Many researchers within the World Health Organization suspect that estimates of mental disorders in middle-income countries are too low. A new WHO study of China supports this by finding that 17.5% of the population has some type of mental disorder.

The WHO study cast a wide net, sampling 96 urban and 267 rural sites spanning four provinces. Participants were randomly selected to be screened with a Chinese version of the Structured Clinical Interview for DSM-IV and a longer version of the General Health Questionnaire.

In addition to the raw prevalence of disorders, researchers discovered a number of fascinating statistics. Alcohol disorders were 48 times more common in men than women, and rural subjects were more likely than urban subjects to suffer alcohol dependence and depression. These gender and geographical differences could alert health organizations about pernicious social forces that disproportionately increase these rates.

Another sad finding was that only 8% of those with a mental illness had ever tried to get professional help, and only slightly more than half of those who tried ever got to see a mental health professional. These low numbers could be improved with publicity campaigns and greater access to mental healthcare.