ACCORDING TO BELGIUM'S SOCIAL DEFENSE LAW OF 1930, INTERMEDIATE MENTAL PROBLEMS WERE TO BE TREATED IN A SPECIAL PRISON SETTING UNDER THE SUPERVISION OF A PSYCHIATRIST; THE SYSTEM PROVED WORSE THAN REGULAR PRISONS, AS SENTENCES WERE OF INDETERMINATE LENGTH. POST-WAR REFORMS PROVIDED FOR PRISONERS' PSYCHOLOGICAL EXAMINATIONS, AND SINCE THEN PSYCHOLOGICAL SERVICES HAVE BEEN GRADUALLY EXPANDED AND PRISON CONDITIONS HUMANIZED. FROM THE PSYCHIATRIC STANDPOINT ADJUSTMENTS HAVE BEEN MADE IN NOTIONS OF NORMALITY, AND INMATES ARE LIKELY TO DEMAND TREATMENT. ATTEMPTS TO MEET THE GROWING PSYCHIATRIC NEEDS HAVE CREATED GIGANTIC PSYCHIATRIC PRISONS, E.G., IN GREAT BRITAIN. AN ALTERNATIVE DEVELOPED IN FRANCE TO AVOID SUCH MASS INSTITUTIONS ARE REGIONAL MEDICAL-PSYCHOLOGICAL CENTERS IN PRISONS STAFFED WITH A PSYCHIATRIST PRESENT ON A DAILY BASIS, A PSYCHIATRIC NURSE, AND CORRECTIONAL OFFICERS WITH TRAINING IN TREATMENT. SUCH CENTERS ARE LOCATED AT THE HEART OF PRISONS AND REQUIRE OUTSIDE TELEPHONE LINES. THE CENTERS STRESS INMATE PARTICIPATION IN TREATMENT, CONCERTED EFFORTS AMONG AUTHORITIES INVOLVED, AVOIDANCE OF MEDICATION OVERUSE AS WELL AS OF EXCESSIVE PSYCHIATRIC INTERPRETATION OF CRIMINAL BEHAVIOR, AND THE NEED FOR CONFERENCES ATTENDED BY MEMBERS OF DIFFERENT MEDICAL-PSYCHOLOGICAL CENTER STAFFS. EMERGENCY SERVICES IN HOSPITAL CENTERS AND REDESIGNED HOSPITAL CENTERS SHOULD ALSO SERVE THE PRISON POPULATION. THE IMPORTANCE OF THE PSYCHIATRIC TEAM'S INDEPENDENCE FROM PENITENTIARY AND JUDICIAL CONTROL IS EMPHASIZED. --IN FRENCH. (KMD)