A search in MEDLINE (1966 – last update May 2006) was made to find epidemiological studies on the association between schizophrenia and physical illnesses. A broad search strategy had to be used to ensure that no physical illness had been missed. For this reason the MeSH term for schizophrenia was combined with the 23 MeSH terms for the general disease categories of physical diseases. If the search had been performed for each individual physical disease alone, some diseases could have easily been missed. These MeSH terms were:

• Bacterial Infections and Mycoses

• Virus Diseases (+ HIV)

• Parasitic Diseases

• Neoplasms

• Musculoskeletal Diseases

• Digestive System Diseases

• Stomatognathic Diseases

• Respiratory Tract Diseases

• Otorhinolaryngologic Diseases

• Diseases of the Nervous System: autoimmune diseases of the nervous system, autonomic nervous system diseases, central nervous system diseases (brain diseases, CNS infections, encephalomyelitis, high-pressure neurological syndrome, meningitis, movement disorders, ocular motility disorders, pneumocephalus, spinal cord diseases), chronobiology disorders, cranial nerve diseases, demyelinating diseases, nervous system malformations, nervous system neoplasms, neurocutaneous syndrome, neurodegenerative diseases, neurologic manifestations, neuromuscular diseases, neurotoxicity syndromes, sleep disorders, trauma, nervous system

• Eye Diseases

• Urologic and Male Genital Diseases

• Female Genital Diseases and Pregnancy Complications

• Cardiovascular Diseases

• Hemic and Lymphatic Diseases

• Congenital, Hereditary and Neonatal Diseases and Abnormalities

• Skin and Connective Tissue Diseases

• Nutritional and Metabolic Diseases

• Endocrine Diseases

• Immune System Diseases

• Disorders of Environmental Origin

• Animal diseases

• Pathological Conditions, Signs and Symptoms.

All abstracts found were read, and potentially relevant articles were ordered for more detailed inspection. The first search was made in autumn 2004; an update search was made in May 2006. The search was complemented by relevant articles mentioned in the studies and other reviews identified.