Critics say that underlines the need to recruit uniformed psychiatrists, psychologists and counsellors.
A series of briefings and documents, obtained by the federal Liberals under access to information, show how officials scrambled to fill 54 vacant staff jobs amid a high-profile crisis where as many as 10 soldiers and veterans took their own lives within a three month period.
A briefing to Defence Minister Rob Nicholson shows that within weeks of being ordered to clear bureaucratic roadblocks, the department had extended job offers to 40 mental health workers.
Of those offers, 22 were accepted on the spot, nine were held up because of conditions such as security clearance and another nine were refused.
"With the number of conditional letters of offer made to date, the department has nearly depleted its current pool of potential candidates," said the March 20 document prepared by the assistant chief of military personnel.
"At this stage we anticipate a minimal number of offers to be issued because those qualified individuals remaining in the pool are not interested in the work locations are unwilling to relocate."
Last week, the auditor general took Veterans Affairs to task for delays in approving mental health treatment for ex-soldiers in a politically damaging report that kept the Harper government on the defensive.
National Defence is responsible for mental health programs while a person is still in uniform and the veterans department takes over when they retire.
National Defence tried to fill the vacancies by launching five ad campaigns, but officials said there were "no candidates in the pool or no interest in the location, such as Cold Lake, Alta. and Shilo, Man."
A spokeswoman for National Defence, Maureen Lamothe, said Friday there are still 32 vacancies out of a total number of 450 positions in the mental health branch. The staff benchmark was set in 2002.
The branch, which provides ongoing support to soldiers with post traumatic stress, depression and addictions has never been at full complement.
Liberal defence critic Joyce Murray says the problem is the department is putting its emphasis on hiring civilians, rather than recruiting uniformed mental health workers whose job would be to serve in outlying areas.
The military's top doctors made a case to former defence minister Peter MacKay in the spring of 2013 to hire uniformed psychologists, a plea that was ignored.
They would be useful whenever forces are deployed overseas, but "additionally it would provide us with the flexibility to address the shortage of psychologists in under-serviced areas," said an April 5, 2013 memo.
The Conservatives poured $11.4 million into military mental health in 2012 specifically to fill out the complement of staff and the briefing suggested using some of that money.
"I would not pin this failure on National Defence," said Murray.
"It is squarely on the Conservative government. What we're seeing is the mental health postings still unfilled. They are blocking the ministry from being able to do the right thing."
Uniformed members are more expensive for the federal treasury, in terms of long-term benefits, than civilians or contractors, Murray added.
But a spokeswoman for Defence Minister Rob Nicholson struck a conciliatory tone, suggesting the government might be willing to re-examine the idea.
"We are committed to ensuring that our brave men and women in uniform have the very best available health case possible," said Johanna Quinney in an email late Friday.
"The minister of National Defence will consider any proposal from the military to improve health services in the Canadian Armed Forces."
In the meantime, Lamothe said they are still trying to recruit.
"Our intensive recruiting efforts have proven successful in identifying skilled professionals wanting to join our clinics," she said.
"Additionally we have a large network of civilian mental health-care providers that we can refer patients to, should the need arise."
A senior official told a Commons committee last spring that incentives to get people to move had been improved and the department remained hopeful.
The documents show that a temporary blanket exemption was obtained from the public service commission to see the jobs filled on a priority basis and the federal treasury board waived the $5,000 limit on relocation expenses.
Some of those measures will expire on March 31, 2015.
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