People who have depression are more likely to develop type 2 diabetes if they also possess metabolic risk factors, a new Canadian study suggests.  

Type 2 diabetes, a metabolic syndrome involving insulin resistance, has long been associated with hypertension, obesity, abnormal blood sugar levels, and high cholesterol, which are all considered as metabolic risk factors.

However, a research by l'Université de Montréal, McGill University, University of Calgary, and the Institut de recherches cliniques de Montréal shows that if a person has these metabolic conditions and depression, the likelihood of diabetes can go as high as six times than those who don't have any of these symptoms. People who have metabolic conditions but don't have depression have an increased type 2 diabetes risk of only four times.

Interestingly, people with depression but without metabolic risk factors are no different from the general population when it comes to developing diabetes.

This simply means that "focusing on depression alone might not change lifestyle/metabolic factors," said Prof. Norbert Schmitz, lead author.

Nevertheless, the study also emphasizes the "vicious cycle" that connects metabolic risk factors, which increase the risk of type 2 diabetes, with depression, which is sometimes blamed on the Neanderthal DNAs.

A person diagnosed or showing signs of depression is less likely to seek treatment or follow doctor's advice on their metabolic conditions, such as obesity or hypertension. If these are left untreated or mismanaged, they can worsen the symptoms associated with depression. Certain antidepressants may also cause weight gain.

The study published in Molecular Psychiatry then suggests that "early identification, monitoring and a comprehensive management approach of both conditions might be an important diabetes prevention strategy."

For the study, the researchers worked with 2,525 men and women with ages between 40 and 69 years old who were living in Quebec at the time of the study, which spanned for four and a half years.

The participants were classified into four groups, with one being the reference. Another group was composed of people who had depression and certain metabolic symptoms while the other two were diagnosed with either depression or metabolic risk factors.