Hans Förstl


Multiple Chemical Sensitivity (MCS)

Idiopathic Environmental Illness (IEI)


Psychosom Med. 2006 Jan-Feb;68(1):104-9.

Psychiatric morbidity and toxic burden in patients with environmental illness: a controlled study.

•    Bornschein S,
•    Hausteiner C,
•    Konrad F,
•    Forstl H,
•    Zilker T.
Department of Toxicology, II. Med. Clinic, Technical University of Munich, Munchen, Germany. s.bornschein@lrz.tu-muenchen.de

OBJECTIVE: Patients with environmental illness experience a large number of psychological symptoms. The nature of these symptoms and their pathogenesis (toxicogenic versus psychogenic) is controversial. The objective was to (1) characterize the nature of the psychological symptoms according to well-established diagnostic criteria, and (2) to investigate the association between toxicological factors and psychological symptoms. METHODS: Toxic burden, somatic morbidity, and psychiatric morbidity were assessed in 309 outpatients with environmental illness and 59 semiconductor industry workers matched for age and gender. Psychiatric disorders were assessed by a structured psychiatric interview (SCID), and distress was assessed by the Symptom-Checklist-90-Revised (SCL-90-R). Routine and specific laboratory tests in blood and urine samples were used to assess chemical exposures. RESULTS: Overall psychiatric morbidity was significantly higher in patients than in controls according to SCID (75% versus 24%). Somatoform, mood, and anxiety disorders were significantly more frequent in patients with environmental illness. They also revealed marked stress on the SCL-90-R somatization subscale and scored significantly higher than controls on most of the other subscales. Industry workers from the control group tended to have higher urine metal concentrations than environmental illness patients and similar concentrations of solvents in blood. CONCLUSION: Our data extend previous findings of high psychiatric morbidity in patients with environmental illness. They do not support the notion of a direct causal link between chemical exposure and the psychological symptoms.
PMID: 16449419 [PubMed - indexed for MEDLINE]



J Occup Environ Med. 2006 Jan;48(1):76-82.

New aspects of psychiatric morbidity in idiopathic environmental intolerances.

•    Hausteiner C,
•    Mergeay A,
•    Bornschein S,
•    Zilker T,
•    Forstl H.
Department of Psychiatry and Psychotherapy, Technical University Munich, Munich, Germany. c.hausteiner@lrz.tum.de

OBJECTIVE: To understand idiopathic environmental intolerances (IEI)-formerly multiple chemical sensitivities (MCS)-it is helpful to outline its characteristic psychiatric morbidity. METHOD: We applied a standardized interview according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (SCID) to 305 environmental patients with and without IEI. RESULTS: Somatoform, affective and anxiety disorders were the most frequent diagnoses but only slightly differed between patients with or without IEI. In both groups, current substance-related disorders were rare. We found a clearly higher prevalence of psychotic, especially current delusional disorders, in IEI. CONCLUSION: Somatization, depression, and anxiety are frequent in IEI but nonspecific. Psychotic disorders are more common in IEI than in other types of environmental illness. It appears worthwhile to study personality and cognitive style to explain the pivotal features of IEI.
PMID: 16404213 [PubMed - indexed for MEDLINE]


Int J Hyg Environ Health. 2005;208(4):271-8. Links

Self-reported chemical sensitivity in Germany: a population-based survey.

•    Hausteiner C,
•    Bornschein S,
•    Hansen J,
•    Zilker T,
•    Forstl H.
Department of Psychiatry and Psychotherapy, Technical University of Munich, Germany. c.hausteiner@lrz.tum.de

OBJECTIVES: Environmental clinics are frequented by patients with fears and complaints related to environmental triggers. A dose-independent overreaction to small doses of widely used and generally non-toxic chemicals is referred to as multiple chemical sensitivity (MCS), but no clearly defined clinical syndrome with objective physical findings has been delineated so far. We aimed to obtain information about symptoms, supposed environmental triggers, the frequency of self-reported chemical sensitivity, and of the diagnosis MCS in Germany. METHODS: We conducted a representative survey among 2032 adult Germans. RESULTS: We found self-reported chemical sensitivity in 9% and physician-diagnosed MCS in 0.5% of our representative sample. Physical complaints were common in the whole study population and in chemically sensitive individuals, but there was no clear-cut symptom constellation among the latter. The most common complaints were headache, fatigue, sleep disturbances, joint pain, mood changes and nervousness. A subjective connection between complaints and environmental triggers was denied by 67% of the whole group and by 35% of the self-reported chemically sensitive. Factor analysis of environmental triggers suggested that a specific exposure situation rather than chemical similarity is the basis for individual trigger combinations. CONCLUSIONS: The prevalence of subjective sensitivity towards chemicals is similar to such rates reported from other countries. There is a relatively low awareness of the MCS-concept, and it appears to be diagnosed less frequently than, e.g., in the USA. Since symptoms and triggers in chemically sensitive individuals did not differ from the general population, our data do not suggest the existence of a widespread new syndrome related to chemical sensitivities in Germany. We outline the limitations of self-reported chemical sensitivity as the major criterion for such a contentious diagnosis as MCS.
PMID: 16078641 [PubMed - indexed for MEDLINE]



MMW Fortschr Med. 2003 Aug 21;145(33-34):31-4. Links

[Multiple chemical sensitivity. Is the patient suffering as a result of environmental pollutants or psychological problems?]

