States (Wright et al., 1997). Policy makers urgently need to know the feasibility and possible benefit of expanding the size and coverage of the drug treatment system to reach individuals not currently receiving treatment.
With these points in mind, we offer in this chapter recommendations for continuous improvement of the science of drug treatment, but also for improved estimation of drug treatment effect sizes to support cost-effectiveness and benefit-cost analyses that can inform policy makers. Both goals require increased attention to potential threats to the validity of inferences from treatment outcome studies.
When complete and permanent abstinence is used as a criterion of success, between 60 and 90 percent of clients relapse to drug use within 12 months of treatment; relapse rates are similarly high for tobacco and alcohol treatment (Phillips, 1987). Thus, many outside the treatment community have expressed skepticism about the benefits of funding drug treatment.
To some extent, this skepticism is based on unrealistic expectations. In addition to their drug abuse, heavy drug users frequently suffer from various other “co-morbid” conditions—other mental and physical health problems, economic and family problems—that greatly complicate treatment. Moreover, epidemiological, behavioral, genetic, and neuropsychological research suggest that many of those at highest risk for drug dependence and other patterns of antisocial behavior show early and persistent deficits of cognitive functioning and impulse control that may reflect neurological deficits (e.g., Moffitt, 1993). Finally, as we note in Chapter 2, it has become clear that psychoactive drugs have profound and possibly chronic effects on brain functioning, which leaves the person biologically vulnerable to relapse long after the immediate signs of addiction have been alleviated (Leshner, 1997).
Thus, drug dependence is increasingly seen as a chronic relapsing brain disorder (O’Brien and McLellan, 1996; Leshner, 1997), for which
According to the Treatment Episodes Data Set (TEDS), heroin and other opiates accounted for 16 percent of the approximately 1.5 million annual treatment admissions in 1997—the largest category of admissions (Substance Abuse and Mental Health Services Administration, 1999, http://www.samhsa.gov/oas/TEDS/TEDSReport97.pdf). Of these, 42 percent (approximately 100,000) were assigned to methadone maintenance treatment. The Uniform Facility Data Set (Substance Abuse and Mental Health Services Administration, 1997, p. 36) indicates that 138,000 of all clients in treatment (15 percent) were receiving either methadone or LAAM. The American Methadone Providers Association cites a higher figure on the number of people currently on methadone maintenance: 170,000.