A D.C. Superior Court judge has granted a teen-aged girl's request to be released from a private psychiatric institute in the District over the objections of the girl's mother, who had signed her in two weeks ago.

Judge George H. Goodrich granted the request at an emergency hearing after an attorney for the 16-year-old Lanham girl had asked the court that she be released. The girl's mother had signed her into the Psychiatric Institute of Washington on April 21.

Although an attorney representing the girl's mother told Goodrich that releasing the girl from the hospital would interfere with the mother's right to determine what was in her daughter's best interest, Goodrich ordered the girl released after hospital attorneys acknowledged that she no longer needed impatient care.

Goodrich's ruling last Friday set no broad precedent, but the girl's challenge to the private mental health facility was seen as a rare test of the legal rights of a juvenile contesting what generally is considered a voluntary commitment made by her parents.

"A voluntary patient under the age of 18 has rights too," said James Nickelsporn, the girl's attorney, "and cannot be subjected to the whim of her mother and father just because they wanted to place her in a psychiatric hospital."

In court papers filed on behalf of the girl, a Prince George's County high school student who works as a part-time cook at a fast-food restaurant, Nickelsporn said the girl "is not a mentally ill person. She does not suffer from any psychosis or other disease which substantially impairs [her] mental health. . ."

The mother's attorney, Carl Womack, told Goodrich at the court hearing that hospitalization was "in her child's interest" and that the child "will be the last to admit it.

"If you take her out of there (the hospital) you interfere with her (the mother's) rights as custodial parent," Womack argued.

Thomas A. Guidoboni, the hospital's attorney, told Goodrich the girl could be released and was not a danger to herself or the community. After the hearing, the girl's mother said she was disappointed that the hospital did not take a stronger position on her behalf, and that she believed the hospital was trying to avoid a legal battle.

The hospital's attorney's said the Psychiatric Institute of Washington located at 4460 MacArthur Blvd. NW, has approximately 100 beds and costs about $300 a day. It is one of more than a dozen institutions which form the Psychiatric Institutes of America, the nation's biggest chain of private psychiatric hospitals.

Under District law, a parent can voluntarily place in a mental institution a child under 18 and, likewise, can withdraw the child as a patient.

Daniel Yohalem, legal director of the Children's Defense Fund, said the reason it is rare for children to contest their parents' decision to commit them to private mental institutions is that it is difficult for such children to obtain lawyers.

In public mental hospitals such as St. Elizabeth Hospital in D.C., court procedures protest patients' rights, Yohalem said.

Hospital attorney Guidoboni said the Psychiatric Institute had "provided her (the girl) the due process which she would have been afforded had she been brought to a public hospital," and that an initial psychological screening had taken place.

In an interview after the court hearing, the girl said she was pleased with the judge's decision and that she believed she was not mentally ill. Goodrich released the girl into her mother's custody, and attorneys close to the case said that further psychiatric evaluations would be arranged on an outpatient basis.