Mass layoffs may trigger increased suicide attempts and other suicide-related behaviors among some teenagers, says new research from Duke University.

Lead author Anna Gassman-Pines found that when 1 percent of a state's working population lost jobs, suicide-related behaviors increased by 2 to 3 percentage points among girls and black adolescents in the following year. Among girls, thoughts of suicide and suicide plans rose. Among black teens, thoughts of suicide, suicide plans and suicide attempts all increased.

"Job loss can be an unanticipated shock to a community," said Gassman-Pines, who teaches public policy at Duke's Sanford School of Public Policy and is a faculty fellow of the Duke Center for Child and Family Policy. "We know that suicide increases among adults when communities are hit with widespread layoffs. Now we have evidence that teenagers are similarly affected."

The study, which appears online in the American Journal of Public Health, is based on a nationally representative survey of 403,457 adolescents from 1997 to 2009. Gassman-Pines also examined mass layoffs and closings in all 50 states and the District of Columbia, using data from the federal Bureau of Labor Statistics. The bureau defines a mass closing as a layoff affecting more than 50 workers.

In their analysis, Gassman-Pines and her Duke co-authors Elizabeth Ananat and Christina Gibson-Davis controlled for confounding variables, such as poverty rate and overall unemployment.

"Job loss was not simply a proxy for other aspects of the state's economic climate, but instead represented a meaningful economic shock, which led to changes in girls' and black adolescents' suicide-related behaviors," Gassman-Pines writes.

For girls, economic hardship appears to have worsened existing tendencies. On the whole, girls have higher rates of suicide ideation and planning than boys. Rates of suicide attempts are higher among black teenagers than among white teens.

Suicide is the third most common cause of death among American youths ages 10 to 24, causing 4,600 deaths annually. An even larger group of 157,000 youths ages 10 to 24 are treated for self-inflicted wounds each year. Gassman-Pines said she hopes the research may help mental health workers identify teens who could be suicide risks.