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NIDA. (1997, October 1). Study Sheds New Light on the State of Drug Abuse Treatment Nationwide. Retrieved from

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October 01, 1997
Michael D. Mueller and June R. Wyman

The four most common forms of drug abuse treatment are all effective in reducing drug use. That is the major finding from a NIDA-sponsored nationwide study of drug abuse treatment outcomes. The Drug Abuse Treatment Outcome Study (DATOS) tracked 10,010 drug abusers in nearly 100 treatment programs in 11 cities who entered treatment be-tween 1991 and 1993.

"DATOS is the largest study of drug abuse treatment outcomes since the early 1980s and the most important in the last 10 years in terms of telling us how treatment programs are doing", says Dr. Bennett Fletcher, chief of NIDA's Services Research Branch.

DATOS investigators measured treatment outcomes using a random sample of approximately 3,000 patients. The researchers compared patients weekly and daily drug use for the 12 months before they entered treatment with their weekly and daily drug use 12 months after they stopped treatment. Patients in outpatient methadone treatment who were still in treatment were interviewed approximately 24 months after admission. Other outcomes that the researchers measured included:

  • whether patients reported fewer illegal acts, including assault, robbery, burglary, larceny, forgery, and fencing stolen property;
  • whether patients were working full time, defined as at least 35 hours per week; and
  • whether patients reported fewer attempts or thoughts of suicide, which was used as a marker for depression. The researchers chose that marker because several previous studies had established its validity as an indicator of depression.

The four types of programs with the number of programs that DATOS studied in parentheses were outpatient methadone (29), outpatient drug-free (32), long-term residential (21), and short-term inpatient (14). (For descriptions of the program types, see "Four Common Types of Drug Abuse Treatment") Three of the four types were also studied in DATOS's two predecessors: the Drug Abuse Reporting Program (DARP), which included admissions to treatment from 1969 to 1973, and the Treatment Outcome Prospective Study (TOPS), which covered admissions from 1979 to 1981. The short-term inpatient treatment programs, originally developed to treat alcohol abuse but admitting increasing numbers of cocaine abusers during the 1990s, were studied in DATOS but not in the two earlier projects.

see captionPercentage of Patients Reporting Weekly or More Frequent Cocaine Use Before and After Treatment. In all four types of treatment programs that the Drug Abuse Treatment Outcome Study examined, the percentage of patients reporting frequent use of cocaine dropped dramatically after treatment.
* Outpatient methadone patients still in treatment were interviewed approximately 24 months after admission.

Highlights From the Study

For the four treatment types, DATOS investigators found reductions almost without exception in the use of all drugs including cocaine, heroin, and marijuana after treatment. (See "Percentage of Patients Reporting Weekly or More Frequent Substance Use Before and After Treatment") Likewise, after treatment a smaller percentage of patients reported committing illegal acts, working less than full time, and thinking about or attempting suicide. (See "Percentage of Patients Reporting These Behaviors Before and After Treatment"). The data also revealed that:

  • Except in outpatient methadone programs, cocaine was the primary drug of abuse, with alcohol running a close second. Cocaine abuse was common even in outpatient methadone treatment programs for heroin addicts. About 42 percent of patients who entered methadone treatment programs also abused cocaine.
  • Heroin use had decreased since the 1979 to 1981 period that TOPS studied. Large declines in the abuse of depressants such as barbiturates and tranquilizers had also occurred since TOPS.
  • Short-term inpatient treatment programs yielded significant declines in drug use, even though patients stayed in these programs no more than 30 days. "This is one of our most surprising findings," Dr. Fletcher says. "This treatment mode had a high percentage of patients reporting daily or weekly use of cocaine in the year before treatment and a sharp decline in weekly and daily use after treatment." The percentage of patients reporting illegal acts and thoughts of suicide also declined significantly after treatment in these programs. The researchers are exploring whether continuing involvement in outpatient services and mutual help groups may have contributed to these positive outcomes.
  • In every city studied in DATOS, support services such as medical, legal, financial, psychological, employment, and family services had declined dramatically since TOPS, while the need for those services had increased. (See "DATOS Documents Dramatic Decline in Drug Abuse Treatment Services".)
  • Patients surveyed by DATOS reported that it took them about 7 years after they first used their primary drug to enter treatment. (See "Treatment Histories: The Long View of Addiction".)
The Drug Abuse Treatment Outcome Study found reductions in the use of all drugs including cocaine, heroin, and marijuana after treatment.

