The impact of 5-hydroxytryptophan supplementation on sleep quality and gut microbiota composition in older adults: A randomized controlled trial

BACKGROUND & AIMS

Sleep quality is a pivotal part of health and there is growing evidence on the association between gut microbiota composition and sleep quality. 5-Hydroxytryptophan (5-HTP) is known as a precursor of the sleep regulating neurotransmitter and hormone. However, efficacy of 5-HTP supplementation for improving sleep quality in older adults is unclear. Hence, the aim of this study is to assess the impact of 5-HTP supplementation on sleep quality and gut microbiota composition in older adults.

METHODS

This is a single-blinded, 12-week parallel randomized controlled trial. Thirty older adults (66 ± 3 years) in Singapore were randomly assigned to either consume or not consume 100 mg 5-HTP daily. Every 4 weeks, sleep quality was assessed via both subjective (Pittsburg Sleep Quality Index) and objective (actigraphy watch) measures. A global sleep score (GSS) was obtained from the PSQI, where a GSS>5 defines as poor sleeper while a GSS≤5 defines as good sleeper. Blood serotonin level, urine melatonin concentration, gut microbiota composition and stool short chain fatty acids (SCFA) content were assessed at week 0 and 12. This study was registered in clinicaltrials.gov as NCT04078724 (https://clinicaltrials.gov/ct2/show/NCT04078724).

RESULTS

5-HTP supplementation showed an overall favorable effect on certain sleep quality components and an increase in serum serotonin concentration. In particular, at week 12, not good sleepers but poor sleepers with 5-HTP supplementation were able to significantly improve subjective GSS (ΔSL5-HTP: -2.80 ± 1.10 min, p-value = 0.005). In addition, they showed an increase in microbiota diversity (Simpson5-HTP vs. SimpsonControl: 0.037 ± 0.032 a.u. vs. -0.007 ± 0.022 a.u.; pinteraction: 0.013) and relative abundance of SCFA producing bacteria in the gut.

CONCLUSIONS

5-HTP supplementation can improve certain sleep quality components in older adults and this benefit was more prominently observed in poor sleepers. 5-HTP was also able to improve the gut microbiota composition in poor sleepers.

The Ketamine Side Effect Tool (KSET): A comprehensive measurement-based safety tool for ketamine treatment in psychiatry

OBJECTIVES

On a background of the rapidly expanding clinical use of ketamine and esketamine for treatment of depression and other conditions, we examined safety monitoring, seeking to identify knowledge gaps relevant to clinical practice.

METHODS

An international group of psychiatrists discussed the issue of safety of ketamine and esketamine and came to a consensus on key safety gaps.

RESULTS

There is no standard safety monitoring for off-label generic ketamine. For intranasal esketamine, each jurisdiction providing regulatory approval may specify monitoring. Treatment is often provided beyond the period for which safety has been demonstrated, with no agreed framework for monitoring of longer term side effects for either generic ketamine or intranasal esketamine.

LIMITATIONS

The KSET has established face and content validity, however it has not been validated against other measures of safety.

CONCLUSIONS

We recommend the Ketamine Side Effect Tool (KSET) as a comprehensive safety monitoring tool for acute and longer term side effects.

Impact of 5-Hydroxytryptophan Supplementation on Gut Microbiota Composition of Older Adults With Different Sleep Status in Singapore: A Randomized Controlled Trial

Objectives

The gut and brain communicate bidirectionally through the gut brain axis. Lower microbial diversity has been observed in populations with sleep disturbances. 5-Hydroxytryptophan (5-HTP) is known as a potential modulator of sleep quality, while its impact on the gut remains unclear. The aim of this study was to assess the impact of 5-HTP on gut microbiota in older Singaporeans with different sleep status.

Methods

This study is a single-blinded, 12-week parallel randomized controlled trial. Thirty older adults (66 ± 3 years, mean ± SD) were randomly assigned to either consume or not consume 100 mg 5-HTP daily. Their baseline sleep status was evaluated using global sleep score (GSS): GSS ≤ 5 (good sleepers, n:17); GSS > 5 (poor sleepers: n:13). Characterization of the bacterial population from the stool samples collected at week 0 and 12 was analyzed through 16S metagenomic sequencing. Microbiota composition between GSS ≤ 5 and GSS > 5 was compared via MetaStat analysis. The main effect and interaction of 5-HTP on gut microbiota composition was evaluated by mixed analysis of variance (ANOVA).

