A $10-million donation Wednesday by Bell Canada is described as "historic," and the largest corporate gift to mental illness in Canada.

It was announced as the Centre for Addiction and Mental Health in Toronto said it has exceeded a fundraising campaign goal and hit the $108-million mark.

"This kind of giving to mental illness is pretty much unheard of anywhere," Dr. Catherine Zahn, president and CEO of the centre, said in an interview.

"There just hasn't been this type of commitment from the private sector and civil society ... to support the public sector in our movement to create a better world, to help people with mental illness and addictions live their best lives."

Zahn said it coincides with people becoming more willing in recent years to talk about mental illness and declare an association with someone who experiences mental illness and addiction.

"It's like the world of cancer in the 1960s when there was developing an increasingly political and social voice to combat cancer, to bring cancer out of the shadows — and something similar is happening now in the world of mental illness and addiction," she said.

Last September, Bell announced a charitable program dedicated to the promotion and support of mental health across Canada.

"The Bell team is proud to be an integral partner in the CAMH community and for its central entry point — the Bell Gateway Building — to so visibly carry our name," George Cope, president and CEO of Bell and BCE Inc., said in a statement Wednesday.

"We support CAMH's world-leading vision to promote mental health by integrating the best resources and talent within a community framework."

The Bell Gateway Building will serve as a central hub for the centre's Queen Street campus in Toronto.

Zahn said funds raised by the centre's Transforming Lives campaign will go toward building redevelopment, research and programs focused on transmitting knowledge into practice at in-patient and out-patient programs.

The impact of mental illness on the workplace is significant, she said, and one of the top reasons for workplace disability payments.

Researchers are trying to better understand basic mechanisms of brain function that are altered or genetically created or have become wired through life experiences to create behaviours that society interprets as mental illness, she said.

"Once we understand these basic mechanisms, once we're able to visualize aspects of the brain that are functioning in ways that are different in people with mental illness and without mental illness, then we can identify strategies to mitigate the impact and to find treatments and potentially cures."

Zahn said there have been breakthroughs in recent years based on genetic research and brain imaging that clearly indicate differences in brains of people who are experiencing psychiatric symptoms.