Introduction 

Mixed dementia is a complex condition characterised by the coexistence of more than one type of dementia, such as Alzheimer's disease (AD), vascular dementia (VaD), and Lewy body dementia (LBD), presenting unique challenges towards patients and caregivers. 

While mood changes and emotional well-being have been a significant determining aspect of mixed dementia progression, including a spectrum of symptoms, ranging from apathy, and irritability, to depression and anxiety, this could profoundly influence the quality of life among the mixed dementia population. Understanding the interconnectedness of its cognitive decline and emotional disturbances is essential for comprehensive care provision for those with mixed dementia. 

This article will dive into the sophisticated relationship between mixed dementia and mood changes, exploring its manifestations, mechanisms, assessments and management strategies, so as to raise awareness to facilitate better care and support towards these emotional challenges within mixed dementia.¹ 

Common types of mixed dementia 

Alzheimer’s disease with vascular dementia

Alzheimer’s disease (AD) with vascular dementia (VaD) is the most commonly seen mixed dementia subtype. While AD is characterised by amyloid plaque accumulation and tau proteins tangled among neurons, VaD is a result of stroke or small vessel disease that damages blood vessels and impairs blood flow to the brain.² 

Alzheimer’s disease with Lewy body dementia

AD with Lewy body dementia (LBD) has been a less common subtype. While it involves faulty protein clumping among neurons in the brain, it could result in a mix of cognitive, motor, and psychiatric symptoms when coexisting with AD pathology.² 

Vascular dementia with Lewy body dementia

While VaD stems from reduced vessel blood flow towards the brain, LBD is caused by abnormal protein deposits among neurons. As VaD combines with LBD, a wide spectrum of symptoms including cognitive executive function decline, motor dysfunctions, hallucinations, even difficulty sleeping, and fluctuations in alertness exists. 

Mixed pathologies 

In certain cases, an individual may have a combination of brain changes of all three conditions: AD, VaD, and LBD. This mixed pathology can result in a wide range of symptoms that is challenging for clinical diagnosis and management.¹  

Mood changes in different mixed dementia 

Alzheimer’s disease and vascular dementia

Individuals with AD mixed VaD could face a higher risk of emotional disturbances. While depression, anxiety, agitation, aggression, and sundowning effect are some common changes among AD as memory loss (amnesia) and cognitive decline progress, the aggressiveness, mood swing, and apathy towards previous hobbies or the surroundings could be amplified by intertwining with VaD that impairs blood flow towards the brain. This combination often shows up as heightened worriedness, confusion, and irritability. Furthermore, caregivers may also observe social withdrawal, rummaging behaviours, increased paranoia, hallucinations, delusions, and overall emotional distress among their loved ones.^3,4 

Alzheimer’s disease and body dementia

Individuals with a mixture of AD and LBD could experience a unique array of mood changes. The gradual cognitive and executive functional decline of AD could lead to fear, agitation, and apathy, hence pronounced emotional distress when merged with LBD-induced recurrent visual hallucinations, emotional lability, sleep disturbances, motor (i.e. parkinsonism), sensory, automatic dysfunctions, plus cognitive and alertness fluctuations due to faulty protein plaques and tangles among brain’s neurons. This combination can further intensify depression, anxiety, and emotional vulnerability, which could be complex and challenging for caregivers to navigate through.^3,5,6  

Vascular dementia and body dementia

The VaD and LBD compound often present an arduous emotional outlook. VaD-caused cognitive impairments originating from disrupted blood flow to the brain are fused with LBD’s wide range of symptoms such as visual hallucinations, parkinsonism, delirium-like cognitive and ‘switching-off ’-like alertness variations. This complex VaD and LBD mixture often leads to heightened emotional vulnerability, resulting in anxiety,depression-prone significant mood swings and temptation outbursts. Individuals enduring such dual diagnosis may also encounter difficulties such as paranoia, agitation, and emotional lability, further complicating one’s emotional well-being, hence the role of caregivers.^5,6,7   

Threefold combination

The threefold AD, VaD, and LBD mixed pathologies have been a particularly challenging clinical scenario to distinguish due to the complex interplay amongst cognitive, emotional and behavioural declines with their overlapping manifestations. Individuals confronting this rare, triple diagnosis may exhibit a wide variety of symptoms, including anxiety, depression, agitation, aggression, apathy, emotional instability, lability, hallucinations, delirium, plus cognitive and alertness fluctuations. Both healthcare professionals and caregivers have to undergo this laborious task to unwind the hard-to-distinguish shared clinical features, to provide an accurate diagnosis and tailored care for an effective emotional challenges management upon the complex threefold mixed dementia subtype.    

