HTR1A and serotonin syndrome: The pathophysiology of serotonin syndrome involves an overabundance of serotonin, leading to the excessive stimulation of 5-HT1A and 5-HT2A receptors within the central nervous system [5]. Serotonin syndrome is typically a clinical diagnosis based on the patient’s presentation and pertinent history, particularly the pharmacological history of recent use of serotonergic medications.