Feb. 4 (HealthDay News) -- Risk factors for suicidal thoughts, plans and attempts are similar in many countries, new research suggests.

The study, which used data collected by the World Health Organization World Mental Health Survey Initiative, looked at people in 17 nations and found that an overall average of 9.2 percent reported having seriously thought about suicide and 2.7 percent attempted suicide. It also found that suicide risk factors are associated with having a mental disorder, being female, younger, less educated, and unmarried.

"Our research suggests that suicidal thoughts and behaviors are more common than one might think, and also that key risk factors for these behaviors are quite consistent across many different countries around the world," study leader Matthew Nock, associate professor of psychology at Harvard University, said in a prepared statement.

The findings were published in the February issue of the British Journal of Psychiatry.

While the overall averages were 9.2 percent for suicidal thoughts and 2.7 percent for attempted suicide, there were variations from country to country. For example, rates of suicidal thoughts ranged from 3.1 percent in China to 15.9 percent in New Zealand. But the researchers noted that people in some countries wouldn't report having suicidal thoughts because it's culturally unacceptable, meaning those countries would have much lower rates.

In high-income countries, the strongest risk factor associated with suicidal thoughts and behaviors was mood disorders; in low- and middle-income countries, it was impulse control disorders.

"We often think of suicidal thoughts and behaviors as occurring among people who are depressed, but across all of these countries, we found that it is not just depression that increases the risk of suicidal behaviors -- impulse control disorders, substance abuse disorders and anxiety disorders are all associated with a significantly higher risk of suicidal thoughts and attempts," Nock said.

Among people with suicidal thoughts, the risk of making a suicide attempt was strongest among those with substance abuse and impulse control disorders, which suggests these disorders are most strongly associated with acting on suicidal thoughts.

The study also found that among people with suicidal thoughts, 29 percent later made a suicide attempt, and these attempts were most common within the first year after the onset of suicidal thoughts.

Among people with both suicidal thoughts and a plan, there was a 56 percent probability of a suicide attempt, compared with 15.4 percent among those without a plan.

The study looked at 84,850 adults in Nigeria, South Africa, Colombia, Mexico, the United States, Japan, New Zealand, China, Belgium, France, Germany, Italy, the Netherlands, Spain, Ukraine, Israel and Lebanon.

Suicide is a leading cause of death worldwide. This is the first study to examine the suicidal thoughts and behaviors of people in numerous and diverse countries.

SOURCE: Harvard University, news release, Jan. 31, 2008