A new report from researchers with the Johns Hopkins Center for Injury Research and Policy finds the majority of the previously reported increase in suicide in the U.S. between 2000 and 2010 is attributable to an increase in hanging/suffocation, which increased from 19 percent of all suicides in 2000 to 26 percent of all suicides in 2010. The largest increase in hanging/suffocation occurred among those aged 45-59 years (104 percent increase).

The results are published in the December issue of the American Journal of Preventive Medicine.

"Suicide recently exceeded motor vehicle crashes as the leading cause of injury death in the U.S; this report is the first to examine changes in the method of suicide, particularly by demographics such as age," said lead study author Susan P. Baker, MPH, a professor with and founding director of the Johns Hopkins Center for Injury Research and Policy, part of the Johns Hopkins Bloomberg School of Public Health. "While suicide by firearm remains the predominant method in the U.S., the increase in hanging and suffocation particularly in middle-aged adults warrants immediate attention."

The researchers also found that the proportion of suicide by poisoning increased, from 16 percent in 2000 to 17 percent in 2010. Much like hanging/suffocation, dramatic increases were seen in certain age groups: the increase was 85 percent in those aged 60-69 years. Taken together, suicide by firearm, hanging/suffocation and poisoning make up 93 percent of all suicides in the U.S.

"In addition to age, detailed examination revealed important differences across gender and race," explained co-author Guoqing Hu, of Central South University, School of Public Health, China. "Suicide rates are increasing faster for women than for men, and faster in whites than in non-whites." The suicide rate increased the most among those aged 45-59 years of age (by 39 percent); in contrast, it dropped by 8 percent among those 70 and older.

Baker and colleagues used data from the CDC's Web-Based Injury Statistics Query and Reporting System (WISQARS) to determine the characteristics of the changes in suicide rates between 2000 and 2010. The increase in suicide overall in the U.S. was first reported earlier in 2012, and is thought to be related in part to the effects of the economic recession.

"Recognition of the changes in suicide methods is a critical precursor to developing prevention programs and services," concluded Baker. "Strategies that have demonstrated efficacy in inpatient settings such as installing break-away closet bars, lowering the height of anchor points and increasing awareness of risk indicators should be given greater attention for their potential to reduce suicide in other settings."

Support for this research was provided by the National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, through a grant to the Johns Hopkins Center for Injury Research and Policy. Additional support came from the 2009 New Central Scholar Support Grant of Ministry of Education of China and the National Institute of Mental Health.