It used to believed that treatments for migraine would work in menstrual migraine but that has not proven to be the case because menstrual migraines are harder to treat. Because of this, menstrual migraines are now considered a separate medical disorder from migraine. In 2008, menstrual migraines were given ICD-9 codes (346.4-346.43) of their own which separate menstrual migraine from other types of migraine.