This is any condition in which the main influencing factor is morphine, the main alkaloid of opium that is a highly potent opiate analgesic psychoactive drug. Morphine acts directly on the central nervous system (CNS) to relieve pain but has a high potential for addiction, with tolerance and both physical and psychological dependence developing rapidly. Morphine is the most abundant opiate found in Papaver somniferum (the opium poppy).