Prof. Dr. Jan Derksen is a clinical psychologist and psychotherapist. He is involved in the post-doctoral education in psycho-diagnostics for psychologists and psychotherapists. He has been teaching as head educator psycho-diagnostics at the Radboud University Nijmegen and he is emeritus Professor clinical psychology at the VU in Brussels. He started a publishing house for psychological test materials. Derksen has published multiple books on narcissism, psycho-diagnostics and the relation between neuroscience and psychology.