High rates of major depressive disorder occur in heavy drinkers. Whether it is more true that major depressive disorder causes self-medicating alcohol use, or the increased incidence of the disorder in people with an alcohol use disorder is caused by the drinking, is not known though some evidence suggests drinking causes the disorder. Alcohol misuse is associated with a number of mental health disorders and alcoholics have a very high suicide rate. A study of people hospitalised for suicide attempts found that those who were alcoholics were 75 times more likely to go on to successfully commit suicide than non-alcoholic suicide attempts. In the general alcoholic population the increased risk of suicide compared to the general public is 5-20 times greater. About 15 percent of alcoholics commit suicide. Use of other illicit drugs is also associated with an increased risk of suicide. About 33 percent of suicides in the under 35s are correlated with alcohol or other substance misuse.