Taken together, EEG findings in line with the Tcor and neurochemical data demonstrated that there are aberrant EEG powers in the serotonin syndrome, supporting the suggestion that environmental conditions have impacts on the activity balance between 5-HT1A and 5-HT2A receptors in adaptation to the drug environment associated with the syndrome intensity in MDMA toxicity. Here, HTR1A is linked to serotonin syndrome.