No lower cognitive functioning in older adults with attention-deficit/hyperactivity disorder.

BACKGROUND: Research illustrates cognitive deficits in children and younger adults with attention-deficit/hyperactivity disorder (ADHD). Few studies have focused on the cognitive functioning in older adults. This study investigates the association between ADHD and cognitive functioning in older adults. METHODS: Data were collected in a cross-sectional side study of the Longitudinal Aging Study Amsterdam (LASA). A diagnostic interview to diagnose ADHD was administered among a subsample (N = 231, age 60-94). ADHD symptoms and diagnosis were assessed with the Diagnostic Interview for ADHD in Adults (DIVA) 2.0. Cognitive functioning was assessed with tests in the domains of executive functioning, information processing speed, memory, and attention/working memory. RESULTS: Regression analyses indicate that ADHD diagnosis and ADHD severity were only negatively associated with cognitive functioning in the attention/working memory domain. When adjusting for depression, these associations were no longer significant. CONCLUSION: The study shows that ADHD in older adults is associated with lower cognitive functioning in the attention/working memory domain. However, this was partly explained by depressive symptoms.

Hypothalamic-pituitary-adrenal axis activity in older persons with and without a depressive disorder.

BACKGROUND: Altered functioning of the hypothalamic-pituitary-adrenal axis (HPA-axis) has been associated with depression, but findings have been inconsistent. Among older depressed persons, both hyperactivity and hypo-activity of the HPA-axis were demonstrated. However, most studies were population-based studies, with single cortisol measurements, lacking insight into diurnal patterns of HPA-axis functioning. We aim to provide insight into functioning of the HPA-axis, assessed by various salivary cortisol samples, in depressed older adults and non-depressed controls. METHODS: Data were derived from the Netherlands Study of Depression in Older Persons. Cortisol levels of older persons without a lifetime diagnosis of depression and/or anxiety (n=109) were compared with older persons with a 6-month major depression diagnosis (n=311). ANCOVA analyses and random coefficient analysis on the four morning cortisol samples were performed. A possible U-shaped association between cortisol and depression status was examined. RESULTS: Depressed older persons showed higher morning cortisol levels at awakening (T1) and a less dynamic awakening response compared to non-depressed older persons. Dexamethasone suppression did not differ across groups. No U-shaped association between HPA-axis activity and depression was observed. CONCLUSION: We demonstrated a hypercortisolemic state and a diminished ability to respond to the stress of awakening among depressed older persons. Previously it was shown, that hypercortisolemic states may indicate a lifelong biological vulnerability for depression. Our findings expand on previous literature by demonstrating that in older persons the HPA-axis may become less responsive to stress, culminating in a further dysregulation of the diurnal cortisol-rhythm, superimposed on - possibly lifelong - hypercortisolemic states.