A psychiatrist specializes in the prevention, diagnosis, and treatment of mental, behavioral, addictive, and emotional disorders such as schizophrenia and other psychotic disorders, mood disorders, anxiety disorders, substance-related disorders, sexual and gender identity disorders, and adjustment disorders. They understand the biological, psychological, and social components of illness. Most psychiatrists use some form of discussion (individual or group therapy, psychoanalysis, or behavior modification) to evaluate and treat problems, in addition to using pharmacological treatments. Psychiatrists generally use a holistic approach, since every aspect of humans affects their psychology. They work with individuals and families who are coping with stress, crises, or other problems. They need to use their entire base of knowledge and values when assisting and treating their patients.