Epidemiological studies show that one person in eight suffers from at least one psychiatric disorder. Mental health is therefore a major public health issue, and care for these disorders must continue to be improved.

The management of mental disorders has long followed the traditional categorical approach of developing a treatment for a given disorder. However, researchers have recently pointed out the limits of this approach in the field of mental health. They highlight the large number of co-morbidities, the existence of aspecific disorders and the intra-diagnostic heterogeneity of patients. These factors have led them to develop a transdiagnostic approach, which focuses on the mechanisms common to the various disorders in order to treat them at the same time and thus reduce the cost of treatment.

Inclusion Criteria:

• Male or female ≥ 18 years of age
• Have at least one diagnosis of a psychiatric disorder
• Be able to carry out psychotherapy sessions
• Have been on stable psychiatric medication for 30 days
• Written informed consent obtained from the participant
• Be affiliated to a social security scheme or equivalent

Exclusion Criteria:

• Cognitive deficits marked by a score above the 10th percentile for one or more tests in the assessment history.
• Persons deprived of liberty by judicial or administrative decision; Persons under legal protection: guardianship or curatorship
• Presence of a severe depressive episode
• Be engaged in psychotherapeutic work elsewhere
• Presence of a state of excessive deficit, making psychotherapy impossible
• Presence of psychic decompensation (e.g. delusions) making psychotherapy impossible