Reviews have established that people with schizophrenia die 15 years younger than the general population on the average. However, unnatural causes (suicide and accidents) account for only 40% of the excess mortality; the rest is due to physical illnesses. While a number of reviews on the excess mortality exist, (Brown 1997, Harris and Barrowclough 1998), comprehensive reviews on physical comorbidities of people with schizophrenia are not available. Such a review could be important since comorbidity studies examine the risk at a stage when interventions are still possible. We have attempted to fill this gap by providing a review of the association between schizophrenia and physical illnesses using a systematic search strategy.

A MEDLINE search was conducted by combining the MeSH term of schizophrenia with the terms of the 23 general physical disease categories listed by MeSH (first search November 2004, last update May 2006). The search was complemented by cross-referencing of identified studies. Furthermore, a number of experts in the various areas were contacted to obtain information on missing studies. There were no language restrictions. Due to the considerable heterogeneity of the overall study quality in the different areas it was not possible to apply unique inclusion and exclusion criteria. Thus, in well studied areas only population-based, controlled studies were selected, while in other areas studies of lower quality were also included to indicate important future research directions.