The findings centre around Ontario, but are nationally representative, say the authors of the report from the Institute for Clinical Evaluative Sciences (ICES) and Public Heath Ontario.
"We calculated the burden of selected mental illnesses and addictions in Ontario by looking at their impact on early deaths as well as on the quality of life. In many cases this burden is substantially more than that of other illnesses such as cancers and infectious diseases," said Sujitha Ratnasingham, lead author and epidemiologist at ICES.
This high burden stems from three factors: Mental illness tends to emerge early in life, it's widespread and it lasts a long time.
Mental illness tends to rear its head during major life transitions like graduating high school, going to college and university, entering the workforce or getting married. This ill timing takes a huge toll on people and society as a whole, the report notes.
People suffering from mental illness can die young and have trouble socializing, or pursuing education and employment.
The five conditions found to have the greatest burdens are depression, bipolar disorder, alcohol use disorders, social phobia and schizophrenia.
Alcohol abuse accounted for 88% of all deaths attributed to mental illness and 91% of years lost due to early death.
"This report tells us that mental health and public health practitioners, policy-makers and researchers need to work together to identify and enhance health promotion and intervention strategies for the population at large, while improving access to treatment for those suffering from mental illness and addictions," said Dr. Vivek Goel, president and CEO of Public Health Ontario.