Diabetes and Depression: What's the Link?

Diabetes is a chronic ailment which has now become a lifestyle concern.  For long, a person's genetic constitution and obesity have remained as the major causes of diabetes. Genetics is responsible for lending a person the disposition (constitution) that puts them at higher risk of developing diabetes. Diabetes management requires a round-the-clock commitment. People have to make certain dietary changes and also exercise regularly.  A new study published, Journal Proceedings of the National Academy of Sciences (PNAS), reveals that diabetics are more prone to anxiety and depression than those with other chronic diseases that require similar levels of management.   These findings show that insulin resistance that can lead to Type 2 diabetes is linked to behavioural disorder.  "This is one of the first studies which directly shows that insulin resistance in the brain actually can produce a behavioural change," said senior author C. Ronald Kahn, professor at the Harvard Medical School. Researchers explained that insulin resistance may lead to lower levels of the key neurotransmitter dopamine in areas of the brain associated with anxiety and depression. For the study, researchers genetically modified mice to make their brains resistant to insulin. They first found that the animals exhibited behaviours which suggest anxiety and depression, and then pinpointed a mechanism that lowers levels of the key neurotransmitter dopamine in areas of the brain associated with those conditions. The researchers assessed the genetically modified mice in multiple tests that place mice under stress. Young mice behaved much like normal mice, but mice tested at 17 months of age (which is starting late middle-age for mice) displayed significant behavioural disorders. It is not clear as to why these changes in behaviour increased with age, but the effect is common among mouse models of neurological disorders, and has also been seen in the same human neurological diseases.
  With inputs from IANS