The 48-year Arap, who is active in the opposition United Civic Front, was forcibly hospitalized in what she says was retribution for an article she had written denouncing abuse against patients at another local psychiatric clinic.
Arap alleged in her article that children and adolescents held in the Murmansk regional psychiatric hospital in the remote city of Apatity were regularly subjected to electroshock treatment and sexual abuse.
Arap's release comes after a commission sent by human-rights ombudsman Vladimir Lukin found no reason for her forced internment. The president of Russia's Independent Psychiatric Association, Yuri Savenko, examined Arap and said she was being hospitalized without any medical basis.
Human rights groups have called Arap's internment a throwback to Soviet-era practices of using "punitive medicine" to suppress dissent.
(AP, Interfax, ITAR-TASS)