[Psychiatric aspects of multiple chemical sensitivity (MCS)]

Patients with multiple chemical sensitivity (MCS) react to low levels of common environmental chemicals with various health complaints. The etiology and pathogenesis of MCS is not clear. Objective criteria for diagnosis are lacking. Usually there are no pathological somatic findings, while psychiatric morbidity is considerably high. Somatoform, mood and anxiety disorders are diagnosed most frequently. A subgroup of MCS patients may suffer from a special form of somatoform disorders related to the environment. Critics of a psychogenic model of MCS argue that psychiatric diagnoses are descriptive, and causality can not be derived from them. However, clinicians are expected to evaluate the most probable cause of the complaints and give therapeutic recommendations. There are promising therapeutic concepts for somatoform and other psychiatric disorders, but not for MCS. Double-blind challenge tests, but also therapy evaluation studies could contribute to a better understanding of the pathogenesis of MCS in the future.