Serotonin is a critical chemical when it comes to a number of psychiatric conditions, such as OCD, where it seems to play a particular role in cognitive flexibility. That is, serotonin levels are related to the fact that someone is perseverating on intrusive thoughts or compulsions and isn’t able to be as flexible as otherwise would be necessary.

Trevor Robbins, professor of cognitive neuroscience at the University of Cambridge, is one of the authors of a recent study titled Comparable roles for serotonin in rats and humans for computations underlying flexible decision-making, and he says such cognitive flexibility also plays a role in depression and schizophrenia.

Read the full study here: https://www.nature.com/articles/s41386-023-01762-6