Forensic psychiatric examinees are admitted to the Hospital at the order of a court. The Finnish Institute for Health and Welfare (THL) determines the institution where each psychiatric examination will be carried out. The Mental Health Act states that the examination may last a maximum of 2 months. On the basis of the Mental Health Act a person undergoing psychiatric examination may be kept at the hospital against his or her will.
In 2022 Niuvanniemi carried out a total of 43 psychiatric examinations, with approximately ten examinees at the hospital at any one time.