Animal models are important tools in the study of psychiatric disorders, including alcoholism, because they allow the use of research methods that cannot be used for ethical reasons in humans. Consequently, scientists have developed numerous approaches to evaluate the validity and reliability of animal models for studying human behavior and human disorders. Researchers have developed animal models of schizophrenia, fear and anxiety, depression, and alcoholism, all of which are being used to study the relationship between alcoholism and co-occurring psychiatric disorders. These models may help researchers and clinicians determine how best to treat patients with alcoholism and co-occurring psychiatric disorders.