In a previous post, I provided a link to a burden-of-disease study recently conducted in Ontario. These studies try to examine conditions that contribute to premature mortality and also to impaired functioning by looking at parameters designed for this purpose (e.g. the Global Burden of Disease Study, see another recent post , uses Disability Adjusted Life Years (DALYs) to account for years lived with disability and premature mortality due to different diseases. The importance of mental illness is seen clearly in such studies since people often develop such illnesses early in their life and the illnesses often persist for many years and has a sustained impact. The Ontario study found that in terms of disease burden (this study didn't use DALYs, but used a related approach) the effect of common mental illnesses was greater than all cancers! A summary has been presented on the CBC website .