Wait times for GPs at Townsville's Lavarack Barracks are short but service personnel on average endure six to eight weeks waiting for appointments with a psychiatrist.
Lavarack Barracks' certified psychiatrist works just two days per week and services the near 5000 personnel on base.
Warrant Officer Class 1 Brian Buskell told the commission on Monday the delays have negative impacts on soldiers needing help with their mental health.
"I try my hardest to help them in any way I can... but it has a negative impact and they feel it is not fair," he said.
But WO1 Buskell argued the the morale of the unit as a whole had not been undermined.
"I don't think so. When you look at morale and the happiness of a unit; I look at, can the unit excel in arduous situations and can it complete it's task?
"They do - but I don't think it has a detrimental effect on morale at the base at the moment, no."
On Tuesday, the former chair of the Defence Abuse Response Taskforce, Len Roberts-Smith, will provide evidence to the commission over two days.
The taskforce was established in 2012 to assist complainants who had suffered sexual and physical abuse as well as sexual and work place harassment in defence prior to April 2011.
Mr Roberts-Smith will give evidence on the purpose and function of DART, its achievements and how it engages with the department of defence.