THE SURVEY FORM ELICITED INFORMATION ON INMATE PERSONAL BACKGROUND, DRUG USE, AND PSYCHOLOGICAL PROBLEMS DURING DETOXIFICATION. RESULTS SHOW THAT IN THE 3 MONTH STUDY PERIOD 258 HARD DRUG USERS WERE INCARCERATED IN DETENTION CENTERS, WHICH AMOUNTS TO MORE THAN 1000 A YEAR. IN OTHER WORDS, ABOUT ONE-THIRD OF ALL HARD DRUG USERS ARRESTED BY THE POLICE ARE PLACED IN DETENTION CENTERS. THUS, AT LEAST 3,000 HARD DRUG USERS ARE INVOLVED IN CRIMINAL ACTIVITIES IN THE NETHERLANDS. MOST OF THE HARD DRUG USERS IN DETENTION CENTERS ARE HEROIN ADDICTS. THE TYPICAL HARD DRUG USER IS MALE, SINGLE, AND ABOUT 25 YEARS OLD; HE WAS USUALLY BORN IN THE NETHERLANDS OR SURINAM AND RESIDES IN AMSTERDAM, ROTTERDAM, THE HAGUE OR HAARLEM. MORE THAN 10 PERCENT OF THE DETENTION CENTER POPULATION IN HOLLAND IN 1977 WAS ADDICTED TO HARD DRUGS, BUT THIS FIGURE IS PROBABLY CONSIDERABLY HIGHER FOR SOME JAILS. THE AVERAGE INCARCERATION TIME OF HARD DRUG USERS IS 70 DAYS; AFTER THAT PERIOD 50 PERCENT ARE RELEASED AND 30 PERCENT ARE SENT TO PRISON. ON THE AVERAGE, HARD DRUG USERS IN DETENTION CENTERS HAVE ALREADY BEEN CONVICTED 10 TIMES, AND MORE THAN A THIRD WAS INVOLVED WITH THE LAW BEFORE REACHING THE AGE OF 18. THE LATTER GROUP WAS GENERALLY INVOLVED IN CRIMINAL ACTIVITIES, ESPECIALLY PROPERTY CRIMES, EVEN BEFORE THE ONSET OF DRUG USE. HARD DRUG USERS WITH CRIMINAL INVOLVEMENT PRIOR TO ADDICTION ARE MUCH MORE DIFFICULT TO REHABILITATE THAN HARD DRUG USERS WHOSE ONLY MOTIVATION FOR CRIMINAL ACTIVITY IS THEIR DRUG HABIT. THE TREATMENT FOR DRUG USERS VARIES WIDELY FROM DETENTION CENTER TO DETENTION CENTER; THREE OF NINE DETENTION CENTERS USE METHADONE TREATMENT. LESS THAN A THIRD OF THE INCARCERATED DRUG USERS HAVE RECEIVED PREVIOUS TREATMENT FOR ADDICTION. IT IS VERY DIFFICULT FOR DETENTION CENTER MEDICAL STAFF TO CONTINUE THE PREVIOUS TREATMENT; PARTICULARLY METHADONE MAINTENANCE TENDS TO BE HALTED. UPON RELEASE FROM THE DETENTION CENTER, 23 PERCENT OF THE RELEASED OFFENDERS EXPRESS THE INTENTION TO AVOID FUTURE DRUG USE, 33 PERCENT INTEND TO CONTINUE DRUG USE, AND THE WISHES OF 44 PERCENT ARE UNCLEAR. TABLES AND A SAMPLE DATA COLLECTION FORM ARE SUPPLIED.