Self-stigma refers to the transformation process wherein a person's previously held social identity is progressively replaced by a devalued and stigmatized view of oneself termed "illness identity". Self-Stigma is a severe problem in Serious Mental Illness (SMI). Self-stigma prevalence is high (41.7% of the 1229 participants with SZ and 21.7% of the 1182 participants with mood disorders had moderate to high levels of IS in the GAMIAN-Europe study). Self-stigma was negatively associated with self-esteem, social function, wellbeing, quality of life or personal recovery and positively associated with psychiatric symptoms and depression. Several psychosocial interventions (mostly combinations of psychoeducation and cognitive behaviour therapy) have been designed to reduce self-stigma and its impact on clinical and functional outcomes, with preliminary effects on self-stigma, insight and self-efficacy.

Narrative Enhancement and Cognitive Therapy (NECT) is a manualized structured 20-session group-based intervention . Conducted by two trained facilitators the sessions combine psychoeducation, cognitive restructuring and story-telling exercises to reduce self-stigma. Developed in USA, NECT was adapted in Israel and Sweden. NECT showed effectiveness in reducing self-stigma and in improving self-esteem and quality of life. Despite being effective on changing coping strategies, NECT effectiveness on social function is still unclear.

The present study aims to validate NECT French adaptation and to evaluate its effectiveness on social function, self-stigma, psychiatric symptoms, self-esteem, wellbeing, quality of life and personal recovery in SMI participants (schizophrenia, bipolar disorder, borderline personality disorder)

Inclusion Criteria:

• Diagnosis of schizophrenia, schizoaffective disorder, schizotypal disorder, schizophreniform disorder, bipolar I or II disorder, borderline personality disorder (DSM-V criteria, APA, 2013).
• Clinical stability since 3 months (total PANSS score <120, MADRS score <15 and YMRS <12 for patients with schizophrenia and MADRS score <15 and YMRS <12 for patients with bipolar disorder).
• Patients who gave informed consent to participate in the study.
• Affiliated to a social security scheme or beneficiary of such a scheme.

Exclusion Criteria:

• Pregnant or lactating women.
• Criteria relating to the associated pathologies entailing particular risks:
• Neurological disorders of vascular, infectious or neurodegenerative origin.
• Taking somatic drugs with a cerebral or mental impact (eg corticosteroids).
• Presence of an associated intellectual disability.
• Prohibited treatments and procedures:
• Subject in exclusion period of another study.
• Simultaneous participation in other programs having an impact on social functioning or self-stigmatization: remediation of social cognition, individual and group care targeting self-stigmatization and training in social skills.