Psychiatrists are often asked ifpeople become more depressed as they grow old. If yes, is depression more difficult to treat in old age? Late-life depression (LLD) is caused by multiple factors working together. It has three broad risk factors: biological, psychological, and social.
What are the biological risk factors?
Scientists are yet to identify a candidate biomarker – a biological molecule in blood, body fluids, or other tissues, that is a sign of a disease process – for LLD. On the other hand, studies have found some evidence for genetic contribution to LLD. Scientists have also advanced several hypotheses involving the genes that code for serotonin synthesis, norepinephrine transporter, and the neurotrophic factor, but these ideas require more tests. A subset of LLD, called vascular depression, may be associated with cerebrovascular lesions.
Stress that accumulates over one’s life leads to a sustained secretion of cortisol, the hormone that regulates the body’s stress response. Increased cortisol levels lead to the loss of brain cells in the hippocampus, which is implicated in memory and learning. (This brain cell loss can be partially mitigated by the use of antidepressants.)
Researchers have proposed a vascular theory based on the observation that depression is a frequent outcome in people who have had a stroke. Vascular depression is associated with brain lesions, which appear as bright spots on brain scans. These spots, called white matter hyperintensities, disrupt brain signalling and brain circuits.
Heart attacks and heart conditions often lead to LLD, as do diabetes and hip fracture. Depressive symptoms can also manifest if a person doesn’t optimally recover from physical illnesses.
What are the psychological risk factors?
Personality attributes may colour the origin and expression of depressive symptoms in older adults. Neuroticism – the personality disposition to experience negative emotions, anger, irritability, and emotional instability – is consistently implicated in LLD.
Depressed individuals may overreact to life events or misinterpret them. Recent adverse life events (loss of a job, bereavement, etc.) are more frequently reported among depressed elderly people than among non-depressed older adults.
Locus of control refers to the degree to which an individual feels a sense of agency in their life. A person with an external locus of control will feel that external forces – such as random chance, environmental factors, or the actions of others – are more responsible for the events that occur in the their own life. The 1995 Longitudinal Aging Study Amsterdam found that the emergence and persistence of depressive symptoms was predicted by having an external locus of control.
What are the social risk factors?
Lower socioeconomic status has been associated with depression across the life cycle. The construct of social support includes perception, structure of the social network, and the tangible help and assistance available. Perceived social support is the most robust predictor of LLD symptoms.
In my practice, I hear people saying that while their old social networks have thinned out, many new ones have emerged – a timely reminder to not assume that older adults are bound to experience deficits in social support.
How is clinical assessment of depression conducted?
Clinical assessment involves:
- Evaluating the duration of the current episode,
- Screening for previous depressive episodes,
- Ruling out substance misuse,
- Looking at the course of previous episodes, if any,
- Ascertaining the response to previous interventions, and
- Looking at a family history of depression and/or suicide
Assessing the cognitive status of the individual is critical to evaluate depressed older patients. This is aided by the use of screening scales such as the Mini Mental-State Examination. No assessment is complete without a thorough physical examination of all the other systems as well.
Frequently, physicians order tests involving the thyroid and metabolic panel, vitamin B12, folate and vitamin D levels, and some other biochemistries. Physicians also often order a brain scan for LLD. This is to rule out other possible pathologies (such as stroke or tumour), which may present with a clinical picture of depression.
The physician may also order an electrocardiogram before medication.
How is late-life depression treated?
Experts generally take a four-pronged approach to treat geriatric depression, involving psychotherapy, medications, brain stimulation, and family therapy.
Talking therapies, such as cognitive behaviour therapy (CBT), help to identify maladaptive thought patterns, and then restructure these patterns to help the depressed individual cope and feel better.
Maladaptive cognitions, such as “I am useless” or “It’s all going to go wrong”, are subject to empirical examination. The therapist will seek evidence in support of these ideas and alternative ways to view one’s own life.
The individual may also be asked to keep a diary of activities, to set goals, and to try doing things that they fear. This is often accompanied by encouraging the individual to write down their goals and to track their progress.
Typically, there will be six to 20 CBT sessions, with each session lasting for 30-60 minutes. There is some evidence to suggest that the long-term benefits of CBT could equal that of drug therapy.
A range of safe and effective drugs are available to treat geriatric depression When combined with talk therapy, the efficacy of either of the interventions increases. A common dictum in prescribing medications to older adults is to ‘start low and go slow’. Antidepressants are often asked to be taken for six to nine months after the remission of a depressive episode. Contrary to popular belief, these drugs are not addictive, and patients can be safely weaned off them once the course is complete.
Neurostimulation modalities such as electroconvulsive therapy (ECT) are used to treat severe forms of depression, suicidality, and psychotic depression (characterised by delusions and hallucinations). ECT continues to be the most effective treatment for people with severe major depressive episodes.
Can family members help?
The final component of therapy for LLD is working with the family. A dysfunctional family may contribute to depressive symptoms. Family support is critical for a successful outcome in the treatment of the elderly individual. Families are taught to acknowledge the individual’s distress with helpful responses such as “I hear what you are saying, and I understand”.
Family members are educated about the nature of the depressive disorder, and the potential risks of geriatric depression, especially suicide. They can assist the clinician by observing behavioural changes in the individual, including increased withdrawal, decreased verbal responses, and a preoccupation with medications or weapons.
The family can also help by removing possible implements of suicide from places of easy access. The family can also assume the responsibility of administering medications to an older adult who may be non-adherent or whose risk of self-harm is high.
LLD is verily treatable. The onus lies on us to take care of our elderly.
Dr. Alok Kulkarni is a senior geriatric psychiatrist and neurophysician at the Manas Institute of Mental Health and Neurosciences, Hubli.
Published - March 20, 2023 10:30 am IST
