The authors review the vast literature on anxiety disorders and present clear synopses of the major psychiatric approaches to them. Biological vulnerability seems to play an important role in the genesis and perpetuation of these disorders. This theory has been credibly demonstrated for the panic disorders, and preliminary investigations suggest it may be applicable to generalized anxiety disorder and obsessive-compulsive disorder as well. When the biological defect is central, it may manifest itself in pathological learning and in impairment of the mechanisms that regulate anxiety. A variety of psychological treatments, including education, psychotherapy, and behavior and cognitive therapies, have proved useful in these disorders. The authors note the importance of therapeutic inquiry into the patient's history. Medication is indicated to prevent pathological sequelae of anxiety attacks, and seems particularly useful for patients who have a positive family history and spontaneous attacks without apparent internal or external precipitating factors.