Psychologist Susan Hook, who is also south-west chair of the Australian Psychological Society, said multiple royal commissions and changes to funding models meant demand had increased on a shrinking pool of local psychologists.

General practitioners refer patients to private practices with Mental Health Care Plans offering a 10-session rebate, which Ms Hook said was often insufficient to "work adequately on issues".

She said clients could also access lengthier support through the NDIS, but this had increased demand.

"There is a perfect storm going on at the moment," Ms Hook said. "A number of psychologists left at the same time as the NDIS started to ramp up."

She said she treated people with mild mental health difficulties and some with moderate to severe difficulties, and increased awareness of mental health had likely led to increased strain on private services.

"It seems to me we do not have enough resources, and we are raising people's expectations by talking about mental health and having it come in the open," Ms Hook said.

"We feel terribly guilty, our job is to help people. We are aware it really causes hardship for people because of these long waiting lists."

The pressures come as the Victorian government conducts a royal commission into mental health, and Australian Institute of Health and Welfare data shows a higher-than-average suicide rate among males in the south-west.

Ms Hook said there were opportunities for the private and public sector to work better together.

"There are significant structural limitations," she said.

South West Healthcare mental health services executive director Karyn Cook said the public service provided care to people with severe mental health issues and supported patients with milder conditions to navigate the system.

SWH chief Craig Fraser said public help was "available when people need" and wasn't strained.

He declined to provide South West Healthcare's submission to the royal commission but said it was "not at odds" with the state government's submission.

That submission highlighted geographic barriers to early engagement for people in rural and regional areas, and constraints on acute services, workforce and funding. It also identified gaps for people with moderate or ongoing mental illness and for children and young people.

Crisis support can be found at Lifeline (13 11 14), the Suicide Call Back Service (1300 659 467) and beyondblue (1300 22 4636).

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