Controversy surrounds the origin of symptoms attributed to environmental pollutants or widely used chemicals, and the authors believed that a psychiatric evaluation could advance understanding of this contentious condition. They assessed psychiatric morbidity, somatization, and self-attentiveness in patients seen in their Environmental Clinic. Two hundred ninety-five consecutive patients underwent SCID-I and -II interviews and were investigated with self-rating scales for self-attentiveness and somatization. The authors found a high prevalence of mental disorders (66% had a current SCID diagnosis, and 75% had a lifetime SCID diagnosis) and a low level of self-attentiveness, which was not necessarily associated with psychiatric disease. Among patients visiting an Environmental Clinic, mental disorders were common and needed to be diagnosed and treated by standard interventions. Patients who did not meet diagnostic criteria for a psychiatric disorder had relatively low somatization scores and low private self-attentiveness. These "externalizers" could benefit from an intervention that teaches them to focus on their internal and emotional lives. In these patients, the authors consider low self-attentiveness a major feature that may act as a pathogenic factor for environmental illness.