Results

At baseline, poor sleepers have a significantly lower relative abundance of Firmicutes than good sleepers (GSS > 5: 3.78 × 10⁻¹ ± 5.43 × 10⁻²; GSS ≤ 5: 4.33 × 10⁻¹ ± 9.32 × 10⁻²; p-value: 0.048). After a 12-week consumption of 5-HTP, subjects with GSS > 5 showed an increase in α-diversity (Simpson_5-HTP vs. Simpson_Control: 0.037 ± 0.032 vs. −0.007 ± 0.022; p_interaction: 0.013). 5-HTP supplementation also showed interaction effects on the relative abundance of Bacteroidota (Bacteroidota_5-HTP vs. Bacteroidota_Control: −1.03 × 10⁻¹ ± 4.99 × 10⁻² vs. −3.06 × 10⁻² ± 4.39 × 10⁻²; p_interaction: 0.019) and Firmicutes (Firmicutes_5-HTP vs. Firmicutes_Control: 1.10 × 10⁻¹ ± 2.40 × 10⁻² vs. 2.02 × 10⁻² ± 7.82 × 10⁻²; p_interaction: 0.031). No significant changes were observed for GSS ≤ 5 group.

Conclusions

In older adults, 5-HTP consumption modulated gut microbiota composition in poor sleepers (GSS > 5). However, no influence to the gut microbiota was observed in good sleepers (GSS ≤ 5).

Funding Sources

NUS iHealthtech Microbiome in Health, Disease and Ageing.

Impact of Dietary Counselling on Mental Health and Diet Quality in Singapore Older Adults: A Randomized Controlled Trial

Objectives

As the proportion of population ages in Singapore, some of the challenges associated with mental health conditions such as depression and anxiety become common. A good nutrition has been found to be beneficial for good mental health and the provision of dietary counselling is one of the effective dietary strategies to improve their nutritional status and mental health. However, this effect has not been assessed in Singapore older adults. Therefore, this study aimed to determine the impact of dietary counselling on the mental health and diet quality of older Singaporean adults.

Methods

This was a 24-week, parallel design, randomized controlled trial where 39 older women (aged above 60 y) in Singapore were randomized in which the intervention group received dietary counselling to follow a healthy dietary pattern and the control group did not receive dietary counselling. The dietary counselling was given for 12 weeks for the intervention group and the remaining 12 weeks were for follow up. The counselling topic covered various topics on food proportioning, food label reading and several age-related diseases. Mental health questionnaire, quality of life questionnaire and sleep quality questionnaire were administered at baseline, week 12 and week 24. Participants were required to complete a 3-day food record and the diet quality was assessed using the Alternative Healthy Eating Index 2010 (AHEI-2010). All results were presented as least square mean ± SE.

Results

The intervention group observed a significant decrease in Geriatric Depression Scale over time from week 0 to week 12 and week 24 (week 0: 2.0 ± 0.5; week 12: 1.1 ± 0.5; week 24: 0.8 ± 0.3, P < 0.05) while Geriatric Anxiety Inventory and Quality of Life scores were not changed. The intervention group also showed an increase in dietary quality based on the AHEI-2010 score at week 12 (55 ± 2 to 60 ± 2) and week 24 (55 ± 2 to 61 ± 2, P < 0.05) as compared to week 0 (55 ± 2), however only week 24 was statistically significantly. The control group saw a decrease in score over time though not statistically significant (baseline: 59 ± 2; week 12: 58 ± 2; week 24: 56 ± 2).

Conclusions

The provision of dietary counselling over a period of 24 weeks may be a viable nutritional strategy to improve dietary quality and may confer benefits in the mental health outcome.

Funding Sources

Mind Science Centre, National University of Singapore (NUS)

A Southeast Asia Consensus on the Definition and Management of Treatment-Resistant Depression

INTRODUCTION

Despite the abundance of literature on treatment-resistant depression (TRD), there is no universally accepted definition of TRD and available treatment pathways for the management of TRD vary across the Southeast Asia (SEA) region, highlighting the need for a uniform definition and treatment principles to optimize the management TRD in SEA.

METHODS

Following a thematic literature review and pre-meeting survey, a SEA expert panel comprising 13 psychiatrists with clinical experience in managing patients with TRD convened and utilized the RAND/UCLA Appropriateness Method to develop consensus-based recommendations on the appropriate definition of TRD and principles for its management.