New Demographics

Demographic characteristics of patients studied in DATOS had changed since the earlier study. For example, DATOS patients were older and had more years of schooling than TOPS patients, and a greater percentage of them were women.

In DATOS, 39 percent of patients admitted to outpatient methadone programs were women compared to approximately 31 percent in TOPS. Women made up approximately 33 percent of the patients admitted to long-term residential programs, as opposed to 22 percent for TOPS. Outpatient drug-free programs saw little change from TOPS to DATOS, with women accounting for approximately 33 percent of patients in these programs in both studies. In DATOS, about 37 percent of patients admitted to short-term inpatient programs, which were not included in TOPS, were women. The researchers are conducting additional analyses to further explore the characteristics and outcomes for women in DATOS.

Four Common Types of Drug Abuse Treatment

Investigators with the Drug Abuse Treatment Outcome Study (DATOS) studied patients in the four most common kinds of treatment programs:

  • Outpatient methadone programs administer the medication methadone to reduce cravings for heroin and block its effects. Counseling, vocational skills development, and case management to help patients access support services are used to gradually stabilize the patients functioning. Some patients stay on methadone for long periods, while others move from methadone to abstinence.
  • Long-term residential programs offer around-the-clock, drug-free treatment in a residential community of counselors and fellow recovering addicts. Patients generally stay in these programs several months or up to a year or more. Some of these programs are referred to as therapeutic communities.
  • Outpatient drug-free programs use a wide range of approaches including problem-solving groups, specialized therapies such as insight-oriented psychotherapy, cognitive-behavioral therapy, and 12-step programs. As with long-term residential treatment programs, patients may stay in these programs for months or longer.
  • Short-term inpatient programs keep patients up to 30 days. Most of these programs focus on medical stabilization, abstinence, and lifestyle changes. Staff members are primarily medical professionals and trained counselors. Once primarily for alcohol abuse treatment, these programs expanded into drug abuse treatment in the 1980s.

Substance Abuse and Psychological Disorders

DATOS researchers looked at co-occurring psychological disorders and dependencies in 7,402 patients in the DATOS programs who were diagnosed as substance dependent. They found that 32.1 percent of those patients were dependent on cocaine alone. Of that 32.1 percent, 59.1 percent were male. Another 26.3 percent of the patients were dependent on both cocaine and alcohol, and, of those, 69.8 percent were male. In addition, 10.6 percent of the patients were dependent on heroin alone, and 64.2 percent of those were male.

The prevalence of co-occurring psychological disorders among the group was high, especially for antisocial personality disorder (APD) and major depression. APD was characterized as a pattern of disregard for the rights of others, irresponsibility, and lack of remorse. Major depression was characterized as either a depressed mood or a loss of interest or pleasure for 2 weeks or more.

When the researchers looked at retention rates, they found big differences within each of the four treatment types and among individual programs.

The prevalence of those two disorders differed widely among men and women. Approximately 40 percent of the group was diagnosed with APD, and males were twice as likely as females to be diagnosed with the disorder. While 12 percent of the group had experienced a major depression, female patients were twice as likely as male patients to have done so.

Keeping Patients in Treatment

When the researchers looked at retention rates, they found big differences within each of the four treatment types and among individual programs. "We found a lot of diversity in how well they're doing at keeping patients in treatment, and we wanted to know why," says Dr. Dwayne Simpson of Texas Christian University in Fort Worth.

