TORONTO -- The adoptive mother of a troubled inmate refused to discuss her daughter's parentage despite its obvious importance to the teen's mental health, an inquest into Ashley Smith's prison death heard Monday.

In her testimony, psychologist Cindy Presse told jurors that staff at the Regional Psychiatric Centre in Saskatoon believed it vital for Smith to have the family issue in the open.

But at a meeting in late February 2007, a visiting Coralee Smith made it clear she would not talk about her adoptive daughter's background.

"I got a blank look," Presse, chief psychologist at RPC, told the inquest.

"The message is, 'No, I'm not telling you."'

As she did with other prison staff, Smith had talked to Presse about her suspicions of her parentage.

Smith believed her sister -- 19 years older than her -- was really her biological mother, and Coralee Smith was in fact her grandmother.

She also believed her sister's son -- two years older than Smith and with his own troubles with the law -- was really her brother, jurors heard.

Her view was reinforced when Smith first entered the jail system as a 15-year-old in New Brunswick.

"A guard said, 'Oh, my God: You must be (his) sister,"' Presse said Smith told her. "'You look exactly like him."'

Presse said it was obvious the family "secret" distressed the teen but Coralee Smith "wouldn't go there."

When Coralee Smith testified earlier this year, presiding coroner Dr. John Carlisle ruled any questions to her around the parentage issue were off-limits.

Presse also testified that Smith became highly addicted to choking herself.

"She was quick to say, 'It's not sexual, Cindy,"' Presse testified. "She said it just made her feel good."

Smith, then 18, arrived at the psychiatric prison Dec. 20, 2006, from another facility in Nova Scotia.

Presse, the chief psychologist at RPC, said she arranged for the inmate to call home and gave her some magazines.

Within hours, however, Smith began showing the same acting-out behaviour that had driven staff at other prisons to distraction.

She covered her segregation cell camera and window with magazine pages. She dismantled the sprinkler head. She forced staff constantly to go into her cell to cut off ligatures she had secreted in a body cavity from her neck.

"A little TLC didn't go very far in controlling her behaviour," Presse told the inquest.

The psychologist drew a clear distinction between "parasuicidal" or self-harming behaviour and suicidal behaviour.

The former, which includes cutting or choking oneself, she said, is a form of addictive self-stimulation that's not intended to be lethal.

However, Presse said, it is important to ensure parasuicidals don't actually kill themselves in their quest for a more intense sensation in the way a drug addict might take increasingly powerful doses.

"You've got to keep the patient safe, but you don't really want the big commotion."

Smith, the jurors heard, didn't like her small bare isolation cell at RPC, where the little external stimulation she had -- such as a radio -- would be removed when she misbehaved.

Presse conceded the punishment made little sense since the acting out was often a way to relieve boredom. She also said people like Smith don't belong in prison.

"Corrections isn't the place for these kinds of treatment programs," Presse said. "There's a reason why there are treatment centres."

The "fresh-faced" Smith stood out from other RPC inmates, who were likely to be low-functioning street people or drug addicts, jurors heard.

Notes from the time indicate the difficulty staff had dealing with Smith's volatile behaviour.

"Ashley impresses as extremely immature; she seems to see her non-compliance as a game," Presse wrote at one point.

But at another point she wrote that Smith "certainly can present as bright and reasonable when she chooses."

However, Smith was resistant to improving her behaviour or thinking about the future, Presse testified.

"I don't want to make changes in myself. I like the way I am. I don't know why I behave the way I do, but there's nothing bothering me," she told the psychologist at one point.

Smith, of Moncton, N.B., choked herself to death at a prison in Kitchener, Ont., in October 2007 as guards, ordered not to intervene, looked on. She was 19.