Insulin resistance, which is a problem with how the body handles blood sugar, often occurs before depression.

Diets high in ultraprocessed foods and sugar are linked to a higher risk of depression.

Cutting ultraprocessed foods has been shown to reduce depression and anxiety.

Stanford’s Dr. Shebani Sethi pioneered metabolic psychiatry, which treats the brain and metabolism together.

For decades, psychiatrists have believed that depression is caused by a deficiency of chemical messengers known as neurotransmitters. A lack of these chemicals has been touted as the cause of depression, and antidepressant medicines were believed to work by increasing them. But about one third of patients with depression don’t respond to conventional antidepressants. This suggests there’s more to this story, and new research suggests that our blood sugar may be a missing piece in the depression puzzle.

Why Your Brain Cares About Blood Sugar

Our brain makes up about 2% of our body weight, but it uses about 20% of our body’s energy. Most of that energy comes from glucose, which is the sugar found in our blood. Our bodies use insulin to move glucose from the blood into our cells. You can think of insulin as a key that unlocks cells so sugar can get in.

But when this system gets overloaded, it causes problems. When we eat food that contains a lot of carbohydrates (e.g. sugars and starches), our blood sugar can shoot up quickly and then crash. Over time, our body needs more and more insulin to get the same results. Eventually our cells can become unresponsive to insulin. This is called insulin resistance, and it can lead to type 2 diabetes.

The Link Between Insulin Resistance and Depression

It has been known for a long time that people with diabetes are twice as likely to be........

© Psychology Today