The literature on the causes of neuropsychological deficits (NDs) in alcoholics is reviewed. It is asserted that NDs are caused not simply by the neurotoxicity of alcohol but by the interrelationships of various factors. NDs might thus reflect problems antecedent to or concomitant with alcoholism and not just the consequences of alcohol use. The family histories of alcoholics have shown that a differential susceptibility to NDs might have a genetic basis. NDs might also be due to the fetal alcohol syndrome. Children who eventually become alcoholics have been shown to be more impulsive and hyperactive than other children, factors related to NDs. There seem to be multiple pathways leading to NDs--two ND syndromes, an acceleration of the normal aging process and an amnesic syndrome, seem to be a consequence of alcoholism. Depression and sociopathy are independently related to both alcoholism and NDs, so causal attributions are difficult to determine. The contribution of head injury to NDs in alcoholics might also be important. NDs in alcoholics suffering from liver disease seem to be caused in part by the liver disease and not the alcoholism per se. Liver disease is also associated with nutritional deficiencies which, in turn, can produce certain NDs. Dysfunction in several neurological mechanisms has been shown to be related to alcohol consumption. However, neuronal metabolism, metabolizing enzymes, membrane permeability, neurotransmitters, endocrine function, cerebrovascular pathology and cerebrospinal pathology have not been found to be related to NDs. The effect of congeners has not been investigated.(ABSTRACT TRUNCATED AT 250 WORDS)