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Treatment of Cocaine Dependence

Cocaine use is the most common drug problem of patients entering treatment for illicit drug use.  In a national sample from 55 treatment programs, problem severity of patients at admission was found to be directly related to cocaine relapse in the year following discharge, and treatment retention also was a significant predictor among moderate-to-high problem groups.  Among the highest severity patients, 90 days or longer in residential programs was needed to improve outcomes.  Findings suggest patient assessments should play a central role in the selection of appropriate settings and duration of treatment to maximize outcomes. 

One-year follow-up interviews with a national sample of 1605 patients treated for cocaine dependence in 55 programs showed (again) that longer treatment stays are related to better outcomes. Overall, 1 of 4 (24%) reported relapses to weekly cocaine use and another 18% obtained further treatment in the year after discharge in DATOS due to continuing problems. The sample included 542 from 19 long-term residential (LTR) programs, 548 from 24 outpatient drug-free (ODF) programs, and 605 from 12 short-term inpatient (STI) treatment programs.

  • Although all patients in the study met clinical criteria for cocaine dependency, not all were daily or heavy users in the year before treatment. In LTR, 49% used cocaine daily before treatment, dropping to 12% in the year afterwards. In addition, heavy drinking (3 or more days per week) dropped from 42% to 16%, and incarcerations in jail dropped from 79% to 35% in the year before versus after treatment.
  • In ODF, 28% used cocaine daily before treatment, dropping to 9% in the year afterwards. Heavy drinking (3 or more days per week) dropped from 34% to 16%, and incarcerations in jail dropped from 73% to 28%.
  • In STI, 45% used cocaine daily before treatment, dropping to 8% in the year afterwards. Heavy drinking (3 or more days per week) dropped from 45% to 15%, and incarcerations in jail dropped from 53% to 20%. (Only 33% of the STI group were unemployed on a full-time job in the year prior to admission, compared to 59% in LTR and 51% in ODF.)

Chart:  Daily Cocaine Use in Past Year:  Changes from before to after treatment       Chart:  Drinking 3+ Days/wk in Past Year:  Changes from before to after treatment       Chart:  Any Jail in Past Year:  Changes from before to after treatment


However, comparisons of relapse to weekly cocaine use rates between different types of client and treatment programs were the main focus of the study. Problem severity at intake (PSI, defined by 7 scores on drug history and psychosocial indicators) was assessed and found to differ across types of treatment programs; on average, LTR treated the most severe cases and STI the least problematic cases. PSI scores were predictive of relapse to weekly cocaine use after treatment, but different programs were not all equally effective. While low-severity patients did about equally well regardless of the type of treatment they received or how long they stayed, outcomes for medium-to-high problem patients improved significantly if they were treated for at least 3 months.

  • Problem indicators included multiple drug use (27% of the total sample), alcohol dependence (51), criminal activities (60%), unemployment at a full-time job (47%), low social support from family and friends (56%), depression or anxiety (66%), and no insurance (76%).

  • Low-level severity (0 to 3 problems) described 26% of admissions to LTR, 43% of ODF, and 64% of STI; on the other hand, 24% of LTR, 11% of ODF, and 6% of STI were high-severity patients (with 6-7 problems).
  • Overall, 20% of low-severity patients reported relapse to weekly cocaine use, regardless of whether they had short-term or long-term stays in treatment. ("Long-term" was defined as at least 90 days for LTR or ODF, and at least 21 days for STI.)

  • Among patients with medium-to-high problem severity at intake (i.e., 4 or more problems), 40% of those with short-term treatment stays relapsed to weekly cocaine use, compared to 28% of those with long-term stays.

Chart: Types of Problems at Admission     Chart: Total Number of Problems     Chart:  Weekly Cocaine Use (in Year after Treatment)

For the most severe cases (with 6-7 problems), however, treatment setting became highly significant. In particular, we found that these patients needed at least a "minimum dose" of more intensive services in LTR (usually therapeutic community) programs. After staying in one of these programs for at least 3 months, 15% relapsed in the 1-year follow-up. By comparison, relapse rates were 29% for similar patients treated in ODF settings for 3 months or longer and 38% of those treated for prescribed stays of at least 21 days in STI programs.

Chart: Weekly Cocaine Use -- High Problem Patients

The results of this study, of course, lead to many other questions about the particular treatment services involved, the therapeutic engagement process, influences of treatment history and social context, and cost benefits. These are some of the topics addressed in the next wave of DATOS articles contained in special issue of Drug and Alcohol Dependence (Simpson & Brown, eds., 1999). A report on the first national study of treatment outcomes in England is also included, which replicates many of the DATOS findings (see the NTORS Web site at www.ntors.org.uk for more details.)


Simpson, D., Joe, G., Fletcher, B., Hubbard, R., & Anglin, D. (1999). A national evaluation of treatment outcomes for cocaine dependence. Archives of General Psychiatry, 56, 507-514.   [Abstract]

Simpson, D. & Brown, B. (Eds). (1999). Special issue on treatment process and outcome studies from DATOS. Drug and Alcohol Dependence.  [Summary]

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Last Revised:
14 December 2001

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