In the 21st century, a perfect storm is brewing, largely unnoticed by many: the convergence of two high-prevalence, high-impact brain conditions—mental illness and dementia. These conditions, once studied in isolation, are now being recognized for their interconnectedness, revealing a complex relationship that demands our attention.
Recent medical research has uncovered compelling evidence that links mental health disorders with cognitive decline. While the exact nature of this relationship remains uncertain—whether mental illness contributes to dementia or vice versa—the reality is stark: we are losing our cognitive faculties at an unprecedented rate, and this trend is not confined to Australia alone.
Neuroscience has taught us that the health of our brains is paramount in determining our life trajectory, especially as we age. In Australia, one in five individuals will experience a mental health disorder at some point in their lives, with conditions ranging from anxiety and depression to more severe psychotic illnesses like schizophrenia and bipolar disorder. The Australian Institute of Health and Welfare reports that for every 1,000 Australians, one in 15 suffers from cognitive impairment, with Alzheimer’s disease and vascular dementia being the most common causes.
On a global scale, the statistics are staggering. The World Health Organization (WHO) estimates that over 970 million people worldwide live with a mental health disorder, while 55 million individuals are affected by dementia. Alarmingly, 60% of those with dementia reside in middle- to low-income countries. The Western Pacific region, which includes Australia, is home to the largest and fastest-growing aging population, projected to account for more than 50% of global dementia cases by 2050.
This growing understanding of the links between mental health and dementia presents a unique opportunity. By addressing these issues in tandem, we can explore innovative approaches to prevention, risk reduction, early diagnosis, treatment, and care. The potential benefits extend far beyond Australia and the Western Pacific, impacting global health outcomes.
Families often share conditions that affect both the brain and the mind. For instance, individuals diagnosed with dementia frequently have family histories of mental health disorders such as bipolar disease, schizophrenia, and autism. This correlation suggests that psychiatric treatments, like lithium, could be beneficial for dementia patients. Conversely, therapies designed for dementia, such as monoclonal antibodies targeting brain inflammation, may also hold promise for treating psychosis.
On September 17, Neuroscience Research Australia (NeuRA) and The Lancet Regional Health – Western Pacific launched a Dementia Series, providing global reviews of the best scientific and clinical evidence to create a roadmap for the region. This initiative highlights the importance of identifying modifiable risk factors for dementia, which now include depression and hearing loss, alongside previously recognized risks such as hypertension, obesity, tobacco use, alcohol consumption, and physical inactivity. The Lancet Commission now estimates that 45% of dementia cases could be delayed or reduced through targeted interventions.
The economic implications of mental illness and dementia are staggering. The Productivity Commission has calculated that mental illness costs Australia up to AU$70 billion annually in direct expenditures and lost productivity. Meanwhile, Dementia Australia estimates the economic burden of dementia at AU$15 billion each year. Addressing both health issues simultaneously could potentially alleviate an annual economic burden of AU$85 billion, not to mention the profound personal impacts on individuals and their caregivers.
As one of the few high-income countries in the Western Pacific, Australia is uniquely positioned to take a leadership role in combating the rising tide of cognitive decline. The National Dementia Plan serves as a guiding framework for similar initiatives across the region, emphasizing culturally appropriate strategies that engage local communities. A key focus is on prevention and education, particularly in addressing modifiable risk factors associated with both depression and dementia.
To achieve meaningful progress, we must enhance diagnostic capabilities and integrate care models for depression and dementia, tailored to the diverse cultural and ethnic groups within the region. Additionally, expanding support services for caregivers is crucial. Currently, dementia research accounts for less than 3% of total global health research output, highlighting a significant gap that must be addressed.
One of the most concerning findings from the upcoming series in The Lancet Regional Health – Western Pacific is the acceptance of brain impairment as a normal part of aging in many low- to middle-income countries. Families often shoulder the burden of care, inadvertently relieving governments and healthcare systems of their responsibilities to address these pressing issues.
In a modern reinterpretation of the African proverb, “It takes a village to raise a child,” we must recognize that collaborative, multi-sectoral efforts are essential for reducing cognitive impairments associated with dementia and mental illness. This requires investment at both national and international levels, fostering partnerships that prioritize the voices of those with lived experiences and their caregivers.
What Can You Do?
For professionals in health, mental health, and aged care, there are immediate actions we can take to combat the rising prevalence of mental illness and dementia. We can deepen our understanding of these conditions and their interconnections, actively listen to our patients and communities, and empower individuals to recognize modifiable risk factors.
Encouraging regular health checks, such as hearing tests and blood pressure monitoring, can help address diabetes, alcohol misuse, smoking, obesity, physical inactivity, depression, and social isolation. Research indicates that a 20% reduction in these risk factors could lead to a 15% decrease in Alzheimer’s disease cases by 2050.
New treatments for dementia are on the horizon, with monoclonal antibody therapies targeting amyloid currently under review by the Australian Therapeutic Goods Administration. As research continues to evolve, it is vital to adopt a holistic, multidisciplinary approach to care, integrating the expertise of clinicians, nurses, psychologists, and allied health professionals to support individuals with mental illness and dementia.