ANTI-DRUG workers in Hong Kong should pool their experiences with counterparts on the mainland because the drugs problems in each place are so similar, a regional drugs conference was told yesterday. Professor Chen Char-nie, of the Department of Psychiatry of the Chinese University, said: 'We are chosen as the host place because we have a similar scenario on drug abuse and Hong Kong has well-established expertise in tackling the problem. 'The drug abusers on the mainland start with lighter drugs and later switch to injection, a pattern which is similar to Hong Kong,' he said. He was speaking at the second course on drug prevention and rehabilitation, sponsored by the World Health Organisation's Western Pacific Regional Office and hosted by the Chinese University. Talks as wide-ranging as regional pattern of drug abuse, outreach or self-help rehabilitation programmes and relationship between drug abuse and HIV infection, will be studied by 20 participants from China and two from Macau during the 10-day event. Hong Kong has 10 observers. Meanwhile, Professor Chen, who is also the chairman of the Action Committee Against Narcotics, attributed the decrease of new drug abusers in the first six months of this year to effective preventive education. Figures showed the new cases of male drug abusers shrank to 1,688 from 2,156 in the same period in 1994. Those of female abusers decreased from 521 to 453.