RESEARCHERS, ESPECIALLY IN THE UNITED STATES, HAVE MADE PROGRESS IN UNDERSTANDING THE COMPLICATED PROCESS OF TRANSMITTING IMPULSES FROM NEURON TO NEURON THROUGH NEUROTRANSMITTERS, IN DEVELOPING SURGICAL TECHNIQUES TO PERMIT COMMUNICATION BETWEEN THE BRAIN HEMISPHERES (THUS REDUCING EPILEPTIC EFFECTS OF THE SPLIT BRAIN CONDITION), AND IN EXPLORING THE FUNCTION OF OPIATE RECEPTORS ON THE SURFACE OF CERTAIN BRAIN CELLS, AS WELL AS IN ESTABLISHING THE USEFULNESS OF MORPHOMIMETIC ENDOGENOUS PEPTIDES (ENDOMORPHINES AND ENKEPHALINES) FOR TREATMENT OF AGGRESSION AND ANGUISH. THIS RESEARCH HAS LED SCIENTISTS TO BELIEVE THAT CERTAIN KINDS OF SCHIZOPHRENIA MAY RESULT FROM IMBALANCES BETWEEN ACTIVE AND INACTIVE ENDORPHINE, THAT MELANCHOLY MAY BE THE RESULT OF A NEUROTRANSMITTER DEFICIENCY, AND THAT AGGRESSIVE BEHAVIOR IS A CONSEQUENCE OF DAMAGE TO THE FRONTAL LOBES OR TO THE PRESENCE OF TUMORS, AS NUMEROUS CASES OF VIOLENT CRIMINALS DEMONSTRATE. THE ABILITY TO DETECT CHROMOSOME ANOMALIES NOW MAKES IT POSSIBLE TO IDENTIFY PERSONS WITH POTENTIAL BEHAVIORAL PROBLEMS, ALTHOUGH CRIMINAL BEHAVIOR SHOULD NEVER BE ATTRIBUTED TO GENES ALONE, AS ENVIRONMENTAL STIMULUS MAY ALWAYS PLAY A ROLE. ATTEMPTS TO ESTABLISH A BRAIN CENTER OF AGGRESSION HAVE FOCUSED ON THE AMYGDALA. THE RESEARCH GIVES RISE TO THE HOPE THAT VIOLENT CRIMINALS CAN BE TREATED. ALTHOUGH SURGICAL METHODS HAVE IMPROVED TREATMENT POSSIBILITIES, THEY CAN BE MANIPULATED TO ENDANGER INDIVIDUAL RIGHTS AND SHOULD ONLY BE USED AS A LAST RESORT TO RELIEVE SUFFERING. PHARMACOLOGICAL TREATMENT MODES, SUCH AS MALE ANTIHORMONES FOR SEX OFFENDERS AND TRANQUILIZERS IN COMBINATION WITH PSYCHOTHERAPY, ARE MORE PROMISING, IF CONTROVERSIAL. THE NEED FOR A MULTIDISCIPLINARY APPROACH TO DEALING WITH VIOLENT CRIME IS EMPHASIZED. --IN FRENCH. (KMD)