Actor Owen Wilson's recent suicide attempt shocked many people. Wilson, star of a string of comedy hits including "Zoolander" and "Wedding Crashers" is rich, famous, and has been honored with an Academy Award nomination. He also has been depressed for months.

While Wilson's attempt was unexpected, it is not that uncommon. Overall, the public greatly underestimates the incidence of suicide.

About 30,000 people die by suicide each year in America. It is the ninth leading cause of death in this country, and higher for men than women.

And it's not just an American problem. Suicide is the second-leading cause of death for Canadian youth and young adults. Worldwide, there are an estimated 10 million to 20 million attempted suicides each year.

In fact, the suicide rate is higher than the homicide rate: Nearly a third more people die at their own hands than die at other people's hands (the murder rate in America is about 6 per 100,000; for suicides it's 10.8).

So for every two murders you hear about, three other people killed themselves.

One reason that people believe homicide is much more common than suicide is because of the news media's selective coverage.

Most people hear about the vast majority of deaths (such as accidents, homicides , and suicides) not from personal experience but from the news. Yet while murders make daily news, suicides and suicide attempts are often not considered newsworthy unless the victim is famous (such as Wilson, musician Kurt Cobain, or comedian Richard Jeni) or is part of a group (such as the Heaven's Gate cult).

There may be another reason why journalists are reluctant to cover suicide stories: They can lead to copycats, or what is called "suicide contagion," where others who are considering suicide are prompted to kill themselves from seeing news reports. While not common, it does happen, and helps to keep the true cost of suicides out of the public's mind.

Benjamin Radford is managing editor of Skeptical Inquirer science magazine. He is co-author of "Hoaxes, Myths, and Manias: Why We Need Critical Thinking" (2003). This and other books are noted on his website.