What is serotonin syndrome - a complication of the treatment of depression with drugs with a serotonin mechanism of action, especially from the group of so-called SSRIs. SSRIs(selective serotonin reuptake inhibitors ), but also in combination treatment of SSRIs with TLGCFs (tricyclic antidepressants), SNRIs (serotonin norepinephrinereuptake inhib itors), MAOs (monoamine oxidase inhibitors - an enzyme that inactivates serotonin).