Celebrity and mental illness isn't the first thing that leaps to mind when people follow the rich and famous. Yet fame doesn't make any person immune to mental health issues.

From Abraham Lincoln and Winston Churchill to Catherine Zeta-Jones and Demi Lovato, mental illness has touched many people living in the public eye.

In fact, according to Health Canada about 20 per cent of the general population will suffer from a mental illness at some time. The other 80 per cent will be affected by mental illness after it touches family members, friends or colleagues.

Those statistics are just as true for celebrities as they are for the average person.

"Mental illness is a medical illness. It does not discriminate," said Dr. Nizar Ladha, an associate professor of psychiatry at Memorial University in St. John's, N.L. and the immediate past president of the Canadian Psychiatric Association.

"Some famous people are more private about their mental health issues. Others come forward. Those that do can have a profound impact on raising public awareness and debunking the misconceptions people have about mental illness," Ladha said.

Despite many strides forward over the last 50 years, mental illness still carries a stigma and the perception that those who live with it cannot lead normal lives.

"When a celebrity walks into a consulting room for treatment and is prepared to come forward you cannot help but become enthusiastic," said Ladha.

"When they come forward and say ‘I have mental illness, but it's treatable,' it's a help to all patients and to the concept of mental health," said Ladha.

To that end, these Canadian celebrities have taken up the cause to validate mental illness and the recovery from this disease.

Margaret Trudeau

In her youth, Margaret Trudeau always felt a kinship with people who had mental health issues. Today, Trudeau believes that affinity foretold what she would go through later in her life.

In 2006, the wife of former prime minister Pierre Trudeau told the world that she was fighting her own personal battle against bipolar disorder.

"It was a terrible struggle for me, like walking through the dark all alone," Trudeau, 63, told CTVNews.ca recently.

After the birth of her son, Alexandre "Sacha" Trudeau, on Christmas Day in 1973, Trudeau was struck with an overwhelming depression. She was diagnosed with postpartum depression and received treatment. But at the time, Trudeau's doctors did not realize that she was suffering from bipolar disorder.

This disorder, also known as manic depression, is a mental illness that manifests itself through extreme mood swings.

Trudeau's family, including husband Pierre, tried to help her. But no one knew what was wrong.

"I coped in silence," said Trudeau. "Now, when I look back, I wish I had done things very differently."

"Unfortunately, when I did get the serious treatment that I needed and the tools that could help me live with bipolar disorder I had to have a family intervention and be taken into the hospital," said Trudeau.

"I was so sick. I could not see the light at all. I could not be reasoned with," she said.

Trudeau's illness intensified in November of 1998, when her son, Michel Trudeau, was killed by an avalanche that swept him to the bottom of British Columbia's Kokanee Lake.

The death of her first husband, Pierre, in 2000, also brought on another bout of depression.

"I was mad with grief," said Trudeau.

"I didn't want to breathe or participate in life."

Yet these deaths forced Trudeau to take charge of her illness.

Overcoming the stigma that had held her back for years, she admitted herself into the Royal Ottawa Hospital in 2001 and was officially diagnosed with bipolar depression.

As an in-patient, Trudeau began receiving medication and therapy as doctors tried to stabilize the fluctuations between extreme euphoria and severe depression.

Today, Trudeau believes that hormonal fluctuations played a huge role in her illness.

"There's a tremendous new wave of thinking about how much hormones affect women's mental health and the propensity to go into bipolar crisis at times of fluctuations," said Trudeau.

Now, as an advocate for mental health, Trudeau travels the country to educate people about the disease. She also documented her experiences with bipolar disorder in the 2010 book, "Changing My Mind."

"I want people to remember that the brain is an organ, just like any other organ in the body," said Trudeau.

"It sounds so basic, but today I eat well, sleep well and make good choices in my life to support my health," she said.

Hope also had a healing power, according to Trudeau.

