The study, published in the American Journal of Preventive Medicine, found substantial increases in suicide by hanging/suffocation and poisoning in the United States.
Susan P. Baker, Holly C. Wilcox and Dr. Timothy D. Baker, all of The Johns Hopkins University, and Guoqing Hu of the School of Public Health at Central South University, in Changsha, China, said they used data came from the U.S. Centers for Disease Control and Prevention's Web-Based Injury Statistics Query and Reporting System.
The overall U.S. suicide rate increased 16 percent, or 10.4 to 12.1 per 100,000 population from 2000 and 2010. Fifty-two percent of the increase was attributable to suicide by hanging/suffocation and 10 percent by poisoning.
The analysis also showed suicide by hanging/suffocation increased by 104 percent among those ages 45-59 years and rose steadily in all age groups except those age 70 and older; the largest increase in suicide by poisoning -- 85 percent -- occurred among those ages 60-69.
Suicide by firearm decreased by 24 percent among those ages 15-24 but increased by 22 percent among those ages 45-59, the study said.