In its mildest form, serotonin toxicity is probably relatively common but is often unreported.[2]Buckley NA, Dawson AH, Isbister GK. Serotonin syndrome. BMJ. 2014;348:g1626
http://www.ncbi.nlm.nih.gov/pubmed/24554467?tool=bestpractice.com
[3]Isbister GK, Buckley NA. The pathophysiology of serotonin toxicity in animals and humans: implications for diagnosis and treatment. Clin Neuropharmacol. 2005;28:205-214.
http://www.ncbi.nlm.nih.gov/pubmed/16239759?tool=bestpractice.com
In addition, the ambiguous nature of the Sternbach criteria, a set of criteria that has been used to define serotonin toxicity for many years, means that many other medical conditions were often misdiagnosed as serotonin toxicity, despite the Sternbach criteria requiring the absence of other causes.[3]Isbister GK, Buckley NA. The pathophysiology of serotonin toxicity in animals and humans: implications for diagnosis and treatment. Clin Neuropharmacol. 2005;28:205-214.
http://www.ncbi.nlm.nih.gov/pubmed/16239759?tool=bestpractice.com
[8]Isbister GK, Hackett LP, Dawson AH, et al. Moclobemide poisoning: toxicokinetics and occurrence of serotonin toxicity. Br J Clin Pharm. 2003;56:441-450.
http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2125.2003.01895.x/full
http://www.ncbi.nlm.nih.gov/pubmed/12968990?tool=bestpractice.com
[9]Sternbach H. The serotonin syndrome. Am J Psychiatry. 1991;148:705-713.
http://www.ncbi.nlm.nih.gov/pubmed/2035713?tool=bestpractice.com
There are limited data on the current incidence of serotonin toxicity. Unintentional and intentional exposures to serotonergic drugs are a significant cause of morbidity and mortality in the US. The US National Poison Data System reported over 130,000 exposures to antidepressants in 2020, representing 5.4% of reported cases.[10]Gummin DD, Mowry JB, Beuhler MC, et al. 2020 Annual report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 38th annual report. Clin Toxicol (Phila). 2021 Dec;59(12):1282-501.
http://www.ncbi.nlm.nih.gov/pubmed/34890263?tool=bestpractice.com
Selective serotonin-reuptake inhibitors (SSRIs) and serotonin-noradrenaline reuptake inhibitors (SNRIs) were in the top 25 categories associated with the largest number of fatalities.[10]Gummin DD, Mowry JB, Beuhler MC, et al. 2020 Annual report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 38th annual report. Clin Toxicol (Phila). 2021 Dec;59(12):1282-501.
http://www.ncbi.nlm.nih.gov/pubmed/34890263?tool=bestpractice.com
A number of Australian studies on deliberate self-poisoning found the frequency of adverse effects in SSRI overdoses to be about 15% and the number of severe serotonin toxicity cases to be decreasing.[4]Dunkley EJ, Isbister GK, Sibbritt D, et al. The Hunter Serotonin Toxicity Criteria: simple and accurate diagnostic decision rules for serotonin toxicity. QJM. 2003;96:635-642.
http://qjmed.oxfordjournals.org/content/96/9/635.full
http://www.ncbi.nlm.nih.gov/pubmed/12925718?tool=bestpractice.com
[8]Isbister GK, Hackett LP, Dawson AH, et al. Moclobemide poisoning: toxicokinetics and occurrence of serotonin toxicity. Br J Clin Pharm. 2003;56:441-450.
http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2125.2003.01895.x/full
http://www.ncbi.nlm.nih.gov/pubmed/12968990?tool=bestpractice.com
[11]Isbister GK, Bowe SJ, Dawson A, et al. Relative toxicity of selective serotonin reuptake inhibitors (SSRIs) in overdose. J Toxicol Clin Toxicol. 2004;42:277-285.
http://www.ncbi.nlm.nih.gov/pubmed/15362595?tool=bestpractice.com