If you are one of those who send excessive emails and text messages, then chances are that you are suffering from a mental illness, according to a new research.

The new research suggests that people, who leave office only to log on to their PCs as soon as they reach home, could be suffering from another form of mental illness.

The article, by Dr Jerald Block, said there were four symptoms: suffering from feelings of withdrawal when a computer cannot be accessed; an increased need for better equipment; need for more time to use it; and experiencing the negative repercussions of their addiction.

Block said that although text messaging was not directly linked to the Internet, it was a form of instant messaging and needed to be included among the criteria.

'The chief reasons I see to consider it are motor vehicle accidents that are caused by cell phone instant messaging, stalking and harassment via instant messaging, and instant messaging at social, educational, (and) work functions where it creates problems,' News.com.au quoted him, as saying.

'It should be a pervasive and problematic pattern, though, not isolated incidents,' Block added.

The study is published in American Journal of Psychiatry.