Australian of the Year Pat McGorry has backed calls for a Senate inquiry into Scientology, saying its views on mental health are putting lives at risk.

"They are the deniers of the realities of mental illness, which I find incredibly irresponsible and dangerous," he told ABC Radio this morning.

The renowned mental health expert has joined psychiatry boss Louise Newman and the Brain and Mind Institute's Ian Hickie in urging senators to vote for an inquiry.

The Senate is expected to vote on the issue, brought forward by independent senator Nick Xenophon, by the end of next week.

Professor McGorry met Senator Xenophon yesterday to lend his voice to the cause.