Three children earned class-action status Thursday in a lawsuit claiming Missouri overprescribed psychotropic medications to thousands of kids in foster care, to sedate them rather than for a valid medical purpose.

In what has been called a landmark case, advocacy groups Children’s Rights, National Center for Youth Law, and St. Louis University School of Law Legal Clinics sued Missouri on behalf of three foster children in June 2017, alleging the state was unlawfully prescribing drugs without regard to the harms they can cause, in violation of the children’s civil rights.