Apathy and Depression in Mild Alzheimer's Disease: A Cross-Sectional Study Using Diagnostic Criteria

Abstract

Apathy and depression are the most frequent neuropsychiatric symptoms in Alzheimer's disease (AD). In a cross-sectional observational study of 734 subjects with probable mild AD, we evaluated the prevalence of apathy and depression. After the use of specific diagnostic criteria, we tested the interaction between the two syndromes and their relation with specific comorbidities, and different functional outcomes. Depression was diagnosed using the diagnostic criteria for depression in AD, and apathy with the diagnostic criteria for apathy in neuropsychiatric disorders. According to the specific diagnostic criteria, depression had a 47.9% prevalence, while apathy prevalence was 41.6%. Apathy and depression were associated in 32.4% of patients (n = 225). 9.4% (n = 65) had only apathy, 15.4% (n = 107) had only depression, and 42.9% had no apathy and no depression (n = 298). The three most frequent depressive symptoms were fatigue or loss of energy (59.4%), decreased positive affect or pleasure in response to social contacts and activities (46.2%), and psychomotor agitation or retardation (36.9%). Concerning apathy, loss of goal-directed cognition was the most frequently altered (63.6%), followed by loss of goal-directed action (60.6%) and loss of goal-directed emotion (43.8%). Patients with both apathy and depression more frequently required a resource allowance for dependency. Neurological comorbidities were more frequent in the "apathy and depression" and "depression alone" groups (p < 0.001). Apathy and depression overlap considerably, and this might be explained by the presence of some non-specific symptoms in both diagnostic criteria. The need for social support is higher when a patient fulfills the two diagnostic criteria.

Apathy in Older Patients with Type 2 Diabetes

“…Prevalence rates for apathy, using diagnostic criteria, of 43% for Mild Cognitive Impairment and from 21-55% for mild Alzheimer's Disease in clinic-based samples have been recently published (18,27,28). The present study prevalence of 14% in diabetes is lower but possibly consistent with the relatively mild degree of cognitive impairment and the use of a valid and reliable instrument to assess apathy.…”

Depressive-like behavior observed with a minimal loss of locus coeruleus (LC) neurons following administration of 6-hydroxydopamine is associated with electrophysiological changes and reversed with precursors of norepinephrine

“…The majority of AD patients also exhibit neuropsychiatric symptoms (NPS) with depression being the most common NPS (Bhalla et al, 2009; Benoit et al, 2012; Lebedev et al, 2014). Depression associated with AD is mainly diagnosed in mild cognitive impaired (MCI) subjects, or very early in the prognosis of AD.…”

Depressive Symptoms in Clinical and Incipient Alzheimer’s Disease

“…These rates are significantly higher than the rates of depressive (7% to 11%) and apathetic (3% to 5%) symptoms reported for comparable cognitively intact elderly cohorts [4, 43], and are most clearly highlighted by a population-based study from Olmsted County [43]. Although depression and apathy may represent distinct nosological entities [44], they frequently co-occur in AD and MCI [45], and many measures of depression, such as the DSM-IV, Hamilton Depression Rating Scale (HDRS), and Beck Depression Inventory (BDI), incorporate items that explicitly assess for the presence of apathy. Although it has been postulated that amnestic MCI is more likely to represent incipient AD than non-amnestic MCI [39], similar rates of depressive and apathetic symptoms have been reported in these MCI subtypes [46, 47].…”