On the conundrum of cognitive impairment due to depressive disorder in older patients

Abstract

Objectives Depressive symptoms and cognitive impairment often concur in older persons. Differentiating the cause of cognitive impairment in older persons with Depressive Disorder (DD) from other diseases such as Alzheimer's Disease (AD) is challenging. The goal of this study was to characterize cognitive impairment in older persons with DD. Design Cross-sectional retrospective observational clinical cohort study using patient records from 2014 to 2018. Setting Gerontopsychiatric services of Ulm University at Bezirkskrankenhaus Gü nzburg serving as primary psychiatric care institution and tertiary referral center for psychiatric care for older persons. Partcipants DD was diagnosed according to ICD-10 criteria. When indicated by the medical history or neuropsychological assessment further diagnostic procedures were initiated. Cerebrospinal fluid (CSF) tap was routinely the first additional procedure. If patients did not consent to CSF tap or contraindications were present, 18 F-fluordesoxyglucose-PET (FDG-PET) or Amyloid-PET (Am-PET) were performed. Materials and methods Extensive neuropsychological test battery to assess cognitive profile. Results 457 subjects were diagnosed with DD (DD-all; age 50-94; 159 males, 298 females). Biomarkers were assessed in 176 persons; in 90 of these subjects AD-biomarkers were negative (DD-BM-; age 54-89; 40 males, 50 females), and in 86 subjects at least one biomarker

Cognitive profiles in persons with depressive disorder and Alzheimer’s disease

“…Performance in both patients with AD and patients with DD is below normal. Results in healthy controls have been reported in a previous analysis ( Lanza et al , 2020 ).…”

“…It has been argued that impairment of executive function is one of the hallmarks of cognitive deficits in patients with DD ( Elderkin-Thompson et al , 2004 ; Dotson et al , 2008 ). However, a recent study found other processes of memory learning and retrieval to be also impaired ( Lanza et al , 2020 ). Overall, group differences in executive function are smaller than memory recall, making these parameters ill-suited to distinguish AD and DD.…”

“…An elaborate definition of patients’ cognitive profiles above this threshold would facilitate an accurate diagnostic process even in the very mild stages of the disease. Other subgroups of these patients have been published previously ( Lanza et al , 2020 ). This study aimed to select only the patients in whom biomarkers were concordant and characteristic for AD (inclusion criterion: Abeta1-42 < 550 pg/ml, total tau > 300 pg/ml and phospho-tau > 61 pg/ml).…”

“…Despite being frequently reported, characteristics of cognitive impairment in DD are less well understood and no particular pattern is associated with the severity of DD. Accruing evidence over recent years demonstrates that patients with DD may be impaired in several cognitive tasks such as short-term memory, sustained and selective attention, alertness, cognitive flexibility and executive functions ( Williams et al , 2000 ; Landrø et al , 2001 ; Weiland-Fiedler et al , 2004 ; Paelecke-Habermann et al , 2005 ; Lanza et al , 2020 ). Moreover, different memory processes such as encoding and retrieval are also impaired ( Elderkin-Thompson et al , 2007 ; Taconnat et al , 2010 ; Mesholam-Gately et al , 2012 ).…”

Memantine can protect against inflammation-based cognitive decline in geriatric depression

“…Geriatric depression and cognitive dysfunction are often comorbid ( Charlton et al., 2014 ; Lee et al., 2007 ). Evidence of cognitive impairment has been found in up to two thirds of non-demented older adults with depression ( Lanza et al., 2020 ). Underlying inflammation is linked to increased risk for Alzheimer’s disease and treatment-resistant depression ( Zwicker et al., 2018 ).…”