[Biological approaches to acute psychoses]

According to the ICD 10 only acute psychotic disorders and transitory acute disorders are specified, whereas DSM IV index, in the same class, schizophreniform disorder, schizoaffectif disorder and atypical psychosis. State biological markers of these disorders are present during the acute episode and disappear with it. A few studies concerns trait predispositional markers of these acute psychotic disorders. In addition, several studies of acute psychotic states are indexed as a partition of usual schizophrenic disorder, as a simple occurrence of that chronic disease. From the biological point of view, dysfunctions of norepinephrine and dopaminergic metabolisms are reported within these acute schizophrenic disorganisation, especially hyperdopaminergia, causality, consequence or evidence of the state syndrome. Those kinds of data are also reported in mood disorder with delusional symptoms. A hypothetic dysregulation of the balance between oxydation and antioxydation system has been searched in these acute states of schizophrenia. From the electrophysiologic perspective, no abnormalities are found for ocular movement functions during these acute psychotic disorders. Besides the clouding of consciousness of confusional states, neuropsychological abnormalities are reported: attention disorders, lack of inhibition of non relevant informations, abnormalities of working memory. Brain imaging can substantiate a diminution of the caudate nucleus size and a possible increase of D2 receptors number. Also, in these acute psychotic states abnormalities of humoral and cellular immunologic system have been found. Lastly, street drugs can originate confusional states and depersonalization, through their serotoninergic, dopaminergic and anticholinergic properties. Ethical drugs can also create an acute psychosis disorder: individual vulnerability and somatic disease cooccurrence act as risk-factors.