RESULTS

The expert panel agreed that "pharmacotherapy-resistant depression" (PRD) is a more suitable term for TRD and defined it as "failure of two drug treatments of adequate doses, for 4-8 weeks duration with adequate adherence, during a major depressive episode". A stepwise treatment approach should be employed for the management of PRD - treatment strategies can include maximizing dose, switching to a different class, and augmenting or combining treatments. Non-pharmacological treatments, such as electroconvulsive therapy and repetitive transcranial magnetic stimulation, are also appropriate options for patients with PRD.

CONCLUSION

These consensus recommendations on the operational definition of PRD and treatment principles for its management can be adapted to local contexts in the SEA countries but should not replace clinical judgement. Individual circumstances and benefit-risk balance should be carefully considered while determining the most appropriate treatment option for patients with PRD.

Mindfulness Awareness Practice (MAP) to Prevent Dementia in Older Adults with Mild Cognitive Impairment: Protocol of a Randomized Controlled Trial and Implementation Outcomes

BACKGROUND

With an aging population, developing non-pharmacological interventions (NPIs) to delay dementia has become critical. Apart from cognitive decline, dementia is associated with multiple pathophysiology, including increased oxidative stress, dysregulated gene expressions, cytokine, neurotrophin, and stress markers, telomere shortening, and deteriorations in brain connectivity. Although mindfulness practices have been proposed to ameliorate these biological changes, no empirical studies were conducted. We thus aimed to investigate the effects of mindfulness awareness practice (MAP) to prevent cognitive decline and improve peripheral biomarkers in community-dwelling older adults diagnosed with mild cognitive impairment (MCI).

METHODS/DESIGN

This was a single-blinded and parallel-group randomized controlled trial with two arms (intervention and active control arms), conducted over nine months. A total of 60 consenting community-dwelling older adults diagnosed with MCI were planned to be randomized in a 1:1 ratio to either the MAP or the Health Education Program (HEP). Interventions were performed weekly for the initial 12 weeks, and monthly for the subsequent six months. Outcome measures were assessed at baseline, 3-month, and 9-month post-intervention by blinded assessors. Primary outcomes were neurocognitive tests, comprehensive peripheral biomarkers, and brain imaging scans. Secondary outcomes included basic health screening measures, affective symptoms, and measures of physical functions. Linear-mixed models were used to examine the effects of MAP on these outcome measures.

SIGNIFICANCE

This is the first randomized controlled trial to systematically investigate the effects of a mindfulness intervention in improving cognitive functions and various biomarkers in community-dwelling older adults diagnosed with MCI. Our findings have the potential to inform mindfulness intervention as a novel approach to delay dementia.

A Systematic Review and Meta-Analysis of the Impact of Different Intensity of Dietary Counselling on Cardiometabolic Health in Middle-Aged and Older Adults

Dietary counselling has been identified as one of the nutritional strategies to alleviate cardiometabolic health conditions. Its effectiveness however may vary due to factors such as intensity level and provider while this has not been comprehensively studied. This systematic review and meta-analysis aimed to assess the effects of dietary counselling on the cardiometabolic health in middle-aged and older adults and the sub-group analyses with dietary counselling intensity and the provider were also assessed. Four databases including PubMed, CINAHL Plus with Full Text, Cochrane Library and EMBASE were systematically searched. Data from 22 randomised controlled trials (RCTs) were compiled and those from 9 RCTs were utilised for meta-analysis. Dietary counselling lowered total cholesterol (TC) and fasting blood sugar (FBS) but had no impact on triglycerides (TG) and low-density lipoprotein (LDL). Sub-group analysis revealed significant lowering effect of high intensity dietary counselling for TG (weighted mean difference (WMD): −0.24 mmol/L, 95% confidence intervals (CIs): −0.40 to −0.09), TC (WMD: −0.31 mmol/L, 95% CIs: −0.49 to −0.13), LDL (WMD: −0.39 mmol/L, 95% CIs: −0.61 to −0.16) and FBS (WMD: −0.69 mmol/L, 95% CIs: −0.99 to −0.40) while medium or low intensity dietary counselling did not show favouring effects. Counselling provider showed differential responses on cardiometabolic health between dietitian and all other groups. The findings from this systematic review and meta-analysis suggest that dietary counselling is a beneficial dietary strategy to improve cardiometabolic health in middle-aged and older adults with the emphasis on the counselling intensity.

Metabolic Syndrome and Cognition: Follow-Up Study of Chinese Over-55-Year-Olds

BACKGROUND/AIM

Studies of the associations of the metabolic syndrome (MetS) with cognitive function and decline are inconclusive. We investigated the associations of the MetS with cognitive functions in 823 Chinese >55-year-olds followed up over 4.5 years.

