Alcoholics may have additional problems that compound the alcohol issue. Drugs, both prescription and illegal, may cause a synergistic effect in which the overall whole effect of the combined substances is greater than the sum of the parts. This, of course, can have devastating, even fatal, consequences. Psychological problems ranging from depression to schizophrenia are often seen in the alcoholic. These people may attempt to self-medicate with alcohol, not realizing that alcohol may exacerbate the symptoms of their mental illness.