London - Millions are taking antidepressants which do little to lift their mood, a major study has revealed.
Sertraline – the most common antidepressant - was found to have few benefits when tackling symptoms such as suicidal feelings, trouble concentrating and poor sleep.
However, a clinical trial said the drug does help relieve feelings of anxiety, including worry and restlessness – which in turn improves overall mental health.
The authors said they were shocked by the "unexpected" findings, but added: "There is still a benefit. Antidepressants work, but in a different way than we thought."
The trial by University College London, published in The Lancet, is the largest of its kind to examine the effectiveness of antidepressants. It found no evidence of a reduction in patients’ symptoms of depression after six weeks on sertraline, and only a "modest" improvement after 12.