However, a recent study suggested that although the role of peripheral 5-HT in LC remains uncertain, reduction in platelet 5-HT may be associated with a decrease in cardiovascular sequelae of COVID-19, due to effective inhibition of the platelet serotonin transporter by selective serotonin reuptake inhibitors (SSRIs), and therefore a sharp decline in platelet serotonin is expected, not necessarily associated with cognitive symptoms [72]. Here, HTR5A is linked to COVID-19.