LOS ANGELES: Scared silly of spiders? Horrified by heights? Terrorized by tight spaces? Play a video game -doctor's orders.

Regular, off-the-shelf computer video games are an effective method of treating people's fears, using a style of therapy that exposes people to what scares them in a controlled setting, according to a new study released on Friday.

The study, published in the October issue of the journal CyberPsychology and Behavior, was conducted at the Universite du Quebec en Outaouais in Quebec, Canada.

The researchers found that PC games that allow users to construct and change game environments, used with a headset that lets wearers simulate virtual reality, were just as effective at stimulating phobic responses as dedicated simulation machines that can cost four times as much.

People with phobias are often treated with exposure therapy, where they gradually spend more and more time in settings that scare them in an effort to reduce the fear response and get them to relax and get over their fright.

The researchers used the game "Half-Life" to create a spider-laden environment for arachnophobic people, and "Unreal Tournament" to simulate heights for acrophobics and tight spaces for claustrophobics.

A group of 13 people with phobias and 13 non-phobic people were tested using the games, a low-end PC and the head-mounted display. They were run through the simulations and then tested on a series of scales to measure their response.

"The results demonstrate that despite their low cost and flexibility, (PC simulators) can be phobogenic," the researchers said. "Moreover, virtual environments derived from games can produce the mid-range levels of anxiety that are most useful in therapy."

The researchers made the environments they used for their study available for download on the university's Web site. (http://www.uqo.ca/cyberpsy/)