Persecution of dissidents in the Soviet Union

There was systematic political abuse of psychiatry in the Soviet Union, based on the interpretation of political opposition or dissent as a psychiatric problem. It was called "psychopathological mechanisms" of dissent.

Throughout the history of the Soviet Union, tens of millions of people suffered political repression, which was an instrument of the state since the October Revolution. It culminated during the Stalin era, then declined, but it continued to exist during the "Khrushchev Thaw", followed by increased persecution of Soviet dissidents during the Brezhnev era, and it did not cease to exist until late in Mikhail Gorbachev's rule when it was ended in keeping with his policies of glasnost and perestroika.

The Gulag was a system of forced labor camps in the Soviet Union. The word Gulag originally referred only to the division of the Soviet secret police that was in charge of running the forced labor camps from the 1930s to the early 1950s during Joseph Stalin's rule, but in English literature the term is popularly used for the system of forced labor throughout the Soviet era. The abbreviation GULAG (ГУЛАГ) stands for "Гла́вное Управле́ние исправи́тельно-трудовы́х ЛАГере́й" (Main Directorate of Correctional Labour Camps), but the full official name of the agency changed several times.

Soviet dissidents were people who disagreed with certain features of Soviet ideology or with its entirety and who were willing to speak out against them. The term dissident was used in the Soviet Union (USSR) in the period from the mid-1960s until the Fall of Communism. It was used to refer to small groups of marginalized intellectuals whose challenges, from modest to radical to the Soviet regime, met protection and encouragement from correspondents, and typically criminal prosecution or other forms of silencing by the authorities. Following the etymology of the term, a dissident is considered to "sit apart" from the regime. As dissenters began self-identifying as dissidents, the term came to refer to an individual whose non-conformism was perceived to be for the good of a society. The most influential subset of the dissidents is known as the Soviet human rights movement.

From 12 January 1972 to 1973, a wide-reaching purge of Ukrainian society and intelligentsia was organised by Leonid Brezhnev and the KGB. Codenamed Operation Bloc (Russian: Операция «Блок», Operatsiya «Blok»; Ukrainian: Операція «Блок», Operatsiia «Blok»), the purge resulted in the arrest of 193 people, including most of the leaders of the Ukrainian dissident movement, as well as the removal of Petro Shelest and the installation of Volodymyr Shcherbytsky as First Secretary of the Communist Party of Ukraine.

From August 1965 to May 1966, the government of the Ukrainian Soviet Socialist Republic orchestrated a mass arrest of intellectuals associated with the counter-culture Sixtier movement. Occurring simultaneously with the Sinyavsky–Daniel trial, the purge occurred without the knowledge of western media until the publication of journalist Viacheslav Chornovil's petition (popularly known as The Chornovil Papers). An estimated 190–200 people were arrested during the purge.

Anti-Soviet Agitation and Propaganda (ASA) (Russian: Антисове́тская агита́ция и пропага́нда (АСА)) was a criminal offence in the Soviet Union. To begin with the term was interchangeably used with counter-revolutionary agitation. The latter term was in use immediately after the first Russian Revolution in February 1917. The offence was codified in criminal law in the 1920s, and revised in the 1950s in two articles of the RSFSR Criminal Code. The offence was widely used against Soviet dissidents.