Diabetes and Depression

 Examining a Bidirectional Association Between Depressive Symptoms and Diabetes by Dr. Sherita Hill Golden (JAMA).

One complication of diabetes that does not receive much attention is depression. Compared to the general population, people with diabetes tend to have significantly more clinical depression and depressive symptoms. Despite much research, the question still remains: does diabetes cause depression or does depression cause diabetes? In this issue’s What We’re Reading, diaTribe looks at the most recent study by Dr. Sherita Hill Golden, which attempts to answer this question.

the study design

In this study, participants had three examinations over an average of 3.1 years, one between 2000-2002, one between 2002-2004, and the last between 2004-2005. The study participants were categorized as having either normal fasting glucose (under 100 mg/dL or 5.6 mmol/L), impaired fasting glucose (100-125 mg/dL or 5.5-7.0 mmol/L), or type 2 diabetes (greater than or equal to 126 mg/dL [over 7.0 mmol/L] or receiving treatment). Depressive symptoms were also assessed during the first and third visit using a 20-question depression scale (CES-D). This test asked participants to rate items on a scale from 0 to 3 to assess depressive behavior and feelings over the past week. The scores (known as CES-D scores) range from 0 to 60, with a score above 16 indicating a clinically significant level of depressive symptoms.

does diabetes cause depression?

To get to this question, the authors looked at individuals that did not have depressive symptoms at the first visit. This group was split into those with and without type 2 diabetes. At the third visit, about 3 years later, they found that:

• 12.1% of those individuals with diabetes had CES-D scores above 16 compared to 10.6% of individuals without diabetes.

• People being treated for type 2 diabetes had a 52% higher chance of developing depression than individuals with normal fasting glucose.

• Individuals with untreated type 2 diabetes did not have an increased risk of depression compared to people with normal fasting glucose.

does depression cause diabetes?

For this question, the authors selected a group of 5,201 participants that did not have type 2 diabetes at the first visit. These individuals were then split into two groups: those that had a CES-D score of above 16 or those with scores below 16. After three years, the authors compared the rates of diabetes between these two groups and found the following:

• Among individuals without elevated depressive symptoms, 5% developed type 2 diabetes.

• Among individuals with elevated depressive symptoms, 6.5% developed type 2 diabetes.

• With each five-point increase in CES-D score, the relative risk of developing type 2 diabetes increased 1.1 times.

• Thus, people with a high CES-D score should know that it may increase their risk for developing type 2 diabetes. One hypothesis for this connection is that people who are depressed tend to eat more and exercise less. This unhealthy lifestyle is an independent risk factor for type 2 diabetes. Another explanation suggested is that the stress of depression may lead to hyperglycemia.

conclusion

The findings of this study are quite sobering, particularly the idea that the hard work we do in treating diabetes may actually lead to depression. diaTribe advisory board member and resident psychology expert and diabetes educator, Dr. William Polonsky (Behavioral Diabetes Institute) sums it up best:

1. The evidence suggesting a bidirectional relationship between depression and diabetes is certainly troubling

2. Dr. Fisher (UCSF), amongst others, suggests that certain depression tests, like the CES-D, may not accurately measure depression as well as we might think; in fact, high scores on these tests may be more accurate reflections of "diabetes burnout." These two concepts are related but not at all equivalent and thus require different treatments

3. The good news is that both conditions are treatable and diaTribe readers should take the initiative to discuss with their educators or physicians if you notice any of the symptoms

special note for our readers:

Similar to diabetes, it is not often easy to spot depressive symptoms. The association between diabetes and depression should be taken into account by clinicians, and they should routinely screen their treated type 2 patients for depressive symptoms. According to the American Diabetes Association, some symptoms that everyone with diabetes should be aware of include:

• No longer taking pleasure in things you used to enjoy.

• Changes in sleep pattern or feeling tired all the time.

• Eating more or less than normal.

• Having trouble concentrating.

• Constantly feeling anxious and/or guilty.

• Thinking about hurting yourself or suicide.

If you would like to take the CES-D test, it is available for free at: http://counsellingresource.com/quizzes/cesd/index.html

There are some great communities of people with diabetes out there, so you should never have to deal with your diabetes alone. If you think that you are seriously depressed, please seek medical attention.