The most common method of administration of morphine in clinical settings is injection for preoperative sedation, as a supplement to anesthesia, and for analgesia.
Antidepressant withdrawal symptoms and their widespread recurrence, even when individuals step down their dose very gradually, is caused by the receptors in the serotonin system experiencing the drop in serotonin to pre-drug levels as starvation.
Withdrawal from benzodiazepines or alcohol can result in seizures and worse if not handled in an in-patient setting.
There have been several deaths caused by PMA, a potent and highly neurotoxic hallucinogenic amphetamine, which is solicited and sold as Ecstasy.