Thus, one may assume that the cases of severe toxicity reported after recreational use of these drugs (e.g. Elliott, 2000; De Letter et al., 2001; Martin, 2001; Lamberth et al., 2008), which resemble “serotonin syndrome” symptoms (Lapoint et al., 2013), are related to a sustained increase of synaptic 5-HT and DA resulting from both monoamine reverse transport and MAO-A inhibition. The gene discussed is MAOA; the disease is serotonin syndrome.