Multimorbidity and Dementia: The Risks Along With Future Care Needs

Thanks to advancements in medical care, the adoption of new technologies, and overall improved living conditions, global life expectancy has seen a steady increase over the past two centuries. Unfortunately, as aging is the primary risk factor for many diseases and conditions, a longer life means there is a higher probability of developing multiple long-term health conditions, such as dementia, diabetes, cardiovascular disease, and sensory impairments. 

Comorbidity and multimorbidity are typical of the majority of individuals living with Alzheimer’s and other causes of dementia. However, healthcare systems are more or less designed around single-organ diseases, not multimorbidity, which can greatly impact the quality and efficacy of patient treatment and care. Additionally, numerous studies have demonstrated that multimorbidity significantly increases the risk of dementia development.

Below, we take a closer look at multimorbidity and dementia, including research surrounding multimorbidity and dementia risk, how multimorbidity affects the needs of dementia patients, and the need for more precise, personalized treatment and care.

What Is Meant By Multimorbidity?

Multimorbidity is conventionally defined as the presence of two or more long-term health conditions or chronic diseases, regardless of the severity of such conditions. The working definition of multimorbidity has been expanded by the National Institute for Health and Care Excellence to include the following criteria for long-term health conditions:

• Defined physical and mental health conditions (e.g. diabetes and schizophrenia)
• Ongoing conditions (e.g. learning disabilities)
• Symptom complexes (e.g. fragility and chronic pain)
• Sensory impairments (e.g. hearing impairments and vision impairments)
• Alcohol and substance misuse

Multimorbidity and Dementia Risk

It is well-known that individual diseases and health conditions, such as cardiovascular disease, stroke, and hearing loss, can increase the risk of developing dementia later in life. However, newer research aims to assess the impact of multimorbidity on dementia risk.

A 2021 study assessing the impact of multimorbidity and dementia risk found that individuals with neuropsychiatric, cardiovascular, and sensory impairment/cancer patterns are at an increased risk for developing dementia. They also found that APOE4 and inflammation may further increase the risk of dementia.

In 2022, a 30-year follow-up prospective cohort study aimed to investigate the association between age at onset of multimorbidity and incidence of dementia. The study found that multimorbidity, especially when onset occurs in midlife rather than late life, had a strong association with subsequent dementia.

This research emphasizes the importance of taking a preventive approach to medicine and identifying patients at high risk of developing dementia as early as possible to enable tailored interventions for effective dementia prevention measures.

Multimorbidity and Dementia: The Need for Precision Medicine Approaches

As mentioned above, multimorbidity is quite common in individuals living with Alzheimer’s and other causes of dementia. Research suggests that multimorbidity is associated with a poorer quality of life as well as increased risks of polypharmacy, adverse drug reactions, falls, and hospital admissions. 

This suggests that there is an urgent need for providers to take multimorbidity into account at a personalized level when tailoring an approach to care and treatment, rather than focusing on each disease or condition separately, particularly when mental and physical conditions overlap. Taking all conditions into account and creating an individualized management plan can not only improve health outcomes but can improve the quality of life by reducing adverse events and uncoordinated or disjointed care.

Additionally, several studies have found that multimorbidity contributes to the clinical progression of dementia; more specifically, multimorbidity is associated with accelerated decline in individuals with dementia, but not in individuals without dementia. This demonstrates the importance of frequently and consistently assessing neurocognitive function to adequately update care and treatment plans to meet the changing care needs of patients.