Abuse of psychiatry was in the Soviet Union, for several decades, a State policy to quell dissent, and was carried out in collaboration with the then leadership of Soviet psychiatry. Approximately one-third of all political prisoners were subjected to this practice. The Soviet case has been taken as the main example. However, this branch of medicine has been misused elsewhere, in particular, in the Eastern Bloc in the 1980s, and in the People’s Republic of China in the late 1990s. Before World War II, on the pretext of setting up a merciful euthanasia programme, the Nazi regime made medical and nursing staff kill, by injection and gassing, tens of thousands of patients suffering from an incurable physical or mental illness. The chapter ends with thoughts on how the political abuse of psychiatry can be prevented.