Genetic studies of personality traits have provided evidence that temperament dimensions are associated with distinct neurochemical substrates contributing to specific personality phenotypes, and that certain aspects of abnormal emotional traits in alcoholics may be inherited. Additionally, an individual’s genetic history can impact both a tendency toward alcoholism and the development of anomalies in areas of the brain involved in emotional processing, most notably the cerebral cortex, limbic system structures, and the cerebellum. Results of in vivo MRI and post-mortem neuropathological studies of alcoholics indicate that the greatest cortical loss occurs in the frontal lobes, with concurrent thinning of the corpus callosum. Additional damage has been documented for the amygdala and hippocampus, as well as in the white matter of the cerebellar vermis. All of the critical areas of alcoholism-related brain damage are important for normal emotional functioning. When changes occur in these brain regions as a consequence of genetic aberrations or chronic ethanol use, or both, corresponding changes in emotional functions are to be expected. Such changes have been observed in the perception and evaluation of emotional facial expressions, interpretation of emotional intonations in vocal utterances, and appreciation of the meaning of emotional materials.
