The potential relationship between two important public health problems in China - schizophrenia and suicide - has been highlighted by an epidemiological study conducted by the Beijing Suicide Research and Prevention Center.

Researchers found schizophrenia was more prevalent in women than in men and more common in urban than in rural areas.

Risk of suicide was substantially greater in people with schizophrenia; about 10 percent of all suicides are attributable to schizophrenia.

Of rural residents, the relative risk of suicide of men with schizophrenia was higher than that of women.

However, this relative risk was higher in urban women with schizophrenia than in urban men.

Schizophrenia is a chronic, severe and disabling brain disease. Approximately 1 percent of the population develops schizophrenia during their lifetime.

People with schizophrenia often suffer terrifying symptoms such as hearing internal voices not heard by others, or believing other people are reading their minds, controlling their thoughts or plotting to harm them.

These symptoms may leave them fearful and withdrawn.

Their speech and behavior can be so disorganized, they may be incomprehensible or frightening to others.

Unlike almost every other country in the world, the prevalence of both schizophrenia and suicide in China is higher in women than in men.

Considering that schizophrenia and suicide are important public-health problems for China that may be related to one another, Dr. Michael Phillips and his colleagues carried out their studies by making use of existing data and studies.

Higher risk of suicide

These included data from the national psychiatric epidemiological study, the Ministry of Health's mortality registry, the census, and the national psychological autopsy study to estimate frequencies and rates of schizophrenia, suicide, and suicide in people with schizophrenia aged 15 years and older in China from 1995 to 1999.

The proportion of all suicides attributable to schizophrenia was 9.7 percent.

Risk factors for suicide vary in people with different mental disorders, so identification of illness-specific risk profiles would improve prediction of suicides and help tailor prevention efforts.

Not like depression, believed to be most strongly associated with suicide, the data of the schizophrenic group in several surveys in the past years in China has remained similar.

As a result, the researchers believe the relation between schizophrenia and suicide can be more accurately obtained, noted Phillips.

Researchers found the difference in suicide rates by sex and residential location in individuals with schizophrenia might be one of several contributing factors to the unique epidemiological pattern of schizophrenia in China.

Similar to the general population, the suicide rate in rural residents with schizophrenia was 3.18-fold higher than in urban residents with the illness, but unlike suicide in the general population, the rural versus urban difference in suicide rates was much greater in men than in women with schizophrenia.

However the proportion of people with schizophrenia who committed suicide was higher in urban areas than in rural communities.

"Our high estimate of annual suicide deaths of people with schizophrenia in China indicates this is a major public-health problem for the country that will require development of suicide-prevention strategies specifically designed for people with schizophrenia," commented Phillips.

Differences in demographics between location and gender clearly affect the suicide rate, as do other mental illnesses, or the lack thereof.

"This difference has important implications for clinicians who need to identify high-risk patients and for public-health officials aiming to reduce the health burden of suicide," he said.

(China Daily October 9, 2004)