DIMMED lights, spooky music, the delicious shiver down the spine - it's all part of the fun of reading about ghosts and ghouls. But these days, teenagers' taste for horror stories may give them 'thrills' that will badly disturb their sleep, experts say. For the cause, they point to the recent spate of horror 'comics' featuring gratuitous sex and violence. These comic strips, often filled images of dismembered bodies, killing and rape, are becoming popular with teenagers seeking to escape what they consider to be a mundane school life. Such comics cost between $10 and $30, and a number are based on actual crimes such as the killing of hostages or rapes. Lau Kwok-ying, a 17-year-old commercial studies student, is among those who regularly reads such horror strips. She told Sunday Young Post that she found it hard to resist reading the strips although she realised that they could be damaging. 'I know that I will be disturbed by the disgusting images that keep popping up in my mind at night and I also know that I will have nightmares for a whole week after reading one. But I guess that I can't control myself; the scare makes my dull life a bit more exciting.' The price for the 'excitement' from these tales of terror is the insecurity that Kwok-ying feels whenever she's alone in the dark. In fact, one of those ghost stories, illustrated with graphic images, so affected her that she continued to be haunted by the images years after reading it. Dr Leung Jin-pang, a senior lecturer at the Department of Psychology of Chinese University, said these comic strips could cause young people to develop delusions. 'Teenagers tend to be very curious and apt to be affected by the things that that they hear or read. Delusion will form if youngsters keep on reading these strips without properly discussing the feelings they develop with adults or professionals,' he said. 'Sometimes the need for such spooky excitement grows to the extent that teenagers would find school and homework boring in comparison to ghost story comic strips.' Over time, added Dr Leung, they would get used to the horror strips, begin to feel jaded and start to look for 'higher-level' stimulation elsewhere. Technical institute student Lo Chung-ming, 18, is a good example. After several years of reading horror comics, he said he now had to seek strips with greater impact. 'Japanese ghost story comic strips are what I'm reading now. They have more revealing and better graphics.They have more sex and violent scenes that make the local strips look stupid.' Dr Leung said more attention should be paid to provide young readers with a proper attitude when reading these strips and to encourage them to discuss the contents with parents, teachers or professionals so that they will not form delusions.