Somatoform disorders are characterized by the presence of physical signs or symptoms without medical cause. In addition, they are not willfully produced by the individuaL The somatoform disorders are listed and defined in Table 9-3 (adapted from DSM-IV).

Somatization Disorder
Somatization disorder is diagnosed when an individual has multiple medical complaints that are not the result of medical illness. The specific DSM-IV criteria are narrow and specific, requiring

• Pain in four different body sites or involving four different body functions;
• Two gastrointestinal symptoms (other than pain);
• One sexual symptom (other than pain); and
• One pseudoneurologic symptom (other than pain).

In addition, some symptoms must have begun before age 30 and persisted for several years. Individuals with somatization disorder often have a history of complex medical and surgical treatments that may actually lead to iatrogenic complications of treatment. Patients with somatoform disorder frequently have multiple physicians, make frequent office and hospital visits, and may seek disability because of their conviction that they are severely and chronically medically ill.

This disorder is more common in females (approximately 80% of cases), and its incidence is increased in first-degree relatives of those with somatization disorder. Familial and genetic studies have also shown that male relatives of individuals with somatization disorder have an increased incidence of antisocial personality disorder (ASP) and substance abuse. Adoption studies suggest genetic influences in this disorder.

Various theories have been proposed to explain this disorder. Early psychoanalytic work focused on repressed instincts as causative; more modern theorists propose that somatization symptoms may represent a means of nonverbal interpersonal communication. Biologic findings have revealed abnormal cortical function in some individuals with this disorder.