What can cause serotonin syndrome in a newborn?

See below: In a newborn, the only possibility is medicines in the mother at high doses prior just prior to birth. Antidepressants, pain relievers like demerol, (meperidine hydrochloride) ultram, flexeril, saint john's wort, medicines for migraines like "triptans", or street drugs like ecstasy, Cocaine and amphetamines can all cause the syndrome. So if the mom was on any of these prior to birth, the syndrome could occur.

Medications: the mother is taking or the drugs such as cocaine the mother is using.