[Article in German]
•    Hausteiner C,
•    Bornschein S,
•    Forstl H,
•    Zilker T.
Toxikolog. Abt. der II. Med. Klinik und Poliklinik fur Psychiatrie und Psychotherapie, TU Munchen. c.hausteiner@lrz.tum.de

Multiple chemical sensitivity (MCS) poses a medical challenge. Proposed etiologies are as numerous as they are contradictory, direct and indirect costs are high, and patient suffering considerable. In the absence of objective diagnostic criteria, estimation of its prevalence is difficult. Nevertheless, establishment of the diagnosis is frequently strikingly uncritical. We support an holistic approach that gives consideration both to psychological and physical aspects, as well as taking account of the high level of comorbidity, and we warn against "over-diagnosis". Therapeutical approaches should consider carefully the risk of avoidance and social withdrawal.
PMID: 14526571 [PubMed - indexed for MEDLINE]



J Nerv Ment Dis. 2003 Jan;191(1):50-5.   Links

Psychiatric morbidity and low self-attentiveness in patients with environmental illness.

•    Hausteiner C,
•    Bornschein S,
•    Bickel H,
•    Zilker T,
•    Forstl H.
Department of Psychiatry and Psychotherapy, Technical University Munich, Ismaninger Strasse 22, D-81675 Munich, Germany. Send reprint requests to Dr. Hausteiner. Department of Toxicology, Technical University Munich, Munich, Germany.

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.
PMID: 12544600 [PubMed - indexed for MEDLINE]



Nuklearmedizin. 2002 Dec;41(6):233-9.   Links

PET in patients with clear-cut multiple chemical sensitivity (MCS).

•    Bornschein S,
•    Hausteiner C,
•    Drzezga A,
•    Bartenstein P,
•    Schwaiger M,
•    Forstl H,
•    Zilker T.
Toxikologische Abteilung der II. Medizinischen Klinik und Poliklinik, Technischen Universitat Munchen, Klinikum rechts der Isar, Munchen. sbornschein@lrz.tu-muenchen.de

AIM: Multiple chemical sensitivity (MCS) is a controversially discussed symptom complex. Patients afflicted by MCS react to very low and generally non-toxic concentrations of environmental chemicals. It has been suggested that MCS leads to neurotoxic damage or neuroimmunological alteration in the brain detectable by position emission tomography (PET) and single photon emission computer tomography (SPECT). These methods are often applied to MCS patients for diagnosis, although they never proved appropriate. METHOD: We scanned 12 MCS patients with PET, hypothesizing that it would reveal abnormal findings. RESULTS: Mild glucose hypometabolism was present in one patient. In comparison with normal controls, the patient group showed no significant functional brain changes. CONCLUSION: This first systematic PET study in MCS patients revealed no hint of neurotoxic or neuroimmunological brain changes of functional significance.
PMID: 12520659 [PubMed - indexed for MEDLINE]



Versicherungsmedizin. 2002 Dec 1;54(4):163-7. Links

[Psychiatric aspects of multiple chemical sensitivity (MCS)]

[Article in German]
•    Bornschein S,
•    Hausteiner C,
•    Forstl H,
•    Zilker T.
Toxikologischen Abteilung der II. Medizinischen Klinik und Poliklinik, Klinik und Poliklinik fur Psychiatrie und Psychotherapie, Technischen Universitat Munchen.

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.
PMID: 12491564 [PubMed - indexed for MEDLINE]



Psychol Med. 2002 Nov;32(8):1387-94. Links

Psychiatric and somatic disorders and multiple chemical sensitivity (MCS) in 264 'environmental patients'.

•    Bornschein S,
•    Hausteiner C,
•    Zilker T,
•    Forstl H.
Psychiatric Clinic and Department of Toxicology, I, Medical Clinic, Technical University of Munich, Germany.

BACKGROUND: An increasing number of individuals with diverse health complaints are currently seeking help in the field of environmental medicine. Multiple chemical sensitivity (MCS) or idiopathic environmental intolerances (IEI) is defined as an acquired disorder with multiple recurrent symptoms associated with environmental chemicals in low concentrations that are well tolerated by the majority of people. Their symptoms are not explained by any known psychiatric or somatic disorder. METHOD: Within a 2-year period we examined 264 of 267 consecutive patients prospectively presenting to a university based out-patient department for environmental medicine. Patients underwent routine medical examination, toxicological analysis and the structured clinical interview for DSM-IV psychiatric disorders (SCID). RESULTS: Seventy-five per cent of the patients met DSM-IV criteria for at least one psychiatric disorder and 35% of all patients suffered from somatoform disorders. Other frequent diagnoses were affective and anxiety disorders, and dependence or substance abuse. In 39% a psychiatric disorder, in 23% a somatic condition and in 19% a combination of the two were considered to provide sufficient explanation of the symptoms. Toxic chemicals were regarded as the most probable cause in only five cases. The suspected diagnosis of MCS/IEI could not be sustained in the vast majority of cases. CONCLUSION: This investigation confirms previous findings that psychiatric morbidity is high in patients presenting to specialized centres for environmental medicine. Somatoform disorders are the leading diagnostic category, and there is reason to believe that certain 'environmental' or MCS patients form a special subgroup of somatoform disorders. In most cases, symptoms can be explained by well-defined psychiatric and medical conditions other than MCS, which need specific treatment. Further studies should focus on provocation testing in order to find positive criteria for MCS and on therapeutic approaches that consider psychiatric aspects.
PMID: 12455937 [PubMed - indexed for MEDLINE]



