BOSTON — A Brookline woman filed a lawsuit against the state prisons department Monday, saying her 31-year-old son has been restrained for long periods at a state psychiatric hospital in violation of state law.

Joanne Minich said in her complaint filed in Norfolk Superior Court that her son, Peter Minich, has been held in prolonged isolation at Bridgewater State Hospital and continuously deprived of almost all human contact and exercise for more than 6,300 hours since January 2013.

Peter Minich, who was diagnosed with paranoid schizophrenia, has also been placed in mechanical restraints for more than 800 hours over 12 months, for as long as 50 consecutive hours, according to the lawsuit.

The suit seeks an injunction to prevent further restraint and Peter Minich’s transfer to another hospital.

The lawsuit names as defendants the state Department of Correction, the top administrator at Bridgewater State and the contractor that provides mental health services at the hospital.

Bridgewater State deferred comment to the state Department of Correction, which did not immediately return telephone messages left seeking comment. A telephone message was also left for the contractor.

Peter Minich was civilly committed to the state Department of Correction facility after he was accused of assaulting staff at another state mental health facility. He has not been convicted of a crime.

“My son has an illness, in the same sense as someone with cancer or dementia. The last place he belongs is in a seclusion room behind a solid steel door,” Joanne Minich said in a statement.

State law prohibits the use of seclusion and restraint except for emergencies including “extreme violence” or “attempted suicide,” according to Joanne Minich’s lawyer, Eric MacLeish.

Minich was secluded and restrained for reasons such as “yelling,” ”bothering another patient,” ”standing on his sink,” and having “auditory hallucinations,” he said.