Homicide and Suicide in Megacities

Abstract

There are 28 megacities in the globe and most are located in Asia. The rates of suicide and homicide of these cities are compared with national rates and country economic indicators such as gross domestic product (GDP), human development index (HDI), and inequity index (GINI). Concerning homicide, the highest rate (per 100,000 habitants) in megacities is in Rio de Janeiro, Brazil (29.9), and the lowest in Tokyo, Japan (0.2). Homicide rates above 10/100,000, regarded as of epidemic violence, are found in Rio de Janeiro, Brazil; São Paulo, Brazil (14.2); Karachi, Pakistan (12.3); and Lagos, Niger (12.2). Concerning suicide, the mean rate per 100,000 habitants in 22 of these megacities is 7.2, the highest in Osaka (20) and the lowest rate in Cairo (0.7). Epidemic levels of suicides are found only in megacities in Asia. There is a relationship between economic indicators with suicide (high GDP and HDI and low inequity) and homicide rates (low GDP and HDI and high inequity). The rates of suicide and homicide tend to show inverse correlation. Nine cities have at least one rate above 10/100,000 and nine cities have both rates below 5/100,000. The overall homicide rates found in megalopolises are lower than the global mean of rates of homicides found for the countries as a whole, except in Rio de Janeiro, Brazil, and Karachi, Pakistan. The megacities present lower suicide rates compared with the overall rates of the countries where they are placed. As a conclusion, there is no common pattern for homicide and suicide rates in megacities, but when homicide is high, suicide tends to be low. Higher country development and better social indicators are related to increased risk of suicide.