A system and method provides closed-loop sedation, anesthesia, or analgesia by monitoring EEG and automatically adjusting the delivery of sedative, anesthetic, and/or analgesic drugs to maintain that desired or predetermined level of cortical at all echelons of care. The system and method further monitor the subject's cortical activity to detect occurrence of burst suppression which can be indicative of unsafe depth of anesthesia or sedation. Further, the system and methods provide for alteration or cessation of the administration of anesthesia or sedation based on the occurrence of burst suppression to mitigate harm to the subject.