London, Feb 24 (IANS): In what could put to rest considerable doubts raised over the effectiveness of antidepressants, a new study has found that many of such pills actually work quite well in adults.

The research, published in the journal Lancet, involved a comparison of more than 20 commonly used antidepressants.

It found all of them to be more effective than placebo for the short-term treatment of acute depression in adults, with effectiveness ranging from small to moderate for different drugs.

"Our findings are relevant for adults experiencing a first or second episode of depression -- the typical population seen in general practice," said lead author Andrea Cipriani from University of Oxford in Britain.

An estimated 350 million have depression worldwide.

The findings of the new study are based on more than 500 trials done between 1979 and 2016 comparing 21 commonly used antidepressants.

A total of 8,7052 participants had been randomly assigned to receive a drug, and 2,9425 to receive placebo. The majority of patients had moderate-to-severe depression.

All 21 antidepressants were more effective than placebo, the study said.

"Antidepressants can be an effective tool to treat major depression, but this does not necessarily mean that antidepressants should always be the first line of treatment. Medication should always be considered alongside other options, such as psychological therapies, where these are available," Cipriani said.