Introduction DSM is a psychiatric classification, founded and developed by the American Psychiatric Association. It is used worldwide in the scientific communities and known by the general population throughout the world. Over the years, it has received much appreciation as well as much criticism. So far known, it’s the first psychiatric classification that so profoundly influences society. It’s also known as the Bible of psychiatry and defined as the cookery book of psychiatry as well. Cheering sky high and deeply saddened. What is it all about? This international colloquium is an attempt to establish an honest assessment of the use of the DSM-5 in the field of psychiatry and mental health (research, epidemiology, teaching, clinical, medico-economics, improvement of public mental health, public policy in mental health). It’s also an event to break down the barriers between different approaches to mental disorders and enable people to meet in a setting where the ethics of discussion will be preserved. As ‘colloquium’ etymologically means ‘a speaking together’, round tables form the main part of the colloquies. Combined with oral presentations and Q&A, du choc des idées jaillit la lumière, the clash of ideas gives rise to light.