[New neuroleptic agents and new models for psychoses]

Atypical neuroleptics can be defined as dopamine receptor blockers which differ from typical neuroleptics in that they have a markedly lower or absent propensity for the induction of parkinsonian side effects or tardive dyskinesias. The authors are studying varied molecules considering their mechanism of action. The differences between atypical and typical neuroleptics may relate to regional specificity in site of actions and receptor binding profile. The authors insist on clozapine, which is a D2 antagonist and in which many other systems might be involved. New neural models may help understand these interactions. The Swerdlow and Koob's model is a unified hypothesis of cortico-striato-pallido-thalamic function which can explain psychoses, depression, dyskinesias and Parkinsonian disorders. The authors make a linkage between this model and Davis's hypothesis. This author hypothesizes that schizophrenia is characterized by abnormally low prefrontal dopamine activity leading to excessive dopamine activity in mesolimbic dopamine neurons, that explains the both negative and positive symptoms coexistence. For the authors, new ways are then opened for an integrative conception of psychosis and affective disorders. This conception might be integrated into the bio-psycho-social model based on chaotics, evocation of which is the author's conclusion.