Nervenarzt. 2000 Sep;71(9):737-44.   Links

[Psychiatric and somatic morbidity of patients with suspected multiple chemical sensitivity syndrome (MCS)]

[Article in German]
•    Bornschein S,
•    Hausteiner C,
•    Zilker T,
•    Bickel H,
•    Forstl H.
Klinik und Poliklinik fur Psychiatrie und Psychotherapie, Technischen Universitat Munchen.

Multiple chemical sensitivity (MCS) or idiopathic environmental intolerance (IEI) is understood as an acquired disorder with multiple recurrent symptoms that cannot be traced to any well-known medical or psychiatric condition and is associated with diverse environmental influences that are well tolerated by the majority of people. In a prospective study, we investigated 120 consecutive patients admitted a university-based outpatient department for environmental medicine during 1 year. Apart from routine medical examination and special toxicological diagnostic procedures, a structured clinical interview for DSM-IV psychiatric disorders was performed with every patient. At least one psychiatric diagnosis was found in 100 patients. The diagnostic criteria for somatoform disorders were filled by 53 patients. We found lifetime or current affective disorders in 39 patients, anxiety disorders in 29, and substance dependency or abuse in 25. In 16 patients, personality disorders were diagnosed. Nine suffered from psychotic disorders. This is the largest prospective study with standardized psychiatric diagnostic methods concerning psychiatric morbidity and MCS. The data show that many patients with environmental health problems obviously suffer from somatoform disorders but also from other, well-known psychiatric conditions.
PMID: 11042869 [PubMed - indexed for MEDLINE]



J Intern Med. 2001 Oct;250(4):309-21.   Links

Idiopathic environmental intolerances (formerly multiple chemical sensitivity) psychiatric perspectives.

•    Bornschein S,
•    Forstl H,
•    Zilker T.
Department of Toxicology, II. Medical Department, Technische Universitat Munchen, Germany. s.bornschein@lrz.tu-muenchen.de

Idiopathic environmental intolerances (IEI)/multiple chemical sensitivity (MCS) is characterized by various somatic symptoms which cannot be explained organically, but are attributed to the influences of toxic environmental chemicals in low, usually harmless doses. In the absence of a widely accepted definition of IEI, contradictory aetiological hypotheses and therapeutic suggestions are discussed. Some authors doubt the existence of IEI/MCS as a disease entity of its own. The label IEI does not implicate neither a diagnosis of somatic disease nor that it is caused by an avoidable exposure. Many IEI patients suffer from psychiatric diseases. A majority of them can be diagnosed as somatoform disorders. Consequently, psychiatric therapies could be effective. This review describes the current knowledge about IEI/MCS, outlines a diagnostic algorithm and a psychotherapeutic concept for variants of IEI understood as a somatoform disorder.
PMID: 11576318 [PubMed - indexed for MEDLINE]



Fortschr Neurol Psychiatr. 1999 Apr;67(4):175-87. Links

[Idiopathic environmental intolerance (IPI)--formerly multiple chemical sensitivity (MCS)--from the psychiatric perspective]

[Article in German]
•    Blaschko S,
•    Zilker T,
•    Forstl H.
Klinik und Poliklinik fur Psychiatrie und Psychotherapie, Technischen Universitat Munchen.

The term "idiopathic environmental intolerances" (IEI)/"multiple chemical sensitivities" (MCS) is used to describe a complex of heterogeneous somatic symptoms without a diagnosable organic disease. Symptoms are believed to be triggered by exposure to low levels of environmental chemicals that are usually well tolerated by the general population. There is no widely accepted definition for the phenomenon. A number of contradictory etiologic hypotheses and therapeutic concepts are discussed. One of the crucial questions is whether IEI/MCS should be understood as an own entity of disease. It has been demonstrated that a majority of patients with IEI/MCS meet diagnostic criteria for psychiatric diseases. Most frequently, somatoform, affective and anxiety disorders can be diagnosed. Therefore, psychiatric and psychotherapeutic therapy seems appropriate. The present paper provides a review of the different case definitions, etiologic and therapeutic concepts and of studies examining the frequency of psychiatric morbidity in patients with IEI/MCS. Additionally, a diagnostic algorithm and a concept of behavioral therapy for IEI/MCS patients with somatoform disorders are described.
PMID: 10327313 [PubMed - indexed for MEDLINE]