TREATING INSULIN RESISTANCE MAY IMPROVE DEPRESSION

In a new small experimental trial, researchers found that the diabetes drug pioglitazone (Actos), which makes the body more sensitive to insulin, helped relieve symptoms of chronic depression in people with insulin resistance.  These results add to growing evidence of a connection between insulin resistance — the body’s inability to efficiently process glucose, even with adequate insulin production in the pancreas — and mood disorders.  Insulin’s important role in brain function is well-documented.  Brain cells, unlike many other cells, can only use glucose for fuel and the brain accounts for one-fifth of all glucose use in an active human being.   So, it makes sense that impaired glucose uptake due to insulin resistance would affect many pivotal processes in the brain.

Insulin resistance is often a precursor to type 2 diabetes.  Normally, when food is consumed, blood sugar levels in the body increase, and, in response, insulin is released by the pancreas, signaling the cells to take up the glucose and use it for food.  However, the cells of people with insulin resistance fail to take up glucose adequately, causing blood sugar to stay elevated longer than normal.  This increases inflammation in the body and, if unchecked, leads to type 2 diabetes. 

The 12-week study involved both insulin sensitive and insulin resistant patients whose symptoms of depression had failed to improve substantially, despite treatment.  Half the participants were randomly selected to receive treatment with pioglitazone while the other half received a placebo.  Throughout the study, patients’ levels of depression and insulin resistance were monitored. Researchers found the insulin resistant patients on pioglitazone showed significantly improved depressive symptoms while those on the placebo did not.  Also, the more insulin resistant a participant was at the beginning of the study, the better the drug’s antidepressant effect.

What to do:  Excess weight and inactivity are potent risk factors for insulin resistance.  Even though your fasting glucose may be normal you may still have insulin resistance.  Discuss being screened for insulin resistance with your healthcare provider.  Checking hemoglobin A1C in bloodwork is one way to screen for the presence of insulin resistance.  Whether drugs for insulin resistance are a safe, effective way to treat depression in insulin resistant individuals remains to be seen but, in the meantime, weight loss and regular cardiovascular activity are two sure fire means of reducing insulin resistance.  And, there is also plenty of evidence that healthier weight and activity are both supportive of mood.   

Source:

Lin KW, Wroolie TE, Robakis T, & Rasgon NL.  Adjuvant pioglitazone for unremitted depression: Clinical correlates of treatment response.  Psychiatry Research. Published online ahead of print October 12, 2015. DOI: http://dx.doi.org/10.1016/j.psychres.2015.10.013

Adapted from articles available at:

http://med.stanford.edu/news/all-news/2015/11/insulin-sensitizing-drug-relieves-symptoms-of-chronic-depression.html

http://www.medscape.com/viewarticle/854618

https://www.nlm.nih.gov/medlineplus/news/fullstory_155792.html