Yokohama, Japan ? The world’s leading psychiatric association decided Monday to look into reports that China is silencing political dissidents by confining them to mental wards, where some are drugged or undergo electric shocks.

The World Psychiatric Assn. voted to send a fact-finding team to China, a move that could lead to Beijing’s expulsion from the professional brotherhood if it resists the investigation as it has other similar missions in the past.

The group said that among those reportedly detained in mental hospitals are nearly 500 members of Falun Gong, a spiritual sect outlawed by China in 1999 for allegedly threatening national security.

“We are concerned they have Falun Gong members who are not patients in their hospitals,” outgoing association president Juan Lopez-Ibor told the World Congress of Psychiatry, gathering Monday in the Tokyo suburb of Yokohama.

“I am concerned about the abuse of psychiatry,” he said.

In some cases, individuals without mental problems allegedly have been forced to take psychiatric drugs and given electroshock treatment, sometimes as punishment for their political views, the association said, citing reports from international nonprofit organizations and family members.

Chinese officials vehemently deny holding political opponents in mental institutions. But part of China’s effort to crush the Falun Gong group has been a propaganda campaign that often uses gruesome photos and accounts of how suspected members went insane and hurt themselves or others.

Similar charges of psychiatric abuse led the Soviet Union to withdraw from the World Psychiatric Assn. in 1983 as the other members prepared to expel them. Soviet psychiatrists were readmitted in 1989 after doctors there released hundreds of dissidents.

In its vote Monday, the association which represents professional groups from 105 nations said it wanted to inspect China’s hospitals by May after working out ground rules with Chinese authorities.