The Link Between Diabetes and Depression: What to Know

Arun was depressed. He was underperforming at his job, his relationship was all but over, and he seemed to be losing weight and feeling a lot of fatigue. Arun knew he was depressed - he was undergoing psychiatric treatment. But the weight loss had no answer. It started with a couple of kilos a week and became more rapid, with him dropping more than a few kilos each week. What Arun did not know was that he was also diabetic.

Research indicates that 24.9% of patients with diabetes experience depression. Depression is 2-3 times more prevalent in diabetics than in the general population. 16.8% of youth aged 18-24 in India suffer from depression as of March 2022. How does depression impact diabetes? Or vice versa? Read on and find out.

Female gender :

Women are more susceptible to developing depression than men. This risk might be because of biological differences, race, culture, education, diet, and other socio-economic factors. Depression is more than double as prevalent in young women than men for the ages of 14-25 years. The National Institute of Mental Health says that the prevalence of major depressive episodes was higher among adolescent females (29.2%) compared to males (11.5%)

Women are more sensitive to interpersonal relationships and also experience particular forms of depression-related situations like postmenopausal depression, premenstrual dysphoric disorder, and postpartum depression.

Younger age :

Unipolar depressive disorder in adolescence is quite prevalent worldwide but is not recognised. Unipolar depression, also called major depressive disorder, is a mental health condition that is characterised by a constant low mood and other symptoms. It is different from bipolar depression, which involves phases of depression and mania.

Depression comes with present and future morbidity and increases the risk of suicide. When you are younger, you face more challenges and might feel persistent sadness, irritability, withdrawal from activities and changes in sleep or appetite.

Longer duration of diabetes :

The longer the duration of diabetes, the more likely that person will experience depression symptoms. Over time, individuals might experience deteriorating health, complications and the burden of managing diabetes, which can cause emotional exhaustion. Exposure to the demands of diabetic management, together with the fear of long-term complications, can result in feelings of helplessness and sadness.

Presence of complications :

Diabetes-related complications like neuropathy or retinopathy significantly alter the risk of depression. Such complications can result in chronic pain, discomfort and functional limitations, such that they severely impact an individual’s quality of life.

Ongoing physical symptoms and the stress of managing them can cause hopelessness and frustration. The painful effects of such complications can result in self-esteem issues and social withdrawal, further exacerbating depressive symptoms.

Family history of depression :

Having a family history of depression might influence an individual’s understanding and management of their own mental health. This shared familial environment can expose individuals to similar stressors and coping mechanisms, further exacerbating their risk.

Depression and genetics are closely related - depression can run in families. While no single gene has been definitely linked to depression, several genes that take part in neurotransmitter systems have been linked to increased risk. Understanding the genetic basis of depression can help inform treatment and prevention strategies, though it’s essential to consider the multifaceted nature of the disorder.

Let’s face it, there is no direct relation between diabetes and depression. But there are some definite links between the two if you decide to dive a bit deeper.

Inflammation and oxidative stress :

Inflammation and oxidative stress cause damage to neuronal metabolism and bring down the response rate to antidepressant medications. A low level of dopamine and another neurotransmitter, serotonin, can cause depression. Neurotransmitters dictate mood.

When an increased level of signalling molecules or neurotransmitters and reactive oxygen species (ROS) causes further changes like the reduction of serotonin and dopamine, it tips the domino that snowballs into depression.

Depression, in the same way triggers a set of chemical imbalances from the three main hormone glands (hypothalamus, pituitary, and thyroid). This can offset the secretion of Insulin and Glucagon, which is the primary reason of diabetes, both Type 1 and Type 2.

Neurotransmitter imbalance (serotonin, dopamine) :

Neurotransmitters like serotonin, norepinephrine, and dopamine are present in the brain in certain balances that keep our mental health sane. If your serotonin and dopamine levels fall below average, you are at risk of depression. An imbalance of dopamine can result in depressive symptoms like apathy and hopelessness while having a serotonin imbalance can impact how emotions are processed.

The sudden drop in the ‘Happy hormones’ may trigger your brain to increase its secretion by eating or drinking more food than usual. Atypical depression is known for increasing appetite and sleep requirements.

Hormonal Changes (Cortisol, insulin):

When the hormones are in order, we are fine. However, when they decide to act up, things go wrong. Cortisol is a stress hormone—if its levels increase, it can lead to anxiety and depression. Similarly, insulin resistance can cause mood swings and fatigue.

