THERE IS A BRIEF DISCUSSION CONCERNING THE POTENTIAL FOR EXISTING TREATMENT PROGRAMS FOR CHRONIC HEROIN USERS TO REDUCE THEIR DEMAND FOR ILLICIT DRUGS. THE PRESENT STUDY WAS UNDERTAKEN TO PROVIDE DATA ON THE OUTCOMES OF PERSONS WITH HISTORIES OF CHRONIC DAILY NARCOTICS ADDICTION, WHO ENTERED METHADONE MAINTENANCE PROGRAMS IN NEW YORK CITY AND WERE DETOXIFIED AFTER VARIOUS PERIODS OF TIME. THE INITIAL PHASE OF THE STUDY, WHICH IS THE SUBJECT OF THIS REPORT, DEALT WITH A RANDOM SAMPLE OF 461 PATIENTS DRAWN FROM A LISTING OF 5,571 PERSONS WHO ENTERED TREATMENT IN THE CALENDAR YEAR 1972 AND WERE NOT IN TREATMENT DURING THE FIRST SIX MONTHS OF 1974. FOR COMPARISON, AN EQUAL SAMPLE MATCHED BY AGE, SEX, AND ETHNIC GROUP WAS DRAWN FROM THE 11,994 PERSONS WHO ENTERED TREATMENT DURING THE SAME YEAR BUT REMAINED IN TREATMENT. ALTHOUGH THE FOLLOWUP STUDY WAS NOT COMPLETED AT THE TIME OF WRITING, THE DIFFERENCES IN OUTCOMES BETWEEN THE TWO GROUPS IS BELIEVED TO BE LARGE ENOUGH TO JUSTIFY THIS PRELIMINARY REPORT. DATA ARE PROVIDED TO SHOW THE OUTCOMES OF 202 SUBJECTS WHOSE TREATMENT WAS TERMINATED CLASSIFIED BY TIME OF PRETREATMENT ADDICTION, TIME IN TREATMENT, AND TIME AFTER TREATMENT. OVER 89 PERCENT OF THE SAMPLE HAD EITHER RELAPSED TO NARCOTICS USE, BECOME ALCOHOLIC, USED OTHER DRUGS TO A DISABLING DEGREE, OR WERE ARRESTED OR DIED WITHIN 2 YEARS OF TERMINATION. ON THE OTHER HAND, 53 PERCENT OF THE COMPARISON GROUP WAS FOUND TO HAVE NO DRUG OR LEGAL PROBLEMS UNDER MORE RIGID CONDITIONS OF SCRUTINY, SINCE THESE PERSONS CAME TO THE CLINIC FOR MEDICATION TWO OR MORE TIMES PER WEEK AND WERE SUBJECTED TO REGULAR URINALYSIS. FINDINGS OF THIS STUDY ARE COMPARED WITH THOSE OF OTHER SIMILAR STUDIES. NO STUDY FOUND THAT ANY SIZABLE GROUP OF PERSONS WITH A HISTORY OF CONTINUOUS DAILY USE OF HEROIN FOR A PERIOD OF 2 OR MORE YEARS PRIOR TO TREATMENT HAVE REMAINED DRUG-FREE FOR AS LONG AS 1 YEAR FOLLOWING TERMINATION OF MAINTENANCE. IT IS CONCLUDED THAT UNTIL SUCH EVIDENCE IS AVAILABLE, IT DOES NOT SEEM REASONABLE TO PROCEED ON THE ASSUMPTION THAT THE MAJORITY OF THE DAILY USERS OF HEROIN CAN BE CURED BY A LIMITED PERIOD OF METHADONE MAINTENANCE FOLLOWED BY DETOXIFICATION. (RCB)