Effects and mechanisms of Tai Chi on mild cognitive impairment and early-stage dementia: a scoping review.

BACKGROUND: Dementia is associated with cognitive and functional decline that significantly impacts quality of life. There is currently no cure for dementia, thus, it is important to manage dementia in the early stages and delay deterioration. Previous studies have documented a range of health benefits of Tai Chi in people with early-stage dementia, however, none have systematically integrated these effects with their underlying mechanisms. The aims of this study were to (1) identify the neurocognitive, psychological, and physical health benefits of Tai Chi oi people with early-stage dementia, and (2) explore the underlying mechanisms of these effects. METHODS: We searched systematic reviews (SRs) and randomised control trials (RCTs) on Tai Chi for adults aged 50 years and older with mild cognitive impairment (MCI) or early-stage dementia in MEDLINE, PubMed, Cochrane Library, EMBASE, and major Chinese databases. No language or publication restrictions were applied. Risk of bias was assessed. RESULTS: Eight SRs with meta-analyses and 6 additional published RCTs revealed inconsistent findings of Tai Chi on improving global cognitive function, attention and executive function, memory and language, and perceptual-motor function. There was no significant between-group difference in depressive symptoms. The results from the RCTs showed that Tai Chi can reduce arthritis pain and slow the progress of dementia. No studies on MCI or early-stage dementia investigating the underlying mechanisms of Tai Chi were identified. Instead, nine mechanistic studies on healthy adults were included. These suggested that Tai Chi may improve memory and cognition via increased regional brain activity, large-scale network functional connectivity, and regional grey matter volume. CONCLUSION: The effects of Tai Chi on neurocognitive outcomes in people with MCI and early-stage dementia are still inconclusive. Further high-quality clinical trials and mechanistic studies are needed to understand if and how Tai Chi may be applied as a successful intervention to delay deterioration and improve the quality of life in people with an increased risk of cognitive decline.

A systematic review of the health effects of yoga for people with mild cognitive impairment and dementia.

BACKGROUND: Yoga is a mind-body practice that can elicit robust health and wellbeing effects for older adults. As a result, there is increased public and academic interest into the potential benefits of yoga for older people with mild cognitive impairment (MCI) and dementia. METHODS: Literature searches in five databases (CENTRAL, PubMed and EBSCOHost indexing CINAHL Plus, PsycINFO, Psychology and Behavioural Sciences Collection) were conducted from the databases' date of inception through to 4 September 2020 to identify pre-post single and multigroup studies of yoga-based interventions involving people with MCI or dementia. Effects on cognitive, mental, and physical health were evaluated, as was safety and study quality. RESULTS: Database searches identified 1431 articles. Of these, 10 unique studies met inclusion criteria (total 421 participants). Four studies each implemented Kundalini yoga and chair yoga, while two employed Hatha yoga. Most programs ran for 12 weeks (n = 5) and compared yoga to a control group (n = 5). Most studies reported improved cognition, mood, and balance. However, these effects were marred by the high risk of bias identified in all articles. Four studies assessed safety, with one instance of dizziness reported. CONCLUSIONS: In this emerging field, these studies show that yoga may be safe and beneficial for the wellbeing of people with MCI or dementia. More high quality randomised controlled trials are needed to improve the evidence-base and overcome the limitations of existing studies.

Does tai chi improve psychological well-being and quality of life in patients with cardiovascular disease and/or cardiovascular risk factors? A systematic review.

