Changes in suicide mechanisms: Twenty year trends

Background/Purpose Suicide has been among the leading non-natural causes of death in San Diego County over the past twenty years. The purpose of this study was to examine trends in suicide mechanisms during this time period. Methods Using the San Diego County Medical Examiner's database, we analyzed all suicides occurring in San Diego County from 1991 through 2010. Results/Outcomes From 1991 through 2010, 6,870 individuals died from suicide in San Diego County, an average of 344 per year. The rate has declined by 17.6% over this time, from 14 per 100,000 in 1991 to 11.5 per 100,000 in 2010. The rate of suicide from firearms fell the most; the five-year rate fell 39% from 1991-1994 (6.9 per 100,000) to 2006-2010 (4.2 per 100,000). Hanging/asphyxia had the greatest percentage increase at 25%, from 2.2 to 2.8 per 100,000, while suicides from overdose/poisoning stayed fairly steady (2.52 to 2.48 per 100,000). Mechanism-specific trends varied by age group. Adults 65 years and older experienced decreases for every major mechanism, while suicide rates due to hanging/asphyxia increased in younger age groups. Conclusions The large decline in firearm-related suicides over the past twenty years has driven the overall decline in suicides, as other methods have remained relatively stable. The increased rate due to hanging/asphyxia suggests that there may have been some substitution of method, but not enough to balance out the firearm-related decline. Federal laws implementing waiting periods to purchase handguns in the mid-1990s may have played a role in these trends.