Celebrity narcotics addictions are back in the spotlight recently with the arrests in Beijing of Taiwanese actor Coco Sun Hsing and Hong Kong actor Max Mok Siu-Chung for drug abuse April 15.

The arrests are hardly the first time Chinese entertainers’ drug habits have got them into trouble with the law. A Taipei court sentenced Taiwanese actress Xiao Shushen to a year in prison last year after she failed to kick her addiction while on probation. Chinese pop singer Xie Dong was also arrested in Beijing on drug charges in 2007.

Rumor has it this recent spate of illegal drug use involves a network of more than 30 celebrities "masterminded” by mainland pop singer Sun Nan. Police, however, have categorically denied such claims.

Though Sun Nan has publicly declared his innocence, the negative impact of the scandal on both the public and his career will be hard to reverse. Why have so many celebrities chosen to use drugs, degrading their hard-won reputations and threatening their livelihood? Social and psychological experts have their say.