3.2 Epidemiology
The true incidence of serotonin syndrome remains unknown, and the number
of cases is likely significantly higher than reported. The clinical
manifestation of serotonin syndrome varies, and its symptoms can
resemble those of several other medical conditions. Mild cases are
frequently overlooked or dismissed thus making serotonin syndrome likely
to be underdiagnosed in clinical practice 1,4,13. At
the same time, reported cases of serotonin syndrome appears to be on the
rise; likely as a result of the widespread usage of serotonergic
medications, in particular selective serotonin reuptake inhibitors
(SSRIs) 1,11,13–15.
As a rough estimate, the Toxic Exposure Surveillance System, a major US
database, reported 54,410 cases of SSRI poisoning in 2016, with 102
resulting deaths. It is speculated that approximately 15% of these
poisonings meet criteria for serotonin syndrome 11.