'How Sertraline feel-good hormone serotonin makes you far better dealing with bad news'

Dr Miriam Stoppard shares surprising research from Oxford University that shows why antidepressants that change serotonin levels are so effective for many mental illnesses, including depression, anxiety and OCD

Most of us have heard of serotonin being referred to as the “feel-good” hormone, and some of us will be familiar with a group of drugs called SSRIs used for the treatment of depression. They work by raising serotonin levels in the blood. But it turns out there’s a lot more to serotonin than that.

Scientists at Oxford University’s Department of Psychiatry have found people with raised serotonin levels have less sensitivity to disappointment (for example, losing money in a card game) without losing sensitivity to reward.

Furthermore, they found that increasing serotonin levels made people better able to control their behaviour, particularly when getting bad news. The study also showed that elevated serotonin levels benefit different types of memory.

Michael Colwell from Oxford’s Department of Psychiatry, the lead author of the report, said: “These findings shed new light on how serotonin shapes human behaviour, particularly in negative environments. We believe it may offer important insights into the cause and treatment of depression.”

Instead of using traditional antidepressants (SSRIs, selective serotonin reuptake inhibitors) in tests, the researchers used a new technique to test the effects of serotonin – a selective serotonin releasing agent, a drug currently used to treat a rare form of epilepsy called Dravet Syndrome.

This novel drug directly increases serotonin levels in the brain.

The study involved 26 participants who were given the drug to increase serotonin, with a further 27 in a control group, who were asked to do a series of tasks measuring learning and behavioural control.

Catherine Harmer, Professor of Cognitive Neuroscience at Oxford University, explained: “Despite nearly a century of research, our understanding of how serotonin influences human behaviour has remained unclear and controversial. This provides us with some exciting new information about the role of serotonin in humans.

“It shows that serotonin, which has been implicated in depression and in the effects of antidepressants, has more of a role in processing negative things, rather than boosting positive responses.

“Serotonin is often referred to colloquially as the ‘happy chemical’ but perhaps it is time we thought of it as the ‘not-so-bad chemical’.”

Associate Professor at Oxford University, Susannah Murphy, added: “By directly manipulating levels of serotonin in the brain, this study helps us to understand some of the core functions this brain chemical plays.

“Our findings underscore the central role that serotonin plays in effortful cognitive processes, such as our ability to put the brakes on unwanted behaviours. This study helps to further understand why drugs that change serotonin levels are effective treatments for many mental illnesses, including depression, anxiety and obsessive-compulsive disorder.”