Washington, April 11 : A recent study has found that the internet can accurately identify people's depression.

The study, published in BMC Psychiatry, demonstrates that a Chinese online tool for assessing depression is both precise and reproducible, and may offer a way to recognize the growing number of people suffering from depression.

Chao-Cheng Lin of the National Taiwan University Hospital, Yu-Chuan Li of the National Yang-Ming University, and other colleagues in Taiwan developed the Internet-based Self-assessment Program for Depression (ISP-D).

Between September 2001 and January 2002 the team recruited 579 subjects via a popular mental health website. Volunteers were then sent a follow-up email one to two weeks after completing the first questionnaire inviting them to re-sit the test, and those who completed the questionnaires were offered a psychiatrist's appointment to validate the diagnosis.

Results of the first assessment showed that 31 percent of participants had major depressive disorder, 7 percent a minor depressive disorder, 15 percent had some symptoms of depression that did not amount to a full diagnosis of depression (subsyndromal depressive symptoms) and 46 percent had no depression.

Analyses of the retest results showed outstanding reproducibility for major depressive disorder. The reproducibility was lower for minor depressive disorder, which may be because minor depression is not a stable diagnosis. The psychiatrist's follow-up exposed that the analysis was correct for three-fourths of those tested online.

Around one-fifth to two-fifth of the world's population undergo depression, but most remain unobserved or go untreated, making it essential to offer more opportunities for diagnosis.

"The ISP-D provides a continuously available, inexpensive, and easily maintained depression screening method that is accessible to a large number of individuals across a broad geographic area," write the authors.

This means allows people to consistently gauge depression in themselves on their own and in a short amount of time.