THE SUBJECT OF INVESTIGATION WAS THE CAMARILLO STATE HOSPITAL DRUG ABUSE TREATMENT PROGRAM IN CAMARILLO, CALIF. THE PROGRAM BEGAN IN 1969 AND WAS DIVIDED INTO TWO UNITS IN LATE 1970: A LONG TERM UNIT APPROACH OF 10 TO 12 MONTHS AND A SHORT TERM UNIT APPROACH OF 90 DAYS. IN 1973, THE PROGRAM WAS FURTHER DIVIDED TO INCLUDE A DETOXIFICATION UNIT. THE TWO DRUG TREATMENT UNITS DEVELOPED INDEPENDENTLY OF ONE ANOTHER. THE THERAPY AND PRINCIPLES OF THE TWO PROGRAMS WERE BASICALLY THE SAME, WITH EACH EMPHASIZING DISCIPLINE, ENCOUNTER-TYPE THERAPY, AND PEER PRESSURE. THE HOSPITAL STAFF PARTICIPATED IN THE ORGANIZATION AND OPERATION OF THE SHORT TERM PROGRAM, WHILE THE LONG TERM PROGRAM WAS PATIENT-RUN, WITH SENIOR MEMBERS BEING IN CHARGE OF ITS ORGANIZATION. CONVICTION RATES OF A SAMPLE HAVING UNDERGONE TREATMENT IN THE TWO PROGRAMS WERE EXAMINED TO DETERMINE EFFECTIVENESS. THE 267 PEOPLE CHOSEN FOR FOLLOWUP CONSISTED OF: (1) ALL PEOPLE WHO COMPLETED THE SHORT TERM PROGRAM FROM OCTOBER 1, 1971, THROUGH MARCH 26, 1973, AND (2) ALL THE GRADUATES AND 'SPLITEES' WHO LEFT THE LONG TERM PROGRAM BEFORE GRADUATION BETWEEN APRIL 1, 1971, AND MARCH 26, 1973. CONVICTION RECORDS WERE OBTAINED FOR 75.3 PERCENT OF THE 267 PEOPLE INVESTIGATED. COST EFFECTIVENESS WAS CALCULATED FOR BOTH PROGRAMS ON THE BASIS OF RATES OF COMPLETION, SUCCESS, AND FAILURE IN RELATION TO THE COSTS OF OPERATING THE PROGRAMS. THE COST TO SOCIETY OF THE CRIME COMMITTED BY THE FAILURES BEFORE REENTERING THE PROGRAMS WAS DETERMINED ALSO. THE LONG TERM PROGRAM WAS FOUND TO BE MORE EFFECTIVE AND LESS COSTLY IN THE LONG RUN. THE LONG TERM PROGRAM PROVED MOST EFFECTIVE FOR HIGHLY MOTIVATED CLIENTS, WHILE THE SHORT TERM PROGRAM PROVIDED AN EFFECTIVE ALTERNATIVE TO INVOLVEMENT WITH THE CRIMINAL JUSTICE SYSTEM FOR LESS MOTIVATED CLIENTS. DATA FROM THE STUDY ARE PROVIDED. (RCB)