A large-scale sample survey was launched in Beijing Tuesday to investigate cases of depressive psychosis.

With the theme of depressive psychosis epidemiology, the special household survey is the first of its kind ever conducted in the capital and will last a month and a half.

The survey staff will select 10,160 households at random and survey a person older than 15 in each selected family, according to the Beijing Mental Health Protection Agency, the organizer of the survey.

The agency will conduct the survey in the manner approved by the World Health Organization. The 70-page survey document includes more than 10 parts, with questions involving smoking, drinking and demography.

The survey would guarantee the privacy of those surveyed, said Guo Hongli, a member of the agency, adding the two parties would have to sign an agreement before starting the inquiry.

"If anyone refuses to be surveyed, we will respect his or her choice and move on to the next family," Guo added.

According to a survey conducted in 1991, more than 100,000 Beijing residents older than 15 were suffering serious depressive psychosis.

(Xinhua News Agency April 2, 2003)