To review the scientific and empirical evidence that is usually accepted for the ethical and legal justification of coercion in psychiatry. Five key criteria are examined as follows: (1) the demonstrable existence of a mental disorder; (2) the effectiveness of psychiatric measures; (3) the use of coercion as last resort and as least possible restriction; (4) the benefit of the person affected by the coercive measure and (5) the restoration of the affected person's autonomy. (1) The existence of a demarcation between a mentally ill and a mentally healthy state cannot be confirmed; (2) Pharmacological and psychotherapeutic interventions in psychiatry are not even moderately effective; (3) Coercive measures are usually not used as last resort and as least restrictive measure; (4) Most people affected by psychiatric coercion do not benefit from the measures; (5) It is at least unclear whether autonomy is affected by a mental illness and whether it can be restored through a coercive psychiatric measure. None of the central ethical and legal criteria for the use of coercion in psychiatry are clearly and unambiguously fulfilled according to current research. Psychiatric coercion can hardly be justified any longer.