Vancouver Canucks fan pays tribute to former hockey player Rick Rypien during a gathering in Vancouver
A Vancouver Canucks fan pays tribute to hockey player Rick Rypien during a remembrance ceremony at Rogers Arena in Vancouver, British Columbia August 17, 2011. Rypien, who played for six years for the NHL team, was found dead in his home in Alberta on Monday. Reuters

The recent deaths of three North American athletes have nudged the spotlight away from doping and concussions to shine a light on another of elite sport's darkest secrets -- depression.

It has been a tragic off-season for National Hockey League players and fans who have been rocked by the deaths of Canadians Rick Rypien, 27, and 28-year-old Derek Boogaard.

The Olympic community has also been shaken by the suicide of 29-year-old U.S. freestyle skier Jeret 'Speedy' Peterson, a silver medalist in the aerials at the 2010 Vancouver Olympics.

While drug-testing and concussion prevention are now discussed openly in locker rooms in sports leagues around the world, depression, a disease that affects millions, remains prevalent in professional sport but paid little attention until tragedy strikes.

Rypien, a scrappy forward who had just signed a one-year contract to play for the Winnipeg Jets, was found dead in his apartment on Monday.

The coroner has yet to determine the cause of death but Rypien had grappled with depression for a decade, a disease that had threatened to derail his NHL career several times.

New York Ranger Boogaard, one of the NHL's most feared enforcers, was found dead in his apartment in May. His death was deemed an accident caused by a lethal cocktail of alcohol and painkillers.

Peterson, who had admitted to problems with alcohol and depression, was found dead from a self-inflicted gunshot in a remote canyon in Utah.

I think there remains a significant stigma (about depression) in the general population but more so in the professional athlete, Dr. Don Malone, head of the Psychiatric Neuromodulation Center at the prominent Cleveland Clinic, told Reuters.

There's an aspect to it in the athletes that they want to keep it hidden.

Athletes are not immune. They can suffer silently.

Rypien and Boogaard earned their living on the NHL's unforgiving fringes, and were fighting to keep their places on their teams.

SUBSTANCE ABUSE

Rypien, the son of former amateur boxing champion, reputedly loved his job and delighted in squaring off with bigger, heavier challengers as an NHL tough guy.

He had sought help from the league's substance abuse and behavior health program which was put in place in 1996 to help players and their families deal with a variety of issues from grief counseling to drug abuse and depression.

About 14.8 million Americans are diagnosed with depression each year. About seven million receive treatment, according to Dr. Alan Manevitz, a clinical psychiatrist at Lenox Hill Hospital in New York.

Hall of Fame quarterback Terry Bradshaw, nine-time tennis grand slam champion Monica Seles and Cy Young award-winning pitcher Zack Greinke all waged battles with depression.

Former Toronto Maple Leaf great Ron Ellis is now a speaker on the importance of diagnosing and treating clinical depression.

When you're on top of your career, there is intense pressure to stay on top ... particularly in incredibly competitive careers like in pro sports, show business, Jeffrey Parsons, an addiction expert and professor of psychology at Hunter College in New York, told Reuters.

The reasons that might tend to weigh on someone could lead to depression suicide and substance abuse with the spotlight being on them so heavily and so often.