Existential Psychotherapy is a book about existential psychotherapy by the American psychiatrist Irvin D. Yalom, in which the author, addressing clinical practitioners, offers a brief and pragmatic introduction to European existential philosophy, as well as to existential approaches to psychotherapy. He presents his four ultimate concerns of life—death, freedom, isolation, and meaninglessness—and discusses developmental changes, psychopathology and psychotherapeutic strategies with regard to these four concerns.