No therapy is without risks, side effects, or even complications: this also applies to psychotherapy. Not only the effects of the therapy itself but also the interaction between therapist and patient, the behavior of the therapist, or the setting pose risks for both parties. Starting from a fundamental definition, classification, and empirical findings on psychotherapy side effects, the essential risks of various psychotherapy methods and forms are presented. The topic is addressed from the perspective of both the therapist and the patient, as both can be exposed to side effects. Concrete strategies for the prevention and reduction of risks and side effects are provided. The second updated edition of the book is evidence that the topic of psychotherapy side effects is gaining increasing interest.