Contributing factors of mood changes among mixed dementia 

Neurological changes 

Neurological changes including neurotransmitter levels (e.g., serotonin and dopamine) alterations, frontal lobe damage affecting emotional regulation, amygdala dysfunction impacting emotional processing, hippocampal atrophy influencing mood stability, plus white matter lesions in disrupting mood-regulatory pathways, could collectively contribute to the observed mood changes among mixed dementia.^8,9,10  

Cognitive and functional decline

Cognitive decline includes progressive memory loss and impaired reasoning which can lead to frustration, confusion, and emotional distress among mixed dementia. Its functional decline, like increased dependence upon difficulties with mobility and daily tasks, could also cause feelings of powerlessness and helplessness, exacerbating mood changes and instability.   

Psychosocial factors

Psychosocial factors such as impaired emotional responses, changes in personality, habit, comprehension of reality, social isolation, lack of meaningful activities, loss of autonomy, and the subsequent burden to caregivers can pose a huge impact on the emotional instability among individuals with mixed dementia.^11,12 

Medication side effects

Medications approved for dementia management, such as cholinesterase inhibitors (e.g., donepezil) and NMDA receptor antagonists (e.g., memantine) can cause headaches, trouble sleeping, skin irritation, and gastrointestinal issues, all of which can intensify emotional instability.¹³ 

Assessment 

Mood changes among mixed dementia are assessed through a comprehensive approach with the following flow:

Clinical interviews

A thorough clinical interview conducted by mental healthcare professionals, such as psychologists and psychiatrists, with the individual and caregivers is essential to gather information about changes in mood, behaviours, and daily functioning. 

Observations 

Behavioural observations (ideally with caregivers) under different settings to note agitation, aggressiveness, mood swings, or signs of emotional distress.  

Standard assessments 

Validate tools (as follows) are used to quantify emotional challenges and trace changes over time. 

• Neuropsychiatric Inventory (NPI)
• Geriatric Depression Scale (GDS)
• Cornell Scale for Depression in Dementia and the Dementia Mood Assessment Scale (DMAS)
• Cohen-Mansfield Agitation Inventory (CMAI)

Collaborated medical evaluation 

Collaboration of multidisciplinary professionals, such as neurologists, psychologists, and psychiatrists in ruling out underlying medical, and mental health conditions, and medical side effects potentially resulting in mood changes, whilst developing a holistic care plan.  

Caregiver input 

Due to the limited time in clinical sessions, caregivers’ participation and input are also helpful in providing valuable insight into individuals’ mood changes and behavioural patterns to facilitate proper assessment.^10,14

Management Strategies 

The management of mood changes among mixed dementia populations is multifaceted and is tailored to an individual's needs.¹⁰   

Medications 

Psychotropic medications like antidepressants, anti-anxiety, and antipsychotic drugs can be prescribed to those with severe mood and emotional struggles. Side effects should always be carefully monitored to balance their benefits. 

Non-medical interventions 

Alternative interventions such as cognitive-behavioural therapy, reminiscence therapy, animal-assisted therapy, art therapy, music therapy, and other supportive psychotherapies can assist with stress-coping, facilitate emotional outlets, and improve overall well-being.^15,16,17,18   

Physical exercises 

Regular and appropriate exercises tailored to an individual's mobility can help to reduce depression and anxiety, improve mood, and enhance overall well-being.  

Social engagement 

Despite combating social isolation and promoting emotional health, social interactions, recreational engagements, and meaningful collaborative activities can also help to maintain physical functioning and preserve cognitive abilities.  

Environmental modifications

Creating an empathetic, supportive, and calm environment with structured and familiar routines can help reduce stress and stabilise emotions. 

Role of caregivers in mood changes management 

Caregivers are vital in managing mood changes among individuals with mixed dementia, despite the aforementioned observation, reporting, and environmental support. Active listening, utilising easy-to-understand language assisted by non-verbal cues (e.g., gestures, facial expressions, and touch), as well as an extent of autonomy in decision-making, can aid in effective communication with loved ones who have mixed dementia.¹⁰

Nonetheless, caregiver self-care is also of equal importance to prevent burnout and maintain the capacity care to for your loved ones. 

Challenges and considerations 

Mood changes in mixed dementia involve challenges in differentiating overlapping symptoms from mood disorders and communication barriers. The long-term outlook for mixed dementia also comes with its complexities in lieu of the progressive cognitive, motor decline, behavioural changes, and mood fluctuations. 

Summary 

Due to the complex pathologies, mood changes among mixed dementia can be unpredictable and difficult to diagnose, as well as upsetting for individuals and their loved ones.  Managing mood changes among mixed dementia can be of significant challenge in differentiating symptoms from mood disorders, intensified by communication barriers and overlapping features. Caregivers are crucial in observing, reporting symptoms, and providing support to their loved ones. Along with the complexity involved, comprehensive assessment, ongoing monitoring, and multidisciplinary collaborative care from healthcare professionals are necessitated to provide individualised interventions, so as to enhance the well-being and quality of life of the mixed dementia population with mood and emotional challenges.