Study finds first direct evidence of a link between low serotonin and depression

Exclusive: Findings add weight to view that decreased serotonin response could play an important role in depression

Scientists claim to have found the first direct evidence that people with depression have a reduced capacity for releasing serotonin in the brain.

The findings from a brain-imaging study reignite a debate within psychiatry over the so-called serotonin hypothesis of depression and challenge the conclusions of an influential review published in July that found no clear evidence" that low serotonin levels are responsible. The latest work, led by scientists at Imperial College London, suggested that people with depression have a decreased serotonin response.