METHODS

The relationships between the MetS and baseline and follow-up z-scores of cognitive domain functions were examined using mixed model analysis.

RESULTS

There were specific inverse cross-sectional associations of single cardiometabolic risk factors with cognition, such as hyperglycemia with processing speed (p = 0.045). The MetS was negatively associated with 3 out of 4 cognitive domains (p = 0.018 to p = 0.003), and the count of cardiometabolic risk factors with all cognitive domains (p = 0.025 to p = 0.002). Longitudinally, dyslipidemia was associated with worse decline in memory and learning (p = 0.022). The count of cardiometabolic risk factors was associated with worse declines in cognition (p = 0.032 for global cognition).

CONCLUSION

Among middle-aged and older Asians, an increased number of component cardiometabolic risk factors of the MetS was associated with a worse decline in cognitive function over time.

The Impact of 5-Hydroxytryptophan Supplementation on Sleep Quality of Older Adults in Singapore: A Randomized Controlled Trial

Objectives

Sleep quality has been associated with a number of health conditions such as cognitive impairment and cardiovascular disease. 5-Hydroxytryptophan (5-HTP) is known as a precursor of the sleep regulating serotonin and melatonin. However, 5-HTP's efficacy for improving sleep in older adults is unclear. The aim of this study is to assess the impact of 5-HTP on sleep quality in older Singaporean adults.

Methods

This study is a single-blinded, 12-week parallel randomized controlled trial, where 20 older adults (67 ± 4 years, mean ± SD; 8 M, 12 F) were randomly assigned to either consume or not consume 100 mg 5-HTP daily. Sleep quality data were collected every 4 weeks via both subjective and objective measures such as Pittsburg Sleep Quality Index (PSQI) questionnaire and actigraphy watch. A global sleep score (GSS) was obtained from the PSQI, where a GSS > 5 has been validated to be associated with poor sleep quality. In addition, other sleep quality components that were also extracted include total sleep time (TST), sleep latency (SL) and sleep efficiency (SE). The main effect and interaction of 5-HTP on sleep were evaluated by repeated-measure analysis of variance (ANOVA).

Results

At baseline, subjects had an overall GSS of 5.9 ± 3.1 a.u. (5-HTP group: 6.3 ± 3.8 a.u.; Control group: 5.5 ± 2.3 a.u.) and this indicated poor sleep quality. Consumption of 5-HTP after 4 and 8 weeks showed a favorable decrease in their objective SL (SLObj) from their baseline (week 4: −18.2 ± 21.1 min; week 8: −17.8 ± 19.2 min). On the other hand, the control group did not display desirable change in SLObj (week 4: 2.4 ± 21.6 min; week 8: 1.5 ± 21.4 min). Repeated-measures ANOVA revealed a significant treatment-by-time effect between 5-HTP consumption and SLObj at week 4 (P = 0.045) and week 8 (P = 0.033), but not at week 12 (P = 0.135). A significant treatment-by-time decrease in subjective TST (−0.1 ± 0.4 hrs, P = 0.027) observed at week 12. No changes in GSS and other subjective and objective measures of sleep quality were detected.

Conclusions

Older adults had poor sleep quality and 5-HTP supplementation helped reduce sleep latency for up to 8 weeks. Prolonged effects were not observed, and this may be due to acclimation of the body to longer-term 5-HTP supplementation.

Funding Sources

NUS iHealthtech Microbiome in Health, Disease and Ageing.

Impact of Dietary Counselling on Cardiometabolic Health Outcomes and Dietary Quality in Singapore Older Adults: A Randomized Controlled Trial

Objectives

Dietary counselling is an effective nutritional strategy for improving dietary quality and cardiometabolic health, but these beneficial effects have not been well studied in older adults, especially in Asia. Therefore, this study aimed to assess the impact of dietary counselling on cardiometabolic health outcomes and dietary quality in older Singaporean adults.

Methods

This was a 12-week, parallel design, randomized controlled trial. Twenty-six women aged above 60 y were randomized where the intervention group received dietary counselling (n = 14) and the control group did not receive dietary counselling (n = 12). Anthropometric measurement, blood pressure, fasting lipid-lipoprotein, glucose and insulin levels were examined at baseline and week 12. The interactive dietary counselling sessions were conducted by a qualified nutritionist every week and each session took 60 minutes. The counselling topics included healthy eating pattern, proper food proportioning, food label reading and several age-related diseases. All participants completed a 3-day food record and the dietary quality was assessed using the Alternative Healthy Eating Index 2010 (AHEI-2010). All results were reported as least square means ± SD.

