French Minds Cohort: a French Longitudinal and Multimodal Cohort of Patients With Major Mood Disorders, Psychotic Disorders, Autism Spectrum Disorders, and Healthy Controls

The goal of this study is to learn whether people living with severe psychiatric disorders can be grouped into more homogeneous subgroups, across usual diagnostic categories, based on two key dimensions: social withdrawal and anhedonia (reduced ability to feel pleasure). The study includes adolescents and adults aged 15 to 60 with schizophrenia, a first psychotic episode, bipolar disorder, recurrent or treatment-resistant major depressive disorder, or autism spectrum disorder without intellectual disability, as well as healthy volunteers aged 18 to 60. The main questions it aims to answer are: * Can subgroups of patients sharing a common profile of social withdrawal and anhedonia be identified, with similar clinical, genetic, biological and brain imaging characteristics? * Do other dimensions (cognitive flexibility, neurodevelopmental, sensory and sleep disturbances, impulsivity) and specific clinical forms (e.g., autoimmune psychosis, metabolic abnormalities) define relevant subgroups, and how do these subgroups evolve over time? Researchers will compare patients with healthy volunteers to identify clinical and biological signatures specific to each subgroup. Participants will: * Attend an inclusion visit, two one-day assessment visits one year apart (clinical interviews, questionnaires, cognitive tests, fasting blood sample) and two brain MRI sessions * Optionally provide a stool sample collected at home * Complete questionnaires on a smartphone app and wear a connected watch (activity, sleep, heart rate) between visits * Take part in the study for about 18 months French Minds is conducted in about 35 centres in France and aims to include 2,500 patients and 500 healthy volunteers.