This study focuses on the difficulties of maintaining optimal psychological health and quality of life for caregivers in adult psychiatry while they play an important role in helping patients with severe psychiatric disorders. It evaluates the addition of a 5 session psychological program, named Ensemble. Half of the participants will receive their usual support and Ensemble in combination, while the other half will receive usual support only.

The recent statistics showed that mental disorders affect one in four people in the world. In this context, informal caregivers are key actors in the health care system through their support. This support can be associated with very high burden and distress. Informal caregivers can experience serious situations with potential negative consequences on their quality of life, their own health and the health of patients. Data recommended to intervene at the onset of disease to improve the impact of an intervention. It seems important also to intervene while the patient is in an acute phase of illness to better support informal caregivers' emotional needs. In addition, providing emotional support for informal caregivers at the beginning of an illness in particular is recommended because this is a critical phase. The experience of painful emotions, such as denial of disease and feelings of being overwhelmed or shocked can have serious consequences on their health and on the patient's recovery. Previous studies identified that informal caregivers need tailored knowledge about the patient's illness, clarification about their roles and responsibilities, better control over their own life and effective collaboration with health professionals. Most of the interventions published in the literature focus on the ill family member and its support but not on the specific needs of the informal caregivers as the core intervention. To reduce the gap between scientific recommendations and actual practice, the investigators developed, tailored and tested a new intervention called Ensemble.

Ensemble is a brief individualized intervention designed to promote the well-being of informal caregivers who experience the effects of patients' psychiatric disorders. The five-session Ensemble program provided to informal caregivers targeted support to address their specific unmet needs, emotions and social resources. A professional addressed this programme to the informal caregiver delivered independently of the patient's treatment.

Ensemble assesses the needs of informal caregivers and provides a tailored brief support. Results of a pilot study showed that psychological health and optimism of informal caregivers were improved. For these reasons, there is a clear research and clinical need to establish whether Ensemble programme is clinically effective by using a randomized, controlled, and assessor-blind trial. A combination of Ensemble plus support as usual (SAU) will be compared to SAU alone. Informal caregivers of individuals suffering from mental disorders will undergo either intervention for five sessions, during a six weeks average time. Measure will assess participants' current psychological health state and optimism. These different measures will be performed at the time of inclusion, at the end of the intervention, and at two months follow-up. At the end of the program, individual qualitative structured interviews will be performed to assess acceptability of the programme.

Inclusion Criteria:

• Being at least 18 years old
• Living in the French-speaking cantons of Switzerland (commonly referred to as "Romandy")
• Speaking French
• Having an adult relative suffering from a psychiatric disorder (with or without an established diagnosis)
• Having the capacity to agree to participate in the project

Exclusion Criteria:

- Having les than 20 on the Zarit score.