WINNIPEG -- The chairman of Canada's Truth and Reconciliation Commission says all professions should have to undergo mandatory training about residential schools as the country tries to undo some of the deep-seeded trauma inflicted by the policy to "take the Indian out of the child."

Justice Murray Sinclair told a suicide prevention conference in Winnipeg on Wednesday that judges are legally required to learn about residential schools and the same should be mandatory for anyone working with aboriginal people.

"There isn't a single profession in Canada that shouldn't be required to understand the aboriginal experience in this country because all professions deal with aboriginal people, particularly in the West, where the population of aboriginal people is so significant," Sinclair said.

Medical professionals in particular need to understand the legacy of residential schools, he said.

"This requirement should be imposed upon all of those who are treating aboriginal people," Sinclair said. "Every medical doctor and every nurse being trained at a training program at a hospital or university in this country should be required to take a course in the residential school experience."

Sinclair pointed to a Winnipeg hospital where an aboriginal man in a wheelchair died during a 34-hour wait in the emergency waiting room. The Health Sciences Centre in Winnipeg serves not only urban aboriginals, but all those from northern Manitoba who are sent for medical treatment, Sinclair said.

"All of those aboriginal patients are being sent to professionals who have not been trained in cultural competence," he said. "That's contributed to hesitation on the part of the aboriginal community to seek medical advice when they feel they are not going to be treated properly. That exacerbates the problems that they face."

About 150,000 First Nations, Inuit and Metis children were taken from their families and forced to attend the government schools over much of the last century. The last school, outside Regina, closed in 1996.

The $60-million truth and reconciliation commission is part of a landmark compensation deal between the federal government, the Crown and residential school survivors. Sinclair and his commissioners have visited hundreds of communities and have heard graphic details of trauma, including rampant sexual and physical abuse.

Of the 80,000 people who have made claims under the compensation deal, Sinclair said half say they sustained injuries of one form or another. Survivors suffer from depression, thoughts of suicide, substance abuse and an inability to show affection, he said. Those who live with survivors suffer as well, Sinclair said.

"Trauma feeds on trauma. Once there is a cycle that's started of suicides or crime or physical violence, it begins to feed upon itself and passes from generation to generation," Sinclair said. "Residential schools are probably the most significant historical trauma that aboriginal people in this country have experienced."

The commission has nine months left in its mandate but Sinclair said it may require an extension. The commission has had difficulty obtaining documents in Library and Archives Canada, despite a court order requiring all archival records be turned over, he said.

Bureaucratic and "systemic" delays may mean the commission will have a hard time meeting its deadline of July 1, 2014, Sinclair said.

"We've raised that with the parties and we'll have a discussion with them soon once we know when the documents can start to flow," he said.