Internet and computer addiction should be recognised as a legitimate side effect of mental illness among adolescents, a psychiatrist has told a national psychiatry congress in Darwin.

For three years, Victorian psychiatrist Dr Soumya Basu has been studying a group of six teenage boys who refused to go to school and played computer games excessively.

He found that all of the boys had a range of mental conditions, like autism spectrum disorder, post traumatic stress disorder, depression and social phobia.

Dr Basu says adolescent Australians often show mental illness through their dependence on computers.

"Unfortunately, computer addiction is not a diagnosis that we can make under the current diagnostic system," he said.

Dr Basu says countries such as Korea and China have begun treating computer addiction as a mental illness, and Australia should do the same.

"It is a routine part of our examination to ask about things like alcohol and cannabis and other things," he said.

"We need to keep this in mind while doing our assessments and we have to keep internet history in mind while seeing young people."