"In my life, I've felt guilt and shame about my mental illness. But with hope, and the love and support of your family, you can make it through this disease. You can find the reason to live," she said.

Elizabeth Manley

Back in the 1980s, Canadian figure skater Elizabeth Manley was Canada's sweetheart. She was also "the typical elite athlete." She did what she was told by her coaches. She trained. She also didn't speak up very much.

"We were very robotic in those days," said the 46-year-old Manley, who went on to become a 1988 Olympic silver medalist, 1988 World silver medalist and three-time Canadian champion.

But the pressures of training, coupled with her inability to voice her true feelings, crippled the teenaged Manley by the 1982-1983 skating season.

Around that time, Manley's coach left her unexpectedly. The coach-less 17-year-old was then sent to train in the United States, away from her mother, family and friends.

With the Sarajevo Olympics just a year and a half away, Manley felt utterly alone. That feeling was magnified by the divorce of her parents.

It wasn't long before Manley's body began to crack under such pressure.

Despite her stringent diet and gruelling training schedule, Manley suddenly gained 20 lbs. The teenager's hair also began to fall out in clumps.

"My body just fell apart," Manley told CTVNews.ca recently.

"It was telling me and everyone around me that something was very, very wrong. That's when I knew I needed to reach out for help and find out what was wrong with me," she said.

Manley was diagnosed with having a nervous breakdown and depression. Ironically, the diagnosis proved to be much tougher for those around her than Manley herself.

"For me this was an illness, just like any other illness. I needed help. I got treatment. I was going to be okay. But people around me suddenly began to disappear from my life. They didn't know how to deal with this disease, or me. There was a huge stigma attached to this disease at the time," said Manley.

Even Manley's father was reluctant to see his daughter share her story and write about her illness in her 1990 autobiography, "Thumbs Up!"

"I remember my father looking at me and saying ‘Why would you want to do this?' I told him if this book helps just one other kid or adult, I'll have done a good thing," said Manley.

Today, Manley looks back on her battle with depression with gratitude.

"Going through depression was the best thing that ever happened to me," said Manley.

"It did a lot for me, both as an athlete and a person. It taught me to be more compassionate and giving, to speak up and to take care of me," she said.

Dealing with depression also equipped Manley for tough events that followed years later, such as the death of her parents.

"When I look back on my life it all comes down to what happened to me in 1983," said Manley, who now champions mental illness and speaks across the country about the disease.

"Today, I have this amazing life -- and I'm a victim of mental health. I'm still capable of doing many things, contrary to what some people might still believe," she said.

"That's why I think of myself as the poster child for mental illness. People look at me and think ‘She can't be sick.' But I have a disease and it's treatable. That's what I want people to know. Mental illness doesn't mean the end."

Amy Sky

Throughout her career, Canadian singer and songwriter Amy Sky has written hits for Anne Murray, Reba McEntire, Diana Ross, Olivia Newton-John and other pop stars.

She's been nominated for Juno Awards and juggled success with motherhood, raising her son, Ezra, and daughter, Zoe, with musician-husband musician Marc Jordan.

But even with all these achievements, Sky suffered through three bouts of depression before she sought treatment and went public with her illness in 2007.

"I never admitted that I had a problem until my third episode of depression. It wasn't related to postpartum, but I could not cope on my own," Sky, 51, told CTVNews.ca recently.

With the help of a therapist, Sky embarked on a treatment plan that involved medication and cognitive behavioural therapy. Her fans, however, knew nothing of Sky's troubles.

"Sharing my story has made me feel vulnerable at times. But the gratitude I have received from those who needed to know that successful people are just as prone to illness as anyone has been very rewarding," said Sky.

Her journey through depression has also taught the star some invaluable life lessons.

"I have discovered that I am much more resilient than I thought and that secrets only have power when they are secret," said Sky.

"There is no such thing as being perfect," she said.

"Going through an episode of depression will not tarnish you for life. It's just like any illness. It's treatable, preventable and it's something we can recover from with the right help."