Genetic predisposition :

There is evidence that suggests that if your family members have struggled with depression, you might be at greater risk of developing this mental health issue. According to research, the heritability rate of depression is around 37%. Also, data from family studies show a two- to threefold increase in the risk of depression in first-degree offspring of patients with depression (The genes that are associated with depression have different functions in the brain).

In most cases of depression, around 50% happens because of genetics, and 50% is unrelated to genes. We also need to understand that there are many cases where both factors overlap.

How do we ascertain whether genes play a role in causing depression? Scientists observe patterns of illnesses in families to find their “heritability”, or roughly what percentage of this issue has been caused by genes. To see this, we locate people with the disease who have a twin and also find whether that twin is ill. Identical or monozygotic twins share 100% of their genes, while non-identical fraternal or dizygotic twins share 50%.

If genes are a portion of the cause, we expect a patient’s identical twin to have a much higher disease risk than a non-identical twin. That is the case for significant depression. Heritability is around 40-50% and could be more for severe depression.

The researchers have been trying to put a finger on what exactly causes genetic depression, however, with little luck. In future, we might break through in the research and that will significantly increase our understanding of the phenomenon.

Patient Health Questionnaire:

This PHQ depression scale has nine items and is half the length of its contemporaries. It consists of the actual nine criteria upon which the diagnosis of DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, fourth edition) depressive disorders is based. These scores can be used to plan and monitor treatment.

Nine Questions of the Patient Health Questionnaire:

1. Little interest or pleasure in doing things.
2. Feeling down, depressed or hopeless.
3. Trouble falling asleep, staying asleep or sleeping too much.
4. Feeling tired or having little energy.
5. Poor appetite or overeating.
6. Feeling bad about yourself - or that you’re a failure or have let yourself or your family down.
7. Trouble concentrating on things, such as reading the newspaper or watching television.
8. Moving or speaking so slowly that other people could have noticed. Or, the opposite - being so fidgety or restless that you have been moving around a lot more than usual.
9. Thoughts that you would be better off dead or hurting yourself in some way.

Beck Depression Inventory :

This 21-item self-report rating inventory created by Dr Aaron T Beck in the 1960s has been designed for grading depression in adults. He was an American psychiatrist and professor in the Department of Psychiatry at the University of Pennsylvania. He is regarded as the father of cognitive therapy and cognitive behavioural therapy (CBT).

The Beck Depression Inventory has been developed in various forms, including computerised forms, a form on a card, and, more recently, the Beck Depression Inventory-II or BDI-II. The BDI, or the original Beck Depression Inventory, is designed to assess the severity of depression in individuals aged 13 and older. It isn’t a diagnostic test, but healthcare workers can use it to make a diagnosis. For BDI-II, scoring from 10-18 means you have a mild form of depression, while 30 or more indicates severe depression. The total range of scoring is from 0-63.

Hamilton Rating Scale for Depression :

The HDRS is a widely prevalent clinician-administered depression assessment scale. It was first formulated for hospital inpatients, which is why it places stress on melancholic and physical depression symptoms. One drawback of this system is that atypical symptoms of depression, like hypersomnia and hyperphagia (extreme unsatisfied drive to consume food), are not assessed.

Impact on Diabetes Management:

Poor glycaemic control:

When people skip or incorrectly take their diabetic medication, it can lead to poor blood sugar, resulting in frequent complications. This can increase frustration, helplessness and hopelessness, contributing to depressive symptoms. The vicious cycle of low health and low mood can bring down motivation to adhere to medication regimes as well as the outlook on life.

Increased risk of complications :

Depression increases the risk of complications in diabetes. People with diabetes and depression struggle with poor care, including less-than-regular self-care, less-than-regular glucose monitoring and inconsistent medication adherence. This can result in inadequate glycaemic control and a prevalence of complications like neuropathy, retinopathy and cardiovascular issues.

Decreased quality of life :

Depression can significantly reduce the quality of life for people with diabetes. The emotional burden of depression, together with the daily task of managing diabetes, can result in diminished overall well-being. You might experience reduced energy levels, lack of motivation and impaired cognitive function, making it more challenging to stick to diabetes management routines.

All this lowers the quality of life, affecting physical and mental health. Read more about how a poor lifestyle can give rise to health issues and how you can beat these lifestyle diseases with just lifestyle changes and not medication.

