The relationship between habitual physical activity status and executive function in individuals with Alzheimer’s disease: a longitudinal, cross-lagged panel analysis

To determine whether habitual physical activity status specifically influences executive function change in Alzheimer’s disease (AD) over 1 year. In this longitudinal cohort study, 45 participants with AD were recruited and provided follow-up data approximately 1 year later. Executive function measures (map search task, digit symbol substitution task, controlled oral word association task, verbal fluency task) and habitual physical activity measures (Physical Activity Scale for the Elderly (PASE) and handgrip strength) were taken at baseline and follow-up. Individual composites were subsequently created. Additional demographic, lifestyle, and neuropsychiatric measures were also taken. In a structural equation model (χ2(26) = 9.84, p = .998, comparative fit index = 1.00, root mean square error of approximation = .00), a significant association was found between habitual physical activity and executive function change (β = .27, p = .04). In a cross-lagged panel analysis, a significant path was found between the PASE score and executive change (β = .22, p = .01). As higher habitual physical activity levels were associated with reduced executive function change, the promotion of low-intensity habitual physical activities in individuals with a diagnosis of AD may be warranted. Further research is needed, however, to explore the impact of habitual physical activity on the trajectory of change across cognitive domains, and how this relates to the progression of the underlying pathology associated with this disease

Cognitive function during early abstinence from opioid dependence: a comparison to age, gender, and verbal intelligence matched controls

BACKGROUND: Individuals with opioid dependence have cognitive deficits during abuse period in attention, working memory, episodic memory, and executive function. After protracted abstinence consistent cognitive deficit has been found only in executive function. However, few studies have explored cognitive function during first weeks of abstinence. The purpose of this study was to study cognitive function of individuals with opioid dependence during early abstinence. It was hypothesized that cognitive deficits are pronounced immediately after peak withdrawal symptoms have passed and then partially recover. METHODS: Fifteen patients with opioid dependence and fifteen controls matched for, age, gender, and verbal intelligence were tested with a cognitive test battery When patients performed worse than controls correlations between cognitive performance and days of withdrawal, duration of opioid abuse, duration of any substance abuse, or opioid withdrawal symptom inventory score (Short Opiate Withdrawal Scale) were analyzed. RESULTS: Early abstinent opioid dependent patients performed statistically significantly worse than controls in tests measuring complex working memory, executive function, and fluid intelligence. Their complex working memory and fluid intelligence performances correlated statistically significantly with days of withdrawal. CONCLUSION: The results indicate a rather general neurocognitive deficit in higher order cognition. It is suggested that cognitive deficit during early abstinence from opioid dependence is related to withdrawal induced neural dysregulation in the prefrontal cortex and is partly transient