Common therapies reduce depression in diabetics, study finds

The major 12-year study based on a Taiwanese adult population cohort has shown the onset of diabetes increases the risk of mood disorders, mainly depression, by more than two and a half times.

However the study, by researchers from Monash University and the National Health Research Institutes, Taiwan also found when metformin is included in the treatment of diabetes, the incidence of mood disorders was reduced by more than 50 per cent.

Metformin is the most commonly used medication for type 2 diabetes. Taken orally, it helps control blood sugar levels.

Lead author, Emeritus Professor Mark Wahlqvist from Monash University's Department of Epidemiology and Preventive Medicine and the Monash Asia Institute, said the increasing prevalence of diabetes is revealing complications beyond the well-known ones affecting the cardiovascular system, the eyes, peripheral nerves and feet.

"In earlier research we found that dementia and Parkinson's disease, the most common forms of known neurodegenerative disease, are more likely after the onset of diabetes," Professor Wahlqvist said.

"The same appears to be so for mood disorders including all forms of depression. We found depression and diabetes are more likely to occur together than would be expected from their respective separate prevalences."

The researchers found the risk of all mood disorders, dementia and Parkinson's disease were reduced by metformin, especially when used with a sulfonylurea drug, commonly used to stimulate the beta cells to produce more insulin, as treatment.

"It is possible that neurodegenerative processes are at work in diabetes-associated depression and that the use of metformin may minimise this risk," Professor Wahlqvist said.

"As the global burden of diabetes to health care systems increases, these findings may be relevant to the reduction of mental health complications associated with diabetes."

The findings of this research was published in BioMed Central's open access journal BMC Medicine today.

Journal reference: BMC Medicine

Provided by Monash University