Investigation of Neurophysiological Markers, Possibly Specific of Two Subforms of Psychotic Disorders

Investigation of Clinical, Cognitive and Neurophysiological Markers, Possibly Specific of Two Subforms of Psychotic Disorders

The current diagnostic criteria for schizophrenia and other psychotic disorders are relatively broad and lack precision. Therefore, distinct diseases may be grouped together under the same diagnostic category, although these diseases may differ according to their clinical expression, prognosis and perhaps their physiopathological causes.

We think that identifying subforms of psychotic disorders that are more homogeneous will better enable to understand their respective physiopathological causes and find personalized treatments.

This study will compare two subforms of psychotic disorders that have been clinically distinguished in the 1970s. These phenotypes have however not been validated yet using scientific investigations.

Using clinical assessments, cognitive evaluations and neurophysiological measures (fMRI) investigating the domains of affect and psychomotoricity , we expect that these two subforms will differ on their clinical, cognitive and neurophysiological characteristics, namely: hebephrenia will be associated with deficits on the affect markers , and respect psychomotoricity (catatonia scales, tests assessing movement planification) whereas the opposite pattern will be observed for periodic catatonia.

Inclusion Criteria:

• for both patients and controls
• male or female willing to participate and who have signed up the legal document
• under the protection of health insurance for patients only
• schizophrenia or schizo-affective disorder according to the DSM-5 criteria
• periodic catatonia or hebephrenia accordin to WKL classification
• clinically stable for at least 2 months
• in or out patients for controls only
• no psychiatric history

Exclusion Criteria:

• for both patients and controls
• current severe or unstable somatic illness
• neurological history (epilepsia, brain injury, brain surgery…)
• current substance use disorder (DSM-5)
• current major depressive disorder (DSM-5)
• mental retardation (IQ < 70)
• pregnancy, breast feeding
• current legal control
• contra-indication for fMRI for controls only psychotropic intake during the last 3 weeks