A study, in the British Medical Journal, showed a sudden fall in antidepressant prescriptions and a rise in suicide attempts after media reports of the connection.
The team at Harvard Medical School said the unintended effect was “disturbing”.
Experts said similar changes had been seen in other countries.
In 2003, there were concerns about an increased suicide risk from some antidepressants. It led to the US Food and Drug Administration changing the medicine warnings and widespread media reports.
However, there was concern that the reports were exaggerated and missed out the benefits of antidepressants.
The study, which followed 2.5 million teenagers and young adults between 2000 and 2010, showed an immediate impact of the warnings.
Prescriptions fell by a third in teenagers and by a quarter in young adults.
The number of suicide attempts increased by 22% in teenagers and 34% in young adults. Overall it led to an additional 77 attempts, the researchers estimated.
The report concluded: “It is disturbing that after the health advisories, warnings and media reports about the relation between antidepressant use and suicidality in young people, we found substantial reductions in antidepressant treatment and simultaneous, small but meaningful increases in suicide attempts.”
One of the researchers, Prof Stephen Soumerai, said: “This is an extraordinarily difficult public health problem, and if we don’t get it right, it can backfire in serious ways.
“These drugs can save lives. The media concentrated more on the relatively small risk than on the significant upside.”
