Sir

Your recent News Feature “Asia's tigers get the blues” (Nature 429, 696–698; 2004) notes that levels of depression and suicide are rapidly increasing in East Asia. The breakdown of traditional community structures, the loss of family-support systems, long-distance immigration and economic uncertainty all take their toll, in the form of a rise in mental disorders. As noted in the News Feature, this cocktail of psychological stresses leads to depression, substance abuse, eating disorders and other stress-related problems.

There is, however, another important reason for the rise of depression and other mental disorders in China. During the past year, almost half a billion people there have been affected by natural disasters such as floods and earthquakes, which have caused more than 2,000 deaths and the displacement of some seven million people, according to the World Health Organization (see http://www.who.int/disasters/country.cfm?countryID=10&DocType=2).

As the number of disasters — both natural and manmade — increases around the world, we can expect to see more stress-related disorders in the twenty-first century. Post-traumatic stress disorder (PTSD), in particular, can be caused by natural disasters or by the wars and acts of violence that afflict many parts of the world. Traumatic events do not discriminate on the grounds of culture, race, gender or age (see, for example, I. Derluyn et al. Lancet 363, 861–863; 2004). And people exposed to such events are far more likely to develop psychiatric disorders such as substance abuse, major depression, PTSD and psychosomatic illness (P. P. Schnurr et al. Science 303, 168–169; 2004).

The impact of PTSD is especially devastating in developing countries, where health services are helpless to cope with the flood of traumatized people seeking refuge and help.