Syndromic association of behavioral and psychological symptoms of dementia in Alzheimer disease and patient classification.

OBJECTIVES: To identify patient groups with Alzheimer disease (AD) according to the presence of psychological and behavioral syndromes and to determine the clinical differences among these groups. METHODS: Cross-sectional and observational study of 491 patients with probable AD whom were administered the Neuropsychiatric Inventory (NPI) at the baseline visit and reevaluated after 12 months. RESULTS: Principal component analysis (PCA) of baseline NPI data revealed three factors, including a psychosis factor (delusions, hallucinations, and aberrant motor behavior), a depressive factor (depression, anxiety, irritability, agitation, and apathy) and a hypomanic factor (euphoria and disinhibition). Cluster analysis of factor scores indicated the presence of three patient groups: one group was characterized by low scores in factors, a second group including patients with high scores in the depressive factor, and a third group that included patients with high scores in the three factors. The PCA of the NPI scores carried out after 1 year showed the persistence of the three factors. The cluster analysis of their factor scores also showed the presence of the same three patient groups but with a few differences in certain symptoms. A higher frequency of personal psychiatric history but no family history was observed in the cluster with depressive symptoms. CONCLUSIONS: Three neuropsychiatric syndromes have been identified, which have made it possible to classify patients with AD in three distinct large groups. A temporal stability is evidenced among the group with low symptoms. Patients with high scores in depressive factor or in three factors showed greater temporal instability. Certain differences among the groups suggest that different physiopathogenic mechanisms may be involved in neuropsychiatric syndromes.

Comparison of different clinical diagnostic criteria for depression in Alzheimer disease.

OBJECTIVE: Data in the literature show different estimates of the prevalence of depression in patients with Alzheimer disease (AD) when different classification systems are used. This study describes the prevalence and clinical features of depression in AD based on five different depression classification systems. METHODS: This was a cross-sectional, observational study of 491 patients with probable AD. Depression was diagnosed using five classification systems (International Classification of Diseases, 10th Revision [ICD-10], Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition [DSM-IV], Cambridge Examination for Mental Disorder of the Elderly [CAMDEX], Provisional Diagnostic Criteria for depression in AD [PDC-dAD], Neuropsychiatric Inventory [NPI]). RESULTS: The prevalence of depression was 4.9% (95% confidence interval [CI]: 3.2-7.1) according to ICD-10 criteria; 9.8% (95% CI: 7.3-12.6) according to CAMDEX; 13.4% (95% CI: 10.6-16.6) according to DSM-IV; 27.4% (95% CI: 23.6-31.5) according to PDC-dAD criteria; and 43.7% (95% CI: 39.4-48.2) when using the screening questions from the NPI depression subscale. The level of agreement between the classification systems was low to moderate (kappa <0.52). The characteristics associated with the most diagnostic disagreement were loss of confidence or self-esteem and irritability. CONCLUSIONS: This study shows that there is a high variability in the prevalence rates of depression in AD depending on the diagnostic criteria used and that there is a low rate of agreement among the diagnostic criteria analyzed. The results suggest that the use of generic diagnostic criteria such as the ICD-10, the CAMDEX, or DSM-IV provides low prevalence rates of depression in patients with AD compared with specific diagnostic criteria such as the PDC-dAD.

[Cost relation between severity of Alzheimer's disease and cognitive and functional impairment]. / Análisis de los costes de la enfermedad de Alzheimer en función del deterioro cognitivo y funcional.

BACKGROUND AND OBJECTIVE: This study aims to identify the relationship between costs of medical and social attention in patients with dementia of Alzheimer disease (AD) type and clinical and sociodemographic data of patients and their caregivers. PATIENTS AND METHOD: It was an analytic observational study in a cohort of patients diagnosed with Alzheimer's disease who received ambulatory attention. Information about the use of health-related resources was collected and costs were estimated from a societal perspective. Indirect costs were calculated using a replacement cost approach. Patients and caregivers were examined with the Mini-Mental State Examination (MMSE), the Rapid Disability Rating Scale (RDRS-2), the Neuropsychiatric Inventory (NPI), the Burden Interview (BI) and the Resource Utilization in Dementia (RUD). Patients were grouped taking into account the score obtained in the MMSE. RESULTS: A cohort of 417 patients, mean age (SD) 75.2 (6.6) years, 71% females, was studied. Disease severity levels were distributed as follows: MMSE, 26% for MMSE > 19, 66% for MMSE = 19-11, and 8% for MMSE < 11. 69% of caregivers were women, with a mean age of 57.1 (15.8) years. The cost per patient and per month was estimated to be 419.3 Euro for MMSE > 19, 641.9 Euro for MMSE = 19-11, and 1150.6 Euro for MMSE < 11. CONCLUSIONS: The societal cost of AD increases dramatically with increasing disease severity. Caregiver burden and sex as well as the marital status of patients are associated with the cost of the disease.