Gender Differences in Social Cognition in Patients With Schizophrenia of Recent Diagnosis and Healthy Controls Subjects

Individuals with schizophrenia have important and persistent deficits in multiple neurocognitive domains as well as in the Social Cognition (SC). SC refers to the mental operations underlying social behavior, and it is understood as a multidimensional construct that comprises emotional processing (EP), social perspective and knowledge, attributional bias and theory of mind (ToM) or mentalizing. Mentalizing and EP skills have been the two most studied subdomains of SC in schizophrenia. Both domains have been found to be impaired in chronic schizophrenia patients as well as in patients in early stages of the illness. In this context, although negative symptoms may play and important role, females seem to perform better than males in ToM and EP tasks, suggesting the presence of gender differences in the SC skills in patients with schizophrenia. However, to our knowledge, there are no studies that have explored the gender-related differences between cognitive and affective ToM and its relationship with the EP performance in schizophrenia patients of recent diagnosis comparing with healthy subjects.

In this line, the main objective of this project is to analyze the influence of gender in the cognitive and affective ToM abilities, in a group of patients with schizophrenia in early stages of the illness comparing with healthy subjects. Secondarily, this study pretends to explore the association between EP skills and affective ToM tasks performance in males and females with and without recent diagnosis of schizophrenia.

50 patients (25 men and 25 women) will be recruited to participate in the study. Diagnosis of schizophrenia or schizoaffective disorder will be obtained through the medical records of each patient, and confirmed with the administration of the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) (American Psychiatric Association, 1994) by an expert psychiatrist. The same professional will confirm the inclusion and exclusion criteria, and administrate and correct the Positive and Negative Syndrome Scale (PANNS) of all patients. An expert neuropsychologist will administrate and correct the the abbreviated form of the Wechsler Adult Intelligence Scale (WAIS-III) and the ToM and EP tasks.

In a second phase, a total of 50 healthy people (25 men and 25 women), matched according to age and years of schooling with the previous group, will be recruited. An expert neuropsychologist will confirm the inclusion and exclusion criteria, and administrate and correct the Vocabulary subtests of the WAIS-III and ToM and EP tasks.

All of them will be informed about the characteristics of the study before participating, and will sign an informed consent approved by the ethical committee of the hospital. The subjects will participate voluntarily.

4 groups ANOVAs will be performed for studying differences in affective and cognitive ToM between the groups (1-Women With Recent Diagnosis of Schizophrenia; 2-Men With Recent Diagnosis of Schizophrenia; 3-Healthy Women; 4-Healthy Men). Linear regression models will be performed for exploring the relationship between gender, negative symptoms (only in the schizophrenia sample) and EP (independents variables) in affective ToM (dependent variable).

Eligibility Criteria:
PARTICIPANTS WITH SCHIZOPHRENIA

Inclusion Criteria:

* Patients meeting DSM-IV criteria for schizophrenia or schizoaffective disorder with less than 5 years of evolution of the disorder.
* Being an outpatient for at least 4 weeks before the study (clinical stability).
* No changes in the antipsychotic medication during the month before the study.
* Score less than 4 in the P1, P2 and P3 items of the PANSS.
* Score less than 4 in the Calgary Depression Scale.

Exclusion Criteria:

* Intellectual disability (IQ\<70).
* History of brain damage.
* History of substance abuse (except nicotine or caffeine) during the last 12 months before the study.

PARTICIPANTS WITHOUT SCHIZOPHRENIA

Inclusion Criteria:

• Healthy people over 18 years old.

Exclusion Criteria:

* Sensory impairment: visual or hearing disabilities.
* Intellectual disability (IQ\<70).
* History of neurologic disease.
* History of psychiatric disorder.
* History of substance abuse (except nicotine or caffeine) during the last 12 months before the study.