THE FULL OUTCOME AND SUMMARY REPORT OF THE DRUG ABUSE TREATMENT OUTCOME STUDY (DATOS) COVERS AN EVALUATION OF DRUG ABUSE TREATMENT PROGRAMS WHICH WERE NOT RUN BY CRIMINAL JUSTICE AGENCIES. THE STUDY WAS TO COMPARE SIX TREATMENT MODALITIES AND THE PUNISHMENT MODALITY, USING CLIENT CONTACTS WITH A STUDY POPULATION OF CLIENTS ENTERED DURING THE SECOND QUARTER OF 1975 AND DISCHARGED BY THE END OF 1975 (EXCEPT FOR OUTPATIENT METHADONE MAINTENANCE). THE NUMBER OF DISCHARGED PATIENTS WHO COULD BE FOUND WAS SMALLER THAN THE 1,200 SOUGHT. CONSEQUENTLY THE SCOPE OF THE STUDY WAS NARROWED TO OUTPATIENT METHADONE MAINTENANCE AND INPATIENT DETOXIFICATION FOR HEROIN USERS AND RESIDENTIAL DRUG-FREE TREATMENT AND INPATIENT DETOXIFICATION FOR NONHEROIN USERS. UNLESS INTANGIBLE BENEFITS ARE COUNTED, SUCH AS TIME SPENT WITH FAMILY, THE COST-EFFECTIVENESS OF ALL OF THE PROGRAMS IS NOT VERY GREAT. METHADONE WAS SUPERIOR TO DETOXIFICATION FOR HEROIN USERS BUT, OTHER THINGS BEING EQUAL, LOW-COST HEROIN MAINTENANCE MIGHT HAVE BEEN EVEN BETTER BY THE CRITERIA USED. LITTLE DIFFERENCE BETWEEN MODALITIES WAS FOUND FOR THE NONHEROIN USERS. A MORE THOROUGH STUDY IS RECOMMENDED, WITH BETTER ACCESS TO OFFICIAL CRIMINAL RECORD HISTORIES AND WITH FINANCIAL REIMBURSEMENTS TO COVER THE VERY SUBSTANTIAL ONE-SHOT EFFORTS REQUIRED BY AGENCIES TO PROVIDE DATA FOR THE BUDGET MANAGEMENT STUDIES. A COMPARISON OF INPATIENT AND OUTPATIENT DETOXIFICATION IS RECOMMENDED. IT IS POSSIBLE THAT TREATMENT DID HAVE A SUBSTANTIAL IMPACT UPON EMPLOYMENT FOR SUBGROUPS OF PEOPLE, AND ADDITIONAL RESEARCH TO SUBSTANTIATE THIS IS RECOMMENDED. TABLES, A BIBLIOGRAPHY, FIGURES, CHARTS, AND APPENDIXES CONCERNING METHODOLOGY ARE INCLUDED. (TWB)