Chronic diseases, such as heart disease, stroke, chronic respiratory diseases and diabetes, are by far the leading causes of mortality in the world, representing 60% of all deaths. However, chronic disease rarely exists in isolation. Nevertheless, study of chronic disease rarely takes into account comorbidity and virtually none examine their occurrence in populations.

and aims To review the association between psychiatric disorders and other medical comorbidities.

To study the association between psychiatric diseases and medical comorbidities on a population-scale.

To reconsider our approach to medical comorbidities.

Using an informatics approach, a dataset containing physician billing data for 764 731 (46% male) individuals spanning sixteen fiscal years (1994–2009) in Calgary, Alberta, Canada was compiled permitting examination of the relationship between Physical Disorders and Mental Disorders, based on the International Classification of Diseases (ICD).

All major classes of ICD physical disorders had odd ratios with confidence intervals above the value of 1.0. Ranging from 1.47 (Injury poisoning) to Circulatory systems (3.82). More precisely, when a psychiatric disorder is present, the likelihood to develop one of the four preventable diseases is significantly increased: Stroke (4.27), Hypertension (3.34), Diabetes (2.66) and COPD (2.43).

We postulate that psychiatric disorder should be included in the classification of preventable chronic diseases that have a profound impact on society. Developing a consistent and standardized approach to describe these features of disease has the potential to dramatically shift the format of both clinical practice and medical education.

The authors have not supplied their declaration of competing interest.