Distinguishing apathy and depression in dementia: A longitudinal study

Apathy and Motivation: Biological Basis and Drug Treatment

Apathy is a disabling syndrome associated with poor functional outcomes that is common across a broad range of neurological and psychiatric conditions. Currently, there are no established therapies specifically for the condition, and safe and effective treatments are urgently needed. Advances in the understanding of motivation and goal-directed behavior in humans and animals have shed light on the cognitive and neurobiological mechanisms contributing to apathy, providing an important foundation for the development of new treatments. Here, we review the cognitive components, neural circuitry, and pharmacology of apathy and motivation, highlighting converging evidence of shared transdiagnostic mechanisms. Though no pharmacological treatments have yet been licensed, we summarize trials of existing and novel compounds to date, identifying several promising candidates for clinical use and avenues of future drug development.

Apathy and depression in mild cognitive impairment: distinct longitudinal trajectories and clinical outcomes

OBJECTIVES

Apathy is a common symptom in mild cognitive impairment (MCI) and may predict progression to dementia. Little research, however, has investigated the longitudinal trajectory of apathy in patients with MCI or controlled for depression, which can mimic apathy, when examining its clinical correlates. The current study sought to address these issues.

DESIGN

A prospective longitudinal study was conducted over 3 years.

SETTING

Nine memory clinics around Australia.

PARTICIPANTS

One hundred and eighty-five patients with MCI at baseline.

MEASUREMENTS

Measures of cognition, function, neuropsychiatric symptoms, caregiver burden, and medication use were completed annually with additional assessments at 3 and 6 months. Patients were also assessed for dementia by expert clinicians at these time points.

RESULTS

Of 164 patients who completed measures of neuropsychiatric symptoms, 59 (36.0%) had apathy and 61 (37.2%) had depression. The proportion affected by apathy and overall apathy scores increased over time, in contrast to measures of depression, which remained relatively stable. Apathy was associated with incident dementia and worse cognition, function, neuropsychiatric symptoms, and caregiver burden independent of both depression and incident dementia. Depression was associated with worse function, albeit to lesser degree than apathy, and neuropsychiatric symptoms.

CONCLUSIONS

Apathy increases in MCI and is associated with worse clinical outcomes. These findings provide further evidence for apathy as a marker of clinical decline in older people and poorer outcomes across neurocognitive disorders.

Change in Purpose in Life Before and After Onset of Cognitive Impairment

Importance

Purpose in life is a critical aspect of psychological well-being that is associated with better cognitive outcomes across the continuum of dementia. To our knowledge, the natural history of purpose with onset of cognitive impairment has yet to be evaluated.

Objective

To evaluate changes in purpose in life prior to and after onset of cognitive impairment.

Design, Setting, and Participants

This cohort study used assessments of purpose in life and cognitive status from March 2006 to May 2021 in the Health and Retirement Study (HRS) and from May 2011 to November 2021 in the National Health and Aging Trends Study (NHATS).

Exposure

Cognitive impairment at each wave based on established thresholds in HRS and NHATS.

Main Outcomes and Measures

The main outcome was purpose in life, measured with the Ryff Measures of Psychological Well-Being in HRS and a validated item in NHATS.

Results

In HRS, 22 668 participants provided 50 985 assessments of purpose across all waves. In NHATS, 10 786 participants provided 53 880 assessments of purpose across all waves. In HRS, 58.3% of participants were female, with mean (SD) age of 64.76 (10.41) years at baseline; in NHATS, 57.4% were female, with mean (SD) age of 76.82 (7.71) years at baseline. Across waves, 6794 HRS participants (30%) and 4446 NHATS participants (41.2%) were in the cognitive impairment range. Accounting for demographic covariates and normative change in purpose, multilevel modeling indicated that standardized purpose in life declined significantly prior to onset of cognitive impairment (estimate for 10 years) in both HRS (b = -0.12; 95% CI, -0.17 to -0.07; P < .001) and NHATS (b = -0.10; 95% CI, -0.20 to -0.01; P = .03). Purpose declined significantly more rapidly following onset of cognitive impairment, with a standardized decline nearly 3 times larger compared with prior to impairment in HRS (b = -0.35; 95% CI, -0.41 to -0.29; P < .001) and 4 times larger in NHATS (b = -0.44; 95% CI, -0.53 to -0.34; P < .001).

Conclusions and Relevance

In this cohort study, purpose in life declined with emergence of cognitive impairment. The decline before onset was too small to be useful to detect impending impairment in clinical settings. The steeper decline following impairment suggests that individuals are aware that their purpose is declining. Purpose may be an intervention target following cognitive impairment to maintain well-being and to reduce or slow emergence of behavioral symptoms associated with low purpose.

An Update on Apathy in Alzheimer's Disease

Apathy is a complex multi-dimensional syndrome that affects up to 70% of individuals with Alzheimer's disease (AD). Whilst many frameworks to define apathy in AD exist, most include loss of motivation or goal-directed behaviour as the central feature. Apathy is associated with significant impact on persons living with AD and their caregivers and is also associated with accelerated cognitive decline across the AD spectrum. Neuroimaging studies have highlighted a key role of fronto-striatial circuitry including the anterior cingulate cortex (ACC), orbito-frontal cortex (OFC) and associated subcortical structures. Importantly, the presence and severity of apathy strongly correlates with AD stage and neuropathological biomarkers of amyloid and tau pathology. Following from neurochemistry studies demonstrating a central role of biogenic amine neurotransmission in apathy syndrome in AD, recent clinical trial data suggest that apathy symptoms may improve following treatment with agents such as methylphenidate-which may have an important role alongside emerging non-pharmacological treatment strategies. Here, we review the diagnostic criteria, rating scales, prevalence, and risk factors for apathy in AD. The underlying neurobiology, neuropsychology and associated neuroimaging findings are reviewed in detail. Finally, we discuss current treatment approaches and strategies aimed at targeting apathy syndrome in AD, highlighting areas for future research and clinical trials in patient cohorts.

The presence and severity of neuropsychiatric symptoms and their association with quality of life among patients with dementia

BACKGROUND

Neuropsychiatric symptoms are common manifestations of dementia. The presence and severity of these symptoms differ depending on different personal and contextual factors.

PURPOSE

This study aimed to investigate the presence and predictors of neuropsychiatric symptoms and the association between the severity of these symptoms and the quality of life in a sample of patients with dementia in Jordan.

METHODS

In this cross-sectional study, 112 patients with dementia residing in Jordanian nursing homes were recruited using the consecutive sampling method.

RESULTS

The mean severity of neuropsychiatric symptoms was 9.58. The most prevalent neuropsychiatric symptoms among patients were depression (61.6%), followed by irritability (55.4%), and a feeling of euphoria (54.5%). The regression analysis results indicated that gender, marital status, and dementia severity significantly predicted the neuropsychiatric symptoms severity score and explained 17.70% of the variance. A significant negative correlation between the severity of neuropsychiatric symptoms and quality of life was found.

CONCLUSION

The study's results indicate that our sample reported mild neuropsychiatric symptoms. These symptoms' high prevalence and persistence negatively impact patients' quality of life. The study's results can help mental health nurses determine the factors impacting effective treatment strategies to combat these symptoms. Future longitudinal studies are warranted to help explain the importance of early diagnosis and management of these symptoms in preventing dementia progression.