This Classic Edition of On the Theory and Therapy of Mental Disorders: An Introduction to Logotherapy and Existential Analysis sees Viktor E. Frankl, bestselling author and founder of logotherapy, introduce his key theories and apply them to work with patients exhibiting symptoms of neurosis. James M. DuBois’ translation of Frankl’s Theorie und Therapie der Neurosen allows English readers to experience this essential text on logotherapy in an invigorating new light.