The world’s largest study into the effectiveness of antidepressants has shown that the drugs really do work.
Trials of 21 commonly-used antidepressants showed that each one was more effective than placebo pills in relieving acute depression in adults.
The meta-analysis used results from almost 120,000 patients across 522 trials.
However, despite the positive outcome of antidepressants overall, the study found large variations in the level of efficacy and side-effects caused by each pill.
The most effective drug was amitriptyline – a drug first discovered in the 1950s.
One of the least effective pills was Fluoxetine – a selective serotonin reuptake inhibitor (SSRI) commonly known as Prozac.
However, research leader Andrea Cipriani of Oxford University struck a note of caution, warning that antidepressants will not work for everyone. About one third of depressed patients do not respond to medication.
Mr Cipriani also warned that the findings did not mean that antidepressants should always be the first line of treatment.
Other options include talking therapies such as cognitive behavioural therapy and counselling.
It is hoped that the study, which is published in medical journal The Lancet, will help both doctors and patients to make informed decisions about the best medication to take.
Some 300 million people suffer from depression worldwide according to the World Health Organisation, with just one in six people in rich countries getting effective treatment.
That figure drops to one in 27 patients in poor and middle-income countries.
Recent studies suggest that 10% of British adults now take antidepressants, with these findings suggest that millions more could benefit from the drugs.
Most effective antidepressants:
Least effective antidepressants:
Fluoxetine (widely known as Prozac)