The investigators found that programs with low retention rates tended to have patients with the most problems, particularly antisocial personality disorder, cocaine addiction, or alcohol dependence. In addition, heroin abusers who also abused crack cocaine but not powder cocaine had significantly lower retention rates than other heroin abusers did. "These programs are dealing with some tough people. Programs with the highest concentration of these problem patients naturally tend to have low retention," Dr. Simpson says.

What makes patients stay in treatment? The researchers found that the major predictors were:

  • high motivation;
  • legal pressure to stay in treatment;
  • no prior trouble with the law;
  • getting psychological counseling while in treatment; and
  • lack of other psychological problems, especially antisocial personality disorder.

see captionPercentage of Patients Reporting Weekly or More Frequent Substance Use Before and After Treatment Patients in programs surveyed for DATOS showed a marked reduction in drug use after treatment regardless of the type of treatment program in which they participated. DATOS analyses focused on marijuana use instead of heroin use among patients in short-term inpatient programs and outpatient drug-free programs because the number of patients using heroin in those programs was too small to allow statistical comparisons.
* Weekly or more frequent use with 5 or more drinks at a sitting.
** Outpatient methadone patients still in treatment were interviewed approximately 24 months after admission.
see captionPercentage of Patients Reporting These Behaviors Before and After Treatment. The DATOS data showed reductions after treatment in illegal acts, which included assault, robbery, burglary, larceny, forgery, and fencing; less than full-time employment; and suicidal thoughts and suicide attempts, indicators of depression.
* Outpatient methadone patients still in treatment were interviewed approximately 24 months after admission.

Lessons From DATOS

What were the overall conclusions? "Clearly there were significant changes from before to after treatment in each of the four modalities," says Dr. Fletcher. That finding raises some interesting questions, he adds. "For example, retention has been our most powerful and consistent predictor of treatment outcomes - yet even people in short-term inpatient treatment for 30 days or less improved significantly." Although DATOS replicated the finding from DARP and TOPS that time in treatment is important, the relationship to retention of other factors such as motivation, psychiatric comorbidity, and treatment process needs to be studied more, he says.

One would also expect worse outcomes from DATOS compared to TOPS because of the steady decline in availability of support services, says Dr. Fletcher. A possible explanation for the better DATOS outcomes is that although support services have decreased, core treatment services have improved. "Core services - basic treatment techniques such as drug abuse counseling, mutual-help groups, and patient participation in devising treatment plans may have improved over the past 10 years. What we're seeing may be a result of this improvement, even though availability and use of noncore support services have declined," Dr. Fletcher says.

The study's encouraging results verify the effectiveness of drug abuse treatment no matter what its form, says NIDA Director Dr. Alan I. Leshner. "The service system has changed dramatically over the last two decades. This study gives us a unique opportunity to understand the effect of those changes and to have an impact on the way treatment is delivered," Dr. Leshner says.


  • Etheridge, R.M.; Hubbard, R.L.; Anderson, J.; Craddock, S.G.; and Flynn, P.M. Treatment structure and program services in DATOS. Psychology of Addictive Behavior, in press.
  • Flynn P.M.; Craddock, S.G.; Luckey, J.W.; Hubbard, R.L.; and Dunteman, G.H. Comorbidity of antisocial personality and mood disorders among psychoactive substance-dependent treatment clients. Journal of Personality Disorders 10(1):56-67, 1996.
  • Hubbard, R.L.; Craddock, S.G.; Flynn, P.M.; Anderson, J.; and Etheridge, R.M. Overview of one-year follow-up outcomes in DATOS. Psychology of Addictive Behavior, in press.
  • Simpson, D.D.; Joe, G.W.; Broome, K.M.; Hiller, M.L.; Knight, K.; and Rowan-Szal, G.A. Program diversity and treatment retention rates in DATOS. Psychology of Addictive Behavior, in press.