Anhedonia as a Potential Risk Factor of Alzheimer’s Disease in a Community-Dwelling Elderly Sample: Results from the ZARADEMP Project

Abstract

(1) Introduction: Dementia is a major public health problem, and Alzheimer’s disease (AD) is the most frequent subtype. Clarifying the potential risk factors is necessary in order to improve dementia-prevention strategies and quality of life. Here, our purpose was to investigate the role of the absence of hedonic tone; anhedonia, understood as the reduction on previous enjoyable daily activities, which occasionally is underdetected and underdiagnosed; and the risk of developing AD in a cognitively unimpaired and non-depressed population sample. (2) Method: We used data from the Zaragoza Dementia and Depression (ZARADEMP) project, a longitudinal epidemiological study on dementia and depression. After excluding subjects with dementia, a sample of 2830 dwellers aged ≥65 years was followed for 4.5 years. The geriatric mental state examination was used to identify cases of anhedonia. AD was diagnosed by a panel of research psychiatrists according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. A multivariate survival analysis and Cox proportional hazards regression model were performed, and the analysis was controlled by an analysis for the presence of clinically significant depression. (3) Results: We found a significant association between anhedonia cases and AD risk in the univariate analysis (hazard ratio (HR): 2.37; 95% CI: 1.04–5.40). This association persisted more strongly in the fully adjusted model. (4) Conclusions: Identifying cognitively intact individuals with anhedonia is a priority to implement preventive strategies that could delay the progression of cognitive and functional impairment in subjects at risk of AD.

Investigating the genetic relationship between depression symptoms and Alzheimer’s Disease in clinically diagnosed and proxy cases

“…A number of studies suggest that anhedonia may be a better predictor of dementia than depressed mood [30][31][32] . Further, several depression symptoms, such as appetite changes, psychomotor dysfunction, and sleep disruption are commonly observed in non-depressed dementia patients [33][34][35] .…”

“…As such, this heterogeneity poses challenges to researchers seeking to better understand differences in the genetic contribution to depression and its subtypes 27,28 . However, the decomposition of depression into individual symptoms has provided insight into unique patterns of genome-wide significant loci and cross-trait genetic associations, as demonstrated in a recent GWAS of depression symptoms on the Patient Health Questionnaire (PHQ-9) by Thorp et al 29 .A number of studies suggest that anhedonia may be a better predictor of dementia than depressed mood [30][31][32] . Further, several depression symptoms, such as appetite changes, psychomotor dysfunction, and sleep disruption are commonly observed in non-depressed dementia patients [33][34][35] .…”

Factor structure and sex invariance of the temporal experience of pleasure scale (TEPS) in Chinese university students and clinical population

“…Anhedonia, defined as a diminished or absent ability to experience pleasure [1], is a core symptom of several psychiatric disorders, most prominently including major depressive disorder (MDD) and schizophrenia [2][3][4]. In recent years, anhedonia has been linked to the increased risk of many other kinds of neuropsychiatric diseases, for example, Vaquero-Puyuelo D et al found that anhedonia is a risk factor for Alzheimer's disease in a longitudinal study [5]. Several scales aimed at evaluating anhedonia have been developed.…”