Depression and Dementia- Unravelling the intricate connections

Published: Oct 07, 2020

Depression and dementia are two common disorders of the nervous system that have a serious impact on our quality of life. While depression is a treatable condition, dementia remains incurable, for the most part. The connection between the two conditions has been baffling and has been explored for several years. We now know that there exists a complex and intricate connection between both disorders.

A common mood disorder, the lifetime prevalence of depression is estimated to be around 16%. The current stats indicate that 5% of community-dwelling older adults, and up to 15% of long-term care residents have depression. In reality, it could be much higher than that. As with dementia, the estimated low prevalence could be partly attributed to stigma towards the disease.

Age of onset
The average age of those diagnosed with depression is 32 years. However, there is a second group that is at risk of developing depression and that is older adults. The major losses, such as death of spouse, declining health due to chronic health conditions, etc. and significant life events, including retirement, moving into assisted living, and so on, experienced by older adults make them susceptible to develop reactive depression.

Sex/gender difference
Women have almost double (1.7 times) higher risk of developing depression during their lifetime compared to men. This is the case with dementia as well. This is suspected to be due to differences in life events, and hormonal and developmental differences in brain circuitry. Pre-menstrual worsening of depressive symptoms and post-partum depression after childbirth are common, and reflect this increased risk.

Depression and dementia connection
People with depression often experience cognitive impairment. Therefore, depression is regarded as cause of treatable dementia. Moreover, about 20% of those whose depressive symptoms increase over time have been found to develop dementia. At the same time, 40% of persons living with dementia have severe depressive symptoms. Depression may co-exist in mild and moderate dementia due to any cause. Depression is usually associated with mild-moderate Alzheimer’s disease, vascular dementia, dementia with Lewy Body, and Parkinson’s disease dementia.

Depression can be associated with health conditions such as heart disease, diabetes, arthritis, Parkinson’s disease, stroke, thyroid hormone deficiency, MS, inflammatory bowel disease (IBD), traumatic brain injury, and cancers. Several medications have been found to be associated with depressive symptoms. These include some blood pressure medications (Reserpine, Beta-blockers etc.); some anti-epileptics; some antiviral drugs (HIV drugs, for instance); Opioids; and some steroids. Not everyone on these medications would develop depressive symptoms. Additionally, late-onset depression (depression occurring for the first time in late life) has been recognized as an early prodromal symptom of an impending dementia.

The common symptoms of depression are low energy level, changes in appetite, poor sleep (although the person may appear to be sleeping all the time), social withdrawal, loss of interest and enthusiasm for previously enjoyed activities, low mood, sad thoughts, and suicidal ideation. Older adults may have slightly different symptoms- they may not openly express sad thoughts, and suicidal ideation, and are less likely to attempt suicide. Instead, they may have physical symptoms such as prolonged, vague aches and pains.

Recognizing depression in persons living with dementia
In persons living with dementia who also develop depression, caregivers would notice worsening of cognitive symptoms, decrease in functional abilities, increasing apathy (loss of initiative or drive to do things), decreased participation in activities, decreased ability to experience joy, increased mood changes, sleep pattern changes, and increased dependence on caregivers. Caregivers suspecting depression in the person living with dementia should discuss with the physician. There is great value in treating depression in early dementia, and you would see a definite improvement in dementia symptoms, better mood, increased participation in activities, better sleep, and a higher energy level. Treating depression improves the quality of life of the person living with dementia and their caregiver. Caregivers could request a referral to a Geriatric Psychiatrist, if the initial drug therapy fails. 

Many caregivers have depressive symptoms, and ignore them, unfortunately. If you are a caregiver and you are experiencing some of these symptoms, please consult your doctor promptly and take appropriate medications. Low energy levels, mood changes, and sleep disturbances associated with depression would certainly impact your ability to provide care, and lead to behaviour changes in your person. It can ultimately affect your heart health and brain health. Hence, the importance of seeking timely medical help.

Management of depression
Depression is a treatable condition. Medications such as Selective Serotonin Reuptake Inhibitors (SSRI), and Serotonin Norepinephrine Reuptake Inhibitors (SNRI) are the commonly used first line of medications. Several other groups of medications, psychotherapy (cognitive behavioural therapy, problem-solving therapy, mindfulness-based therapies etc.) and nonmedical strategies are available for controlling depression. About 2/3rds of persons with depression will respond to either medication or psychotherapyabout 50%or greater reduction in symptoms, but only 30% to 40% will have a full remission of symptoms with the first treatment intervention. For psychotherapy to be effective, the person must have intact cognition to be fully engaged and have the ability for introspection. Some persons will respond only to one and not to the other. There are no ways to predict which treatment option will help an individual patient. Somatic treatments such as Bright light therapy, magnetic /direct current stimulation, and other forms of neurostimulation, such as electroconvulsive therapy, are often considered when psychotherapy and multiple trials of medications are ineffective. Be aware of symptoms and signs of depression. Persons living with dementia whose caregivers have depression, have a poor quality of care, poor quality of life, and have a shorter life span compared to others. Recognizing the signs of depression and getting it treated in a timely manner will benefit you and your person living with dementia.

Padma Genesh, Learning Specialist