Relações entre comprometimento cognitivo, sintomas depressivos e prejuízo funcional no envelhecimento normal e patológico

Abstract

The presence of cognitive impairment and depressive symptoms in older adults are commonly associated with functional outcomes, such as activities of daily living (ADL) performance. The loss of autonomy in their execution leads to functional limitations or disability. Cognitive disorders more common in old age, such as mild cognitive impairment (MCI) and dementia due to Alzheimer's disease (AD) involve progressive impairment of cognitive resources, reducing the patient’s competences to cope with environmental pressures. In this context, this work aims to investigate the contribution of different aspects of cognition and the presence of functional outcomes for depressive symptoms in older adults. Over five studies evaluated 274 participants and developed more specific measures for different aspects of ADL (Self-care, Domestic and Complex) and cognition (executive functions, episodic memory, language/semantics and memory and visuospatial abilities), validating the measures and proposing cut-off points for clinical use. By models of analysis of variance and regression, we found that cognitive factors contribute to functional outcomes in Domestic and Complex ADL, explaining 19% and 28% of variance in these models. While episodic memory and executive functions contribute to these two groups of activities language/semantic memory is associated only to the ADL Complex. Depressive symptoms exert a moderating effect on the functional performance only in Complex ADL. A detailed analysis of ADL Home and Complex suggests that each activity presents a different set of cognitive predictors, explaining between 22% to 28% of the variance of Domestic ADL and 30 to 38 % of Complex ADL. We found associations between higher intensity of mood symptoms and functional impairment in activities that rely on social contact. The results suggest that each ADL is influenced by a particular set of cognitive and behavioural predictors. Complementary analysis showed an association between fine motor dexterity with Self-care ADL in AD patients. A one-year follow-up of a smaller sample showed that baseline performance on language/semantic memory tests was associated with changes in Complex ADL, performance on Executive Functions measures with Domestic ADL and Visuospatial Abilities with Self-care ADL. The results contribute to the development of predictive models: knowing what factors contribute to the achievement of each ADL can estimate what will be the functional deficits presented by the subject in a longitudinal perspective, allowing the development of tailored rehabilitation routines according to the patient’s functional profile.