Selective Serotonin Reuptake Inhibitors (SSRI):

According to research, SSRIs are the most commonly prescribed antidepressants. Citalopram is a Selective Serotonin Reuptake Inhibitor that increases serotonin levels in the brain. It has been linked with better glucose metabolism and weight loss, which can reduce the risk of poor glycemic control.

Citalopram regulates blood glucose and insulin resistance by controlling the hypothalamic-pituitary-adrenal (HPA) axis. It also has direct antioxidant and anti-inflammatory effects that can improve blood glucose.

Serotonin-norepinephrine reuptake inhibitors (SNRIs):

These medicines work by keeping specific chemical messages active in your brain. They have traditionally been a group of interrelated antidepressants based on reuptake inhibition. They display varied chemical structures and different pharmacological properties.

Both neurotransmitters are essential for regulating mood, sleep-wake cycle, and memory. More serotonin and norepinephrine are active in the brain, keeping your mood up.

Psychotherapy (cognitive-behavioural therapy, interpersonal therapy):

Diabetes distress usually causes depressive symptoms, with common comorbidity of diabetes affecting the patient’s medical and psychological functions. Cognitive Behavioural Therapy is incredibly tremendous in treating depressive symptoms, as is interpersonal therapy. CBT is 50-75% effective as compared to other therapies when it comes to depression.

CBT deals with current problems, not issues from the past. Interpersonal therapy helps you communicate better with others and address concerns that contribute towards depression.

Lifestyle modifications

Lifestyle changes can improve outcomes for individuals battling diabetes and depression. A balanced diet loaded with whole grains, fruits, vegetables, and proteins supports stable blood glucose levels.

Techniques like mindfulness, meditation, and yoga can reduce depression symptoms and improve diabetes management. Establishing a proper sleep routine and engaging in social activities can also improve mental and physical health.

Limited mental health resources -

In India, mental health resources are limited. There are just 9000 psychiatrists and counting. In addition, around 700 psychiatrists graduate each year. Hence, India has around 0.75 psychiatrists per 10000 people.

In terms of research, not much has been done on mental illnesses and the impact they have on our lives. Treatment facilities, too, are nascent. In such a situation, if you have depression, it is challenging to get proper treatment with the appropriate facilities and adequate care.

The stigma surrounding mental illness -

Do one thing. Go around telling your family and friends that you are suffering from depression. You are sure to receive judgemental looks and unsolicited advice about depression. Mental health issues are viewed through a lens of shame and weakness (read masculinity), resulting in discrimination, silence and marginalisation of those affected.

Many individuals are scared to seek treatment because of fear of judgement or social ostracization. According to India’s National Mental Health Survey, there is a treatment gap of around 85% for mental disorders, attributed to a lack of awareness and access to primary psychiatric care in India.

Lack of awareness among patients and healthcare providers -

Most individuals with depression will remain untreated because healthcare providers have limited training in mental health, creating a knowledge gap that leads to underdiagnosis and under-treatment, worsening the burden of depression.

Inadequate insurance coverage for mental health services

In India, insurance companies do not cover mental health services. If you have an insurance agent, please ask them whether they cover mental health. Chances are that your agent might not have even heard about mental health and what it entails. Mental health treatments are excluded from insurance plans, placing a significant financial burden on individuals seeking care.

Conclusion

In conclusion, don’t be like Arun. If you are diabetic, get checked for depression. If you are depressed, get a check for diabetes, regardless. And if you are depressed and suffering from diabetes, get a diagnosis of anxiety as well. Diabetes and depression are intricately linked to a great extent. Recognising it early and proceeding with diagnosis and treatment for depression is essential for effective diabetes management.

The unique challenge is to integrate mental health services into diabetes care. Once that is achieved, care for patients suffering from both conditions might become comprehensive and more empathetic.

If I am depressed, what do I do?

If you feel that you are depressed and are showing signs of depression, please speak to a psychiatrist to get a proper evaluation of your mental health.

If I am diabetic, what is the future course of action?

If you are diabetic or suspect that you have diabetes, please speak to your healthcare provider and come up with a feasible solution and course of treatment.

If I am diabetic, do I also have depression?

Depression and diabetes can co-exist. If you are diabetic, please get a screening for depression. A doctor will be able to give you an accurate picture.

How do I get healthy?

You can get healthy by regular exercise, maintaining a proper diet and getting enough sleep. If you are a healthy adult, around eight hours of sleep a day should do.