Numerous factors can influence the processing of pain message: the affective or emotional, the sensorial and the cognitive components. Interindividual variations at the emotional and cognitive levels may interfere with the pain message and the consecutive behavior. Some modifications in these components are observed in psychiatric troubles, but their influences on the behavior to pain have not been studied, although they have been studied in some populations characterized as non communicating, with obvious cognitive degradations (subject with dementia, older, newborns,…).In an other study in course, the past pain experience is explored in relation to results to experimental pain tests, emotional and anxious characteristics. This present pilot study aims at studying the infra-verbal behavioural signs during experimentally induced pain in subjects with schizophrenia, major depression, and controls.

The objective is to search for behavioral non verbal indicators of pain during experimentally induced pain (pressure application, ischemia induction).

Included subjects are subjected to experimental pain tests : pressure application (160 kPa) with an algometer to determine the pain with Visual Analogic Scale (VAS), and ischemia induction to determine the time needed to feel pain with an intensity equivalent to 3 with the VAS.

Subjects are filmed during experimentation to identify the corporal mobility signs, facial expression signs and sonorous signs associated to pain stimulation.

Neurophysiological measures complete these observations : surface electromyogram, heart rate measure, blood pressure.

Inclusion Criteria:

• subjects with psychiatric trouble : diagnosis of schizophrenia or major depression according to the DSM-IV-TR criteria.
• control subjects : without known psychiatric history.
• age between 18 and 60.

Exclusion Criteria:

• absence of consent, hospitalization under constraint, absence of health insurance.
• inability to answer the questionnaires
• pregnancy
• antalgic or analgesic treatment
• allergy to latex
• non stabilized high blood pressure, bad blood coagulation,
• peripheral neuropathy, nerve lesion, dermatosis at the superior extremities, muscular lesion or pathology at the upper member level
• non treated alcohol dependence
• illegal substance consumption in the past 48 hours
• participation to an other biomedical study during the 2 weeks before inclusion, and until the pain tests, if this study can interfere with the realization of the objectives

subjects with major depression

12 months

no adverse event to be reported