It's believed more patients than first thought were admitted to the Lake Alice Psychiatric Hospital's Child and Adolescent Unit in the 1970s.
It was thought 200 young people passed through the unit, but now the number is closer to 300. The Abuse in Care Royal Commission wants to hear from as many of them as possible.
Patients say they were subjected to massive doses of medication and the use of electroconvulsive therapy as a punishment in the unit between 1972 and when it closed in 1978.
Lead Investigation counsel, Andrew Molloy says no official records were kept, but the new figure has come about from information received from former patients.
