A study has established that insulin resistance is associated with symptoms of depression and anxiety. There is a new investigation in mice discovered that metformin, a diabetes medication, can combat the said symptoms.
When a person is diagnosed with diabetes, that individual has a higher risk of experiencing anxiety than healthy people. A study in 2008 showed that there is about 20% higher predominance in people diagnosed with diabetes. Though it’s still unclear how diabetes and pre-diabetes are linked to depression or anxiety, some research has associated insulin resistance with symptoms of mental ailments.
When there is insulin resistance, the body is unable to process glucose correctly. This results in elevated levels of sugar in the blood. There are investigations that have linked insulin resistance to hormonal imbalances in the patient’s brain. This often results in the occurrence of anxiety-like or depression-like symptoms and behaviors. Other research endeavors show that in insulin resistance, Type II diabetes and depression share a physiologic characteristic.
Metformin Brings Out the Happy Hormone
In a study published in The Journal of Neuroscience, the scientists used male mice, which had been fed with high-fat food. This simulated insulin resistance. The researchers noted that the mice exhibited brain changes consistent with the onset of symptoms similar to those of anxiety. The said symptoms are the clearest, early indicators of depression.
The scientists divided the mice into two groups and gave one group fluoxetine (common antidepressant) and metformin (a Type II diabetes medication). Guided by Bruno Guiard, Ph.D., Associate Professor of Neuroscience at the University of Toulouse, the group discovered that metformin decreased the anxiety symptoms in mice. This diabetes medication also increased the serotonin levels in the brain.
Serotonin is a neurotransmitter and hormone that has a significant role in regulating hormones. It is often referred to as the brain’s happiness hormone. Metformin actually elevated the serotonin levels by decreasing the tryptophan that enters the brain. Tryptophan is also an essential amino acid that is usually an important ingredient in producing serotonin. If the brain doesn’t have enough tryptophan, it won’t produce enough serotonin. This would then result in an imbalance in the brain, causing symptoms of depression and anxiety.
With metformin, an increased level of tryptophan to flow throughout the brain, boosting serotonin levels.
Eventually, this would be evident in human subjects as well, further strengthening the concept of metformin as the key to having more of the happy hormone, serotonin.