Results

A significant decrease in serum low density lipoprotein cholesterol level was detected in the intervention group (3.3 mmol/L ± 1.0 to 3.1 mmol/L ± 0.8, P < 0.05) whereas the control group unchanged (3.8 mmol/L ± 0.6 to 3.7 mmol/L ± 0.7). Moreover, although there was an increase in waist circumference in the control group (76 cm ± 7 to 80 cm ± 6, P < 0.05), no change was observed in the intervention group (76 cm ± 7 to 77 cm ± 9). Other anthropometric and cardiometabolic measurements were not changed after intervention. Both groups showed an increase in dietary quality based on the AHEI-2010 score after intervention however change was only significant in the intervention group (44.0 ± 9.1 to 48.9 ± 8.7, P < 0.05). l group, but a significant time effect was observed (P = 0.009).

Conclusions

The provision of dietary counselling confers the benefits in the cardiometabolic health outcomes and these benefits may be explained by the improvement in dietary quality in Singaporean older adults.

Funding Sources

National University of Singapore (NUS), NUS-Mind Science Centre.

Mindfulness intervention for mild cognitive impairment led to attention-related improvements and neuroplastic changes: Results from a 9-month randomized control trial

Mindfulness-based interventions can enhance cognitive abilities among older adults, thereby effectively delaying cognitive decline. These cognitive enhancements are theorized to accompany neuroplastic changes in the brain. However, this mindfulness-associated neuroplasticity has yet to be documented adequately. A randomized controlled trial was carried out among participants with mild cognitive impairment (MCI) to examine the effects of a mindfulness-based intervention on various cognitive outcomes and cortical thickness (CT) in the context of age-related cognitive impairment. Participants were assigned to a mindfulness awareness program (MAP)(n = 27) and an active control condition - health education program (n = 27). In both, they attended weekly sessions for three months and subsequently, monthly sessions for six months. Cognitive assessments and structural scans were carried out across three time-points. Whole brain analyses on CT were carried out and were supplemented with region of interest-based analyses. ROI values and cognitive outcomes were analyzed with mixed MANOVAs and followed up with univariate ANOVAs. Nine-month MAP-associated gains in working memory span and divided attention, along with an increased CT in the right frontal pole and decreased CT in the left anterior cingulate were observed. Three-month MAP-associated CT increase was observed in the left inferior temporal gyrus but did not sustain thereafter. MAP led to significant cognitive gains and various CT changes. Most of these neurobehavioral changes, may require sustained effort across nine months, albeit at a reduced intensity. MAP can remediate certain cognitive impairments and engender neuroplastic effects even among those with MCI.

The individualized prediction of cognitive test scores in mild cognitive impairment using structural and functional connectivity features

Neuropsychological assessments are essential in diagnosing age-related neurocognitive disorders. However, they are lengthy in duration and can be unreliable at times. To this end, we explored a modified connectome-based predictive modeling approach to estimating individualized scores from multiple cognitive domains using structural connectivity (SC) and functional connectivity (FC) features. Multi-shell HARDI and resting-state functional magnetic resonance imaging scans, and scores from 10 cognitive measures were acquired from 91 older adults with mild cognitive impairment. SC and FC matrices were derived from these scans and, in various combinations, entered into models along with demographic covariates to predict cognitive scores. Leave-one-out cross-validation was performed. Predictive accuracy was assessed via the correlation between predicted and observed scores (r_{predicted-observed}). Across all cognitive measures, significant r_{predicted-observed} (0.402 to 0.654) were observed from the best-predicting models. Six of these models consisted of multimodal features. For three cognitive measures, their best-predicting models' r_{predicted-observed} were similar to that of a model that included only demographic covariates- suggesting that SC and/or FC features did not contribute significantly on top of demographics. Cross-prediction models revealed that the best-predicting models were similarly accurate in predicting scores of related cognitive measures- suggesting their limited specificity in predicting cognitive scores. Generally, multimodal connectomes together with demographics, can be exploited as sensitive markers, though with limited specificity, to predict cognitive performance across a spectrum in multiple cognitive domains. In certain situations, it may not be worthwhile to acquire neuroimaging data, considering that demographics alone can be similarly accurate in predicting cognitive scores.

Mindfulness practice alters brain connectