Cost-utility Study of Cognitive-behavioral Management of Auditory Hallucinations in Schizophrenic Disorder

The aim of the study is to assess the effectiveness and costs of a cognitive-behavioral treatment (CBT) for auditory hallucinations (psychotherapy) as an adjunct to usual care, comparing it to the effectiveness and costs of usual care alone. Usual care is defined as the use of medication, regular consultations with your psychiatrist, and, if necessary, day hospital care.

The study plans to include 240 participants across several hospitals in France (multicenter study). Each participant will be randomly assigned to either the intervention group (cognitive-behavioral therapy) or the control group (usual treatment). Participants assigned to the control group will have the opportunity to receive therapy for auditory verbal hallucinations (AVHs) after the study.

After an initial inclusion assessment (V0), the participant will be randomly assigned to one of the two groups after the V1 assessment. Additional evaluations will be conducted after inclusion at 4 months, 8 months, and 12 months.The evaluations consist of questionnaires to assess intensity and severity of AVHs / beliefs related to AVHs, clinical status, well-being, depression, suicidal thoughts, quality of life, functioning (mobility/autonomy/pain, etc.), sleep and costs related to care.

At Visit 1, after obtaining consent for participation in the study on behalf of your ward, the investigator will also collect their social security number, full date of birth, and gender, which will allow us to gather information on actual healthcare consumption from the healthcare system.

The VOICES intervention will consist of 16 one-hour individual sessions (one session per week over a 16-week period), divided into several types of intervention (modules) that have been independently proven to treat AVHs. The VOICES intervention is modular, personalized, and incorporates patient preference. Following an initial clinical assessment, patients will be offered first the GIVE intervention (8 sessions) and subsequently a choice of treatment modules, delivered by a clinical psychologist.

After this first module (GiVE Intervention), three other intervention modules will be proposed. These three additional modules comprise seven sessions each. One additional relapse prevention sessions will be scheduled at the end of these modules.

• The GiVE intervention is divided into five modules: (1) Coping - exploring ways to manage voices; (2) Me - targeting negative beliefs about the self; (3) My Voices - targeting unhelpful beliefs about voices; (4) My Relationships - improving assertiveness in difficult relationships; and (5) Looking to the Future - making plans to continue the use of new skills. Modules 2, 3 and 4 were each offered over two sessions (six sessions in total), and modules 1 and 5 were each one session long.

After the GivE intervention three modules will be offered will be :

• "Relating CBT" is based on a large body of research which has shown that voice hearers personify their voices and establish relationships with them, which largely correspond to the relationships they generally establish with the people around them. The aim of relational therapy will be to modify this relationship and enable the voice hearer to develop assertive and balanced behaviours towards them.

• The individual "Mindfulness Program for Voices" will be delivered individually and will include guided mindfulness exercises, complemented by discussions aimed at cultivating mindful responses as alternatives to automatic or habitual reactions.

• Imagery rescripting for distressing voices will consist of a series of targeted imagery-based interventions guided by a micro-formulation approach. This method will focus on the identification and transformation of discrete, emotionally salient mental images linked to specif distressing experiences

All participants will receive medical monitoring, and the treatment will be the same in both groups. No treatment will be prohibited if deemed necessary for your health. At any time, participants have the right to withdraw their consent and stop participating in the research, without any change to their care, as long as the patient's condition does not require otherwise.

The expected benefits for participants are a significant improvement in the symptoms as well as psychosocial functioning, leading to greater autonomy in daily life and an improved quality of life. In the control group, the follow-up will likely be more attentive than usual, with regular evaluations. In any case, there is no loss of opportunity for the participant regardless of the group assignment. Additionally, random assignment to the control group allows participants to benefit from AVH therapy after the study.

When the research is completed, participants will be informed of the overall results by the investigator as soon as they are available, if wished.

Participation in this research will not incur any additional costs compared to the usual follow-up for this condition.