Teens who abuse drugs are left with lower mental abilities, with some users functioning at levels classified as mentally retarded, a youth worker group said yesterday after presenting results of a three-year study.
The findings come as police continue their hunt for the dealer who supplied Chek Wai-yin, a 13-year-old girl who collapsed and died after apparently taking Ecstasy and ketamine at a Mongkok disco on Wednesday.
The Hong Kong Playground Association, an outreach group, began a pilot study three years ago. About 350 teenagers and young adults with a history of prolonged drug abuse took part, agreeing to undergo IQ tests and a CT scan to reveal any brain damage when the results indicated poor mental abilities.
Ben Cheung Kin-leung, a doctor from Kwai Ching Hospital who acted as a consultant to the study, said more than 200 of the participants showed low mental ability.
'A significant proportion of the youngsters who went through the tests have shown below-normal mental ability,' Dr Cheung said. Participants with an IQ below 80 were classified as slow learners, he said, and those lower than 70 performed at levels deemed retarded.
'Overseas studies showed soft drug abusers can suffer memory loss and cognitive function impairments, such as a lack of logical thinking and concentration,' he said.
An average IQ is between 100 and 110, but over 80 per cent of the participants tested below this, and most were in the 90s.
Referring to the worst-performing teens, Dr Cheung said: 'They have suffered memory and cognitive functions impairment, and always forget things and lack abilities in logic and concentration.'
Social worker Lee Tak-wai, a spokeswoman for the outreach group, said that CT scans of the teenagers who tested poorly revealed patterns of damage to the brain that were consistent with damage caused by drug abuse.
She warned that teens were increasingly treating drugs as a regular, acceptable pastime. 'They take drugs anywhere, like in fast food restaurants. They just go to the toilet and sniff ketamine and leave,' Ms Lee said. Discos were adding to the problem by turning a blind eye to youngsters who wanted to get in.
According to the study's organisers, after the participants were showed the results of the tests, over half later reduced their drug intake or quit altogether. The group intends to deliver a proposal outlining their success to the government, to obtain funds for similar projects at other outreach groups.
Meanwhile, police are still investigating whether Wai-yin and her friends took the drugs to the Mongkok disco or purchased them inside. She complained of feeling unwell, left and collapsed just before 6.15am. An autopsy would be carried out today.