"There is no place in Ontario for conversion therapy, which is based on the premise that being gay or transgendered is wrong and needs to be corrected," she said. "The use of conversion therapy to dissuade a person from self-identifying results in neither outcome and should not be tolerated."
Wynne, who is gay, spoke in favour of an NDP private member's bill that would make it illegal to attempt to change the sexual orientation or gender identity of someone aged 18 and under through therapy.
The premier said she had a lot of life experience when she came out in her mid-30s and understood her sexuality, unlike young people.
"I had the benefit of 36 years of life experience and I understood my journey in a way that an eight-year-old or a nine-year-old cannot possibly," she told the legislature. "They can be vulnerable to the notion that being gay is a choice, rather than being integral to who you are."
Private member's bills rarely become law in Ontario, but it's equally rare for a premier to speak in favour of one and to vote for it.
The bill by New Democrat Cheri DiNovo was approved unanimously on second reading Thursday and will go to the legislature's justice committee for consideration.
"I want to dedicate this to all of those victims who've been electro-shocked, shamed, suffered induced vomiting, induced paralysis, told they're not male or female enough," said DiNovo.
"There have been studies done that show children that have been through conversion therapy are eight times more likely to commit suicide than those who have not."
DiNovo said there are no professional bodies anywhere in the world that support conversion therapy "but it's still going on" in Ontario, which she discovered while touring the province with a committee on gay-straight alliances in schools.
"We had psychiatrists come before that committee that testified the majority of their practise was conversion therapy," she said. "Many of them were informed by fundamentalist religious convictions ... but many others across the faith spectrum say this has nothing to do with faith or religion."
There are no medical guidelines in Ontario that support therapy that would "convert" someone's sexual or gender identity, said Wynne, who promised the government will make sure the medical profession is aware of that fact.
"(Health) Minister Eric Hoskins will be sending a letter to the College of Physicians and Surgeons of Ontario and other relevant colleges explaining that their rules should not allow conversion therapy," she said.
DiNovo said she wants to make sure conversion therapy is no longer covered by Ontario's health insurance plan because some doctors have billed it under general counselling.
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