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Insulin is even more important to your health than we thought - not only can problems with it cause diabetes, but they can also cause schizophrenia. The good news? This new discovery could lead to treatments for both conditions.

This link was identified in a study conducted by researchers at Vanderbilt University Medical Center, who discovered a definite link between malfunctioning insulin regulation in the brains of mice and increased incidence of schizophrenia-like behavior. It's not just that the same risk factors for diabetes can also lead to schizophrenia; it's that one condition can actually exacerbate the severity of the other from a behavior perspective.

Endocrinologist Kevin Niswender explains that recognition of this link could aid in the development of treatments that better address the multifaceted nature of patients' conditions:
"We know that people with diabetes have an increased incidence of mood and other psychiatric disorders. And we think that those co-morbidities might explain why some patients have trouble taking care of their diabetes."

The group, led by neurobiologist Aurelio Galli, had already that insulin doesn't just regulate glucose metabolism, but it also plays a major role in regulating the supply of the neurotransmitter dopamine to the brain. Problems in dopamine regulation can lead to depression, ADHD, Parkinson's, and schizophrenia. Now they've developed special mice that have helped them determine the precise molecular link between faulty insulin regulation, improper dopamine function, and schizophrenia-like behavior.

They impaired insulin function in mice, but only in their neurons. This allowed them to restrict their analysis purely to the brains of the mice. This impairment led to external behaviors that resembled those of schizophrenia patients, while internally the mice were found to have too little dopamine and too much norepinephrine in the prefrontal cortex, which is a crucial area for cognitive functions.Both of these were the result of an overabundance of the transmitter protein known as NET, which is supposed to help remove these neurotransmitters from the neural synapses.

Galli explains what he thinks is going on:
"We believe the excess NET is sucking away all of the dopamine and converting it to norepinephrine, creating this situation of hypodopaminergia (low levels of dopamine) in the cortex."

Giving the mice drugs that inhibit NET helped bring dopamine levels in the cortex back to normal, helping to also restore the mice to their original behaviors. This success has led to clinical trials in which schizophrenia patients will also be given NET inhibitors in the hopes that it will reduce the severity of their symptoms. This link also points to a very real link between the foods we eat and the moods we feel, and better understanding of the connection between insulin signaling and dopamine regulation could help develop better therapeutic treatments for those with schizophrenia.



No wonder

sugar binges make it hard to control mood. Could perhaps also explain why some people reach for sugar to try to "medicate" low dopamine.

What a discovery...

dealing with diabetics, specially when they get on a downwards spiral in their blood sugar is no fun... Irrational, irritable and nonfunctional is an understatement. My husband woke me at 3 am after not having eaten supper and taking his insulin, telling me he was 'crashing' and he wanted a coffee with sugar. Totally incoherent after that and we were in a hotel room with no food. I happened to have a lollipop which I gave him. I had to take the paper off and tell him what to do with it. I made him a coffee with sugar as he had first requested that, and when I handed him the mug he said, "What am I supposed to do with that? " He did recover quite fast after that and I went to the lobby to get some apples which he by then knew what to do with lol he was all the way down to 50 where he should have been at about 100. You can bet I kept my eye on his eating for the rest of the stay.

But the article does help explain some of the mood issues, what a find... Thanks for sharing Gary!

Flowing Searcher


Some antipsychotic meds increase the chances of developing diabetes, so this study sounds a little funny. It sounds like a way of taking away the blame on the medications. I bet the multi billion dollar making pharmaceutical companies just love this find. Incidentally, how does a mouse behave schizophrenically? Does he refuse to work and pay taxes and pretends to hear voices? Smart freaking mice these days, forget the film Planet of the Apes, lookout it’s Planet of the Mice. Does schizophrenia even exist? I’ve read that mental illness was a fabrication created by the enlightenment to take care of societies socially unacceptable citizens. LOL! It’s all quite sad in my books. Just my thoughts on the subject of vulnerable and exploited human beings (“THE MENTALLY ILL”). :)

All life is sorrowful and the world is an ever burning fire, so enjoy the stately dance of the mystic bliss beyond pain, for that is at the heart of every mythic rite.

Good questions

I asked Gary to post this simply because diet (particularly sugar) seems to have such an impact on people's moods here. I agree that it raises more questions than it answers. But it's consistent with the common experience that mood and diet seem to have neurochemical ties.


The brain needs glucose, fat and protein in just the right balance, and don’t forget hydration. From what I’ve heard the brain is just this big mass of jelly that is folded like a towel.

All life is sorrowful and the world is an ever burning fire, so enjoy the stately dance of the mystic bliss beyond pain, for that is at the heart of every mythic rite.