Opportunities that have come with two decades of economic boom and open markets have also brought more job anxiety, higher expectations and more pressure to achieve, mental health experts said.
India has some of the world's highest suicide rates, with many believing the biggest risk group to be rural farmers facing debt after poor harvests.
However, the study - published in the Lancet medical journal on Friday - says suicide rates are highest in the 15-29 age group, peaking in southern regions that are considered richer and more developed with better education, social welfare and health care.
That puts the young at high risk - a new phenomenon experts said has happened recently as more middle-class youths strive to meet achievement expectations, and new technologies like cell phones and social networking sites help break down traditional family units once relied on for support.
Overall, the report uses a national government survey of deaths in 2001-03 to estimate 187,000 suicides took place in 2010, making it the cause of 3 per cent of deaths that year.
The WHO reports about 1 million suicides a year, which would be a rate of about 14 per 100,000 in a global population of 7 billion. By comparison, the U.S. had 37,790 suicides in 2010, or a rate of 12.2 per 100,000, while India's rate under the Lancet's projected suicide tally of 187,000 would be near 16 - far higher than earlier reports and estimates of around 10.
There has been little scientific examination of suicide motives in India.
While The Lancet study does not address the question of motivation, the report's authors, as well as experts not associated with the study, saw few likely reasons for the rise in suicide among young people beyond the increased pressure that has come with new economic opportunity and social fragmentation.
The higher rates may come from "the greater likelihood of disappointments when aspirations that define success and happiness are distorted or unmet by the reality faced by young people in a rapidly changing society," said Dr. Vikram Patel, one of the report's authors, in an editorial printed in The Hindu.
He also noted online social networking was making "loneliness more common." He admits his conclusion is conjecture, but says "I cannot think of any more plausible explanation."
Among men, 40 per cent of suicides were among people age 15-29. For women, it was nearly 60 per cent.
The revelation has shocked many in a country notorious for poor maternal health care statistics.
"We can only guess broadly at what might be behind it. People say partially the rapid changes on society that have come with globalization, the breakdown of the families," said Dr. Roy Abraham, president of the Indian Psychiatric Society.
There are few facilities in India for mental health problems, and stigmas prevent many people from seeking support. Telephone help lines are often not adequately staffed, and many schools do not have counsellors.
"Mental health is not a priority in India," he said. "It has to be a priority. Many people are not aware of the fact that mental health is behind suicide."
Courts are starting to mandate programs for educating people about public health issues including suicide, sexuality and drug abuse, experts said.
"The young face very high competition and pressure from families to succeed. Many parents think their child should come first in the class. Of course, that can't happen," said Dr. T.S. Sathyanarayana Rao, head of psychiatry at J. S. S. Medical College & Hospital in Mysore, 140 kilometers (87 miles) from the nation's technology centre of Bangalore.
When youths start to despair, they often don't think to seek help, or shun the idea because "they think psychiatry is only for crazy people," he said.
Many suicide cases still go unreported, expert said, as people hide what is still an illegal act in India, the report says.
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