BACKGROUND: Psychological risk factors have been recognised as potential, modifiable risk factors in the development and progression of cardiovascular disease (CVD). Tai Chi, a mind-body exercise, has the potential to improve psychological well-being and quality of life. We aim to assess the effects and safety of Tai Chi on psychological well-being and quality of life in people with CVD and/or cardiovascular risk factors. METHODS: We searched for randomised controlled trials evaluating Tai Chi for psychological well-being and quality of life in people with CVD and cardiovascular risk factors, from major English and Chinese databases until 30 July 2021. Two authors independently conducted study selection and data extraction. Methodological quality was evaluated using the Cochrane Risk of Bias tool. Review Manager software was used for meta-analysis. RESULTS: We included 37 studies (38 reports) involving 3525 participants in this review. The methodological quality of the included studies was generally poor. Positive effects of Tai Chi on stress, self-efficacy, and mood were found in several individual studies. Meta-analyses demonstrated favourable effects of Tai Chi plus usual care in reducing anxiety (SMD - 2.13, 95% confidence interval (CI): - 2.55, - 1.70, 3 studies, I2 = 60%) and depression (SMD -0.86, 95% CI: - 1.35, - 0.37, 6 studies, I2 = 88%), and improving mental health (MD 7.86, 95% CI: 5.20, 10.52, 11 studies, I2 = 71%) and bodily pain (MD 6.76, 95% CI: 4.13, 9.39, 11 studies, I2 = 75%) domains of the 36-Item Short Form Survey (scale from 0 to 100), compared with usual care alone. Tai Chi did not increase adverse events (RR 0.50, 95% CI: 0.21, 1.20, 5 RCTs, I2 = 0%), compared with control group. However, less than 30% of included studies reported safety information. CONCLUSIONS: Tai Chi seems to be beneficial in the management of anxiety, depression, and quality of life, and safe to practice in people with CVD and/or cardiovascular risk factors. Monitoring and reporting of safety information are highly recommended for future research. More well-designed studies are warranted to determine the effects and safety of Tai Chi on psychological well-being and quality of life in this population. SYSTEMATIC REVIEW REGISTRATION: International Prospective Register for Systematic Reviews (PROSPERO), CRD42016042905. Registered on 26 August 2016.

Chinese Patent Medicine as Adjuvant for Mild-to-Moderate Active Ulcerative Colitis: A Network Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: To evaluate the effectiveness and safety of Chinese patent medicine for mild-to-moderate active ulcerative colitis (UC) using network meta-analysis (NMA). METHODS: We systematically searched PubMed, Cochrane library, Embase, Sino-Med, China National Knowledge Infrastructure (CNKI), Wanfang, and Chinese Scientific Journal Database (VIP) databases to October, 2020. We included randomized controlled trials (RCTs) on Chinese patent medicine for mild-to-moderate active UC. The main analysis was complemented by network subanalyses and standard pairwise comparisons. Statistical heterogeneity, inconsistencies, and ranking probability were also evaluated. RESULTS: The databases search identified 3222 citations, of which 33 RCTs involving 2971 patients met the inclusion criteria. A total of 15 Chinese patent medicines were analyzed. The overall quality of the included studies was low. Pairwise meta-analysis showed that Chinese patent medicine was superior to Mesalazine in improving disappearances of clinical symptoms, recurrence rate, and Mayo score. Based on decreases in adverse events, results from NMA showed that Xilei powder plus Mesalazine was more effective than other drugs. Other NMA results indicated that Danshen freeze-dried powder plus Mesalazine (RR: 0.13; 95% CI, 0.02-0.78) and Kangfuxin lotion plus Mesalazine (RR: 0.24; 95% CI, 0.07-0.57) were superior to Mesalazine in decreasing recurrence rate. Another NMA result indicated that Kangfuxin lotion plus Mesalazine (RR: 0.00; 95% CI, 0.00-0.02) and Zhi Kang capsule plus Mesalazine (RR: 0.00; 95% CI, 0.00-0.02) were superior to Mesalazine in increasing the disappearance of tenesmus. CONCLUSION: In the probability sorting, Xilei powder combined with Mesalazine ranked first for having the fewest adverse events, Maintaining Intestines Antidiarrheal Pills combined with Mesalazine ranked first for having the lowest recurrence rate, Xilei powder combined with Mesalazine ranked first for improving disappearance rate of mucopurulent bloody stool/abdominal pain, and Kangfuxin lotion combined with Mesalazine ranked first for improving the disappearance rate of diarrhea/tenesmus. However, there is a lack of direct comparisons among Chinese patent medicines for UC. More multiarm RCTs are needed in the future to provide direct comparative evidence.

Medicinal cannabis for psychiatric disorders: a clinically-focused systematic review.

BACKGROUND: Medicinal cannabis has received increased research attention over recent years due to loosening global regulatory changes. Medicinal cannabis has been reported to have potential efficacy in reducing pain, muscle spasticity, chemotherapy-induced nausea and vomiting, and intractable childhood epilepsy. Yet its potential application in the field of psychiatry is lesser known. METHODS: The first clinically-focused systematic review on the emerging medical application of cannabis across all major psychiatric disorders was conducted. Current evidence regarding whole plant formulations and plant-derived cannabinoid isolates in mood, anxiety, sleep, psychotic disorders and attention deficit/hyperactivity disorder (ADHD) is discussed; while also detailing clinical prescription considerations (including pharmacogenomics), occupational and public health elements, and future research recommendations. The systematic review of the literature was conducted during 2019, assessing the data from all case studies and clinical trials involving medicinal cannabis or plant-derived isolates for all major psychiatric disorders (neurological conditions and pain were omitted). RESULTS: The present evidence in the emerging field of cannabinoid therapeutics in psychiatry is nascent, and thereby it is currently premature to recommend cannabinoid-based interventions. Isolated positive studies have, however, revealed tentative support for cannabinoids (namely cannabidiol; CBD) for reducing social anxiety; with mixed (mainly positive) evidence for adjunctive use in schizophrenia. Case studies suggest that medicinal cannabis may be beneficial for improving sleep and post-traumatic stress disorder, however evidence is currently weak. Preliminary research findings indicate no benefit for depression from high delta-9 tetrahydrocannabinol (THC) therapeutics, or for CBD in mania. One isolated study indicates some potential efficacy for an oral cannabinoid/terpene combination in ADHD. Clinical prescriptive consideration involves caution in the use of high-THC formulations (avoidance in youth, and in people with anxiety or psychotic disorders), gradual titration, regular assessment, and caution in cardiovascular and respiratory disorders, pregnancy and breast-feeding. CONCLUSIONS: There is currently encouraging, albeit embryonic, evidence for medicinal cannabis in the treatment of a range of psychiatric disorders. Supportive findings are emerging for some key isolates, however, clinicians need to be mindful of a range of prescriptive and occupational safety considerations, especially if initiating higher dose THC formulas.

L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial.

Partial or non-response to antidepressants in Generalized Anxiety Disorder (GAD) is common in clinical settings, and adjunctive biological interventions may be required. Adjunctive herbal and nutraceutical treatments are a novel and promising treatment option. L-theanine is a non-protein amino acid derived most-commonly from tea (Camellia sinensis) leaves, which may be beneficial in the treatment of anxiety and sleep disturbance as suggested by preliminary evidence. We conducted a 10-week study (consisting of an 8-week double-blind placebo-controlled period, and 1-week pre-study and 2-week post-study single-blinded observational periods) involving 46 participants with a DSM-5 diagnosis of GAD. Participants received adjunctive L-theanine (450-900 mg) or matching placebo with their current stable antidepressant treatment, and were assessed on anxiety, sleep quality, and cognition outcomes. Results revealed that adjunctive L-theanine did not outperform placebo for anxiety reduction on the HAMA (p = 0.73) nor insomnia severity on the Insomnia Severity Index (ISI; p = 0.35). However, LT treated participants reported greater self-reported sleep satisfaction than placebo (ISI item 4; p = 0.015). Further, a separation in favour of L-theanine was noted on the ISI in those with non-clinical levels of insomnia symptoms (ISI ≤ 14; p = 0.007). No significant cognitive effects (trail making time and the modified emotional Stroop) were revealed. While this preliminary study did not support the efficacy of L-theanine in the treatment of anxiety symptoms in GAD, further studies to explore the application of L-theanine in sleep disturbance are warranted.

Intrinsic EEG and task-related changes in EEG affect Go/NoGo task performance.

Substantial research into the brain dynamics underlying cognitive functioning during tasks links the brain's EEG activity to the stimulus-evoked ERP activity. This study focused on examining how the resting state intrinsic EEG, and the change from rest to the task, affect these stimulus-response processes. Forty young adults (aged 20.3 ±â€¯2.3 years) had EEG recorded during eyes-closed (EC) and eyes-open (EO) resting states, and then during an auditory Go/NoGo task. Amplitude in the delta to beta bands was analyzed for the overall resting state EEG, the reactive change from EC to EO, and for the change from EO to the task (termed task-related change here). The relationships between these EEG measures and Go/NoGo behavioral outcomes and ERPs were assessed. Greater resting state delta and theta amplitudes were linked to Go N1-1 enhancements, but only resting state delta correlated with the NoGo N1-1. These relationships replicate previous data and highlight the functional relevance of low frequency intrinsic activity in attentional processes. However, delta increases from EO to the task predicted poorer Go response accuracy and variability, and enhanced Go Slow Wave (SW) positivity. This increase in delta, and smaller alpha-1 increments, were associated with longer mean RTs. Theta increases predicted larger Go N1-1 amplitudes, but lower NoGo accuracy rates, while beta-1 increments were predictive of NoGo SW negativity. These novel effects suggest that task-related EEG changes impact decision-making and cognitive control processes, and subsequent behavioral performance.

EEG phase states at stimulus onset in a variable-ISI Go/NoGo task: Effects on ERP components.

Previous EEG-ERP dynamics studies found non-random "preferred" EEG phases at stimulus onset in a fixed interstimulus interval (ISI) equiprobable auditory Go/NoGo paradigm, with substantial effects on ERP components. Here we changed to a variable ISI task to prevent/reduce preferential phase occurrence. Discrete Fourier transforms decomposed prestimulus EEG at Cz for each trial to calculate the phase of different frequencies at stimulus onset; we combined these into the delta, theta, alpha, and beta bands, and then sorted trials into phase quartiles for each. ERPs from the raw EEG, assessed using temporal Principal Components Analyses, were examined as a function of phase at stimulus onset. Preferential phase occurrence was reduced as predicted, but random phase substantially impacted component amplitudes. For example, negativity in delta enhanced Go and NoGo P3b; and in theta reduced NoGo but not Go P3b. Overall, EEG phases at stimulus onset support differential cognitive processing in this two-choice task.

Preferred EEG brain states at stimulus onset in a fixed interstimulus interval equiprobable auditory Go/NoGo task: a definitive study.

This study examined the occurrence of preferred EEG phase states at stimulus onset in an equiprobable auditory Go/NoGo task with a fixed interstimulus interval, and their effects on the resultant event-related potentials (ERPs). We used a sliding short-time FFT decomposition of the EEG at Cz for each trial to assess prestimulus EEG activity in the delta, theta, alpha and beta bands. We determined the phase of each 2 Hz narrow-band contributing to these four broad bands at 125 ms before each stimulus onset, and for the first time, avoided contamination from poststimulus EEG activity. This phase value was extrapolated 125 ms to obtain the phase at stimulus onset, combined into the broad-band phase, and used to sort trials into four phase groups for each of the four broad bands. For each band, ERPs were derived for each phase from the raw EEG activity at 19 sites. Data sets from each band were separately decomposed using temporal Principal Components Analyses with unrestricted VARIMAX rotation to extract N1-1, PN, P2, P3, SW and LP components. Each component was analysed as a function of EEG phase at stimulus onset in the context of a simple conceptualisation of orthogonal phase effects (cortical negativity vs. positivity, negative driving vs. positive driving, waxing vs. waning). The predicted non-random occurrence of phase-defined brain states was confirmed. The preferred states of negativity, negative driving, and waxing were each associated with more efficient stimulus processing, as reflected in amplitude differences of the components. The present results confirm the existence of preferred brain states and their impact on the efficiency of brain dynamics in perceptual and cognitive processing.