Adult Outpatient Psychiatrist A psychiatrist specializes in the prevention, diagnosis and treatment of mental, addictive and emotional disorders such as schizophrenia and other psychotic disorders, mood disorders, anxiety disorders, substance-related disorders, sexual disorders, gender dysphoria and adjustment disorders. A psychiatrist is qualified to order diagnostic laboratory tests and to prescribe medications, evaluate and treat psychological and interpersonal problems and to intervene with families who are coping with stress, crises and other problems in living.