Cognitive dysfunction in elderly females with depressive symptoms

The effects of dark chocolate on cognitive performance during cognitively demanding tasks: A randomized, single-blinded, crossover, dose-comparison study

Dark chocolate, rich in polyphenols, increases cerebral blood flow and improves cognitive function. This study aimed to determine whether the consumption of chocolate with a high concentration of polyphenols helps to maintain cognitive performance during cognitively demanding tasks. In this randomized, single-blinded, crossover, dose-comparison study, 18 middle-aged adults consumed two types of chocolate (25 g each), one with a high concentration (635.0 mg) and the other with a low concentration (211.7 mg) of cacao polyphenols, and performed a cognitive task requiring response inhibition and selective attention over two time periods (15-30 min and 40-55 min after consumption, respectively). Autonomic nerve function and subjective feelings, such as fatigue and concentration, were measured before food intake and after the second task to assess the participant's state. The results showed that the average reaction time between the first and second sessions was not significantly different for either high- or low-concentration chocolate consumption. However, the percentage of correct responses was similar in the first (96.7 %) and second (96.8 %) sessions for high-concentration chocolate consumption and significantly lower for low-concentration chocolate consumption in the second (96.4 %) session than in the first session (97.3 %). Autonomic nerve function showed a significant increase in sympathetic nerve activity after the second task with high-concentration chocolate consumption, while subjective feelings showed an increase in mental fatigue for both chocolate types but a significant decrease in concentration only after the second task with low-concentration chocolate consumption. These findings suggest that dark chocolate consumption contributes to the maintenance of performance and concentration in continuous and demanding cognitive tasks.

Functional status of thyroid and cognitive functions after menopause

Background

Thyroid activity plays a role in cognition. However, the relation between the functional state of thyroid and neuropsychiatric changes proceeding with age among people without clinical symptoms of thyroid dysfunction is still unknown. The aim of this study was analysis of cognitive function levels in reference to thyroid examination: thyroid-stimulating hormone (TSH), total thyroxin (TT4), triiodothyronine (TT3), free thyroxin (FT4), free triiodothyronine (FT3), thyroperoxidase antibodies (TPO-AB), and thyroglobulin antibodies (Tg-AB), TSH receptor antibodies (AB-TSHR) in women after menopause.

Material/Methods

A group of 383 women was recruited for the study. The inclusion criteria were: minimum two years after the last menstruation and no dementia signs on Montreal Cognitive Assessment (MoCA). Computerized battery of Central Nervous System Vital Signs (CNS VS) test was used to diagnostic cognitive functions. The blood plasma values were determined: TSH, FT3, FT4, TT3, TT4, TPO-AB, Tg-AB, and AB-TSHR. Statistical analysis was performed using Pearson’s correlation coefficient and analysis of variance in STATISTICA software.

Results

In women after menopause, TSH was negatively correlated with NCI results, executive functions, complex attention, and cognitive flexibility. FT4 was positively correlated with results of psychomotor speed. TT3 and TT4 were negatively correlated with results of memory and verbal memory. Furthermore, TT4 was negatively correlated with NCI, executive functions, and cognitive flexibility. TPO-AB was negatively correlated with results of memory, verbal memory, and psychomotor speed. Tg-AB was positively correlated with results of reaction time. AB-TSHR was negatively correlated with NCI results, memory, executive functions, psychomotor speed, complex attention, and cognitive flexibility.

Conclusions

Our study supports the importance of thyroid functionality in cognitive functioning in a group of women after menopause. The values of TSH, TT3, TT4, TPO-AB, and AB-TSHR were higher and FT4 was lower in examined women. The results were poorer in examination of cognitive functions measured with a battery of CNS-VS tests.

Mechanisms underlying neurocognitive dysfunctions in recurrent major depression

Recent work shows that depression is intimately associated with changes in cognitive functioning, including memory, attention, verbal fluency, and other aspects of higher-order cognitive processing. Changes in cognitive functioning are more likely to occur when depressive episodes are recurrent and to abate to some degree during periods of remission. However, with accumulating frequency and duration of depressive episodes, cognitive deficits can become enduring, being evident even when mood improves. Such changes in cognitive functioning give depression links to mild cognitive impairment and thereby with neurodegenerative conditions, including Alzheimer’s disease, Parkinson’s disease, schizophrenia, and multiple sclerosis. Depression may then be conceptualized on a dimension of depression – mild cognitive impairment – dementia. The biological underpinnings of depression have substantial overlaps with those of neurodegenerative conditions, including reduced neurogenesis, increased apoptosis, reactive oxygen species, tryptophan catabolites, autoimmunity, and immune-inflammatory processes, as well as decreased antioxidant defenses. These evolving changes over the course of depressive episodes drive the association of depression with neurodegenerative conditions. As such, the changes in cognitive functioning in depression have important consequences for the treatment of depression and in reconceptualizing the role of depression in wider neuroprogressive conditions. Here we review the data on changes in cognitive functioning in recurrent major depression and their association with other central conditions.

Plasma cortisol in Alzheimer's disease with or without depressive symptoms

Background

Cortisol is presumed to be a risk factor for stress- and age-related disorders, such as depressive disorder and Alzheimer’s disease (AD). The aim of this study was to investigate the association of plasma cortisol concentration with AD in presence or absence of comorbid depressive symptoms.

Material/Methods

Plasma cortisol concentration was measured in 80 AD patients (35 of them with depressive symptoms), 27 elderly depressive patients without AD, and 37 elderly controls.

Results

Compared to controls, a significant increase of mean plasma cortisol was found in AD patients but not in depressive patients. Plasma cortisol was positively correlated with cognitive impairment in AD patients. We confirmed a U-shaped association between plasma cortisol and major depression and a linear association between plasma cortisol and AD without depressive symptoms. Significantly increased relative risk of disease in people with high plasma cortisol was found for AD with depressive symptoms and for AD with mild dementia.

Conclusions

Plasma cortisol reflects the degree of cognitive impairment in AD rather than the severity of comorbid depression. We confirmed that both hypercortisolemia and hypocortisolemia are associated with depressive disorder. Significant association between high plasma cortisol and AD was found, supporting the use of high plasma cortisol as a component of a panel of biochemical markers for AD with depressive symptoms as well as AD in the early stage of dementia development.

Effects of chicken essence on recovery from mental fatigue in healthy males

Background

Fatigue is a common symptom in modern society. There has been a recent resurgence of interest in traditional remedies for fatigue. Chicken essence, which is rich in anserine and carnosine, has been widely taken in Asian countries as a traditional remedy with various aims, including attenuation of physical and mental fatigue. However, the evidence for its efficacy specifically for mental fatigue remains unclear. We examined the effect of essence of chicken on mental fatigue in humans, using our established fatigue-inducing task and evaluation methods.

Material/Methods

In this placebo-controlled crossover study, 20 healthy male volunteers were randomized to receive daily oral administration of essence of chicken or placebo drink provided by Cerebos Pacific Ltd. via Suntory holdings Ltd. for 4 weeks. The participants performed 2-back test trials as a fatigue-inducing mental task and then had a rest session. Just before and after each session, they completed cognitive task trials focusing on selective attention to evaluate the level of mental fatigue.

Results

After essence of chicken intake for 1 and 4 weeks, the reaction times on the cognitive task trials after the rest session were significantly shorter than those at baseline, and significant changes were not observed with placebo intake. The reaction times before and after the fatigue-inducing session were not altered by either essence of chicken or placebo intake.

Conclusions

We showed that daily intake of essence of chicken could be effective for the recovery from mental fatigue and is a promising candidate for use as an anti-fatigue food.