The New South Wales Mental Health Minister, Paul Lynch, says fringe groups will not be allowed to dictate the states' health policy.
Scientologists have written numerous letters to MPs, criticising the use of psychiatric drugs for the mentally ill.
Scientology rejects the use of psychiatry and anti-psychotic medications to treat mental illness.
Earlier this week, a court heard that a woman charged with stabbing her father and sister to death in south-west Sydney was denied psychiatric help because of her parents' belief in Scientology.
Mr Lynch says the government's position on the issue is clear.
"We have some of the best mental health experts in the world working in our mental health system," he said.
"We've got record amounts of funding going into the mental health system in New South Wales."
"There is no way that fringe groups are going to determine the way that our policy is set, and how our services are delivered."