need research that tells us whether pain patients are more vulnerable or less vulnerable to the addictive effects of these drugs, and how best to treat co-occurring pain and addiction. Can we develop medications that act at the site of pain rather than deep within the central nervous system, as opioids do? NIDA's intensified investigation will help assure that pain patients have the treatment they need, with medications carrying the smallest possible risks for abuse and addiction.
Social Neuroscience
Researchers have described in detail many of the biological variables in drug abuse and addiction, and they have identified a wide array of social circumstances that foster or protect against the problems that NIDA is dedicated to reducing and eventually eliminating. Our newest initiative will merge these historically separate investigatory realms to examine how neurobiology and the social environment interact in the processes of initiation, maintenance, relapse to, and treatment of abuse and addiction.
Our social neuroscience initiative will help us better understand how neurobiological mechanisms and responses—genetic, hormonal, and physiological—underlie, motivate, and guide social behaviors related to abuse and addiction. In one example of such a relationship, NIDA-funded scientists recently found that when they transferred monkeys from isolation to group living, the animals that became dominant in the new social structure underwent biological changes that resulted in stronger limbic dopamine signaling and less interest in cocaine compared with the animals that became submissive (see "Social Environment Appears Linked to Biological Changes in Dopamine System, May Influence Vulnerability to Cocaine Addiction," NIDA NOTES Volume 17, No. 5). A social neuroscience perspective might also investigate the neurobiological mechanisms underlying the heightened sensitivity to social influences and decreased sensitivity to negative consequences that—together with other special characteristics of their age—make adolescents particularly vulnerable to drug abuse. In adults, too, the confluence of the brain's neurobiological response to drugs and influences from the social environment can have a profound impact on whether an individual begins, continues, or quits abusing drugs. In addition to new insights into the initiation and consequences of drug abuse, social neuroscience might help explain how group, 12-step, or faith-based interventions might bring about positive change.