A commonly-prescribed antidepressant reduces anxiety first and has a smaller effect on depressive symptoms weeks later, a study suggests.
Researchers at University College London said it made people feel better but worked in unexpected ways.
Their trial involved 653 UK patients, half of whom were given sertraline and the other half a placebo (dummy pill).
Psychiatrists say the findings are reassuring for doctors and patients, confirming the benefits of treatment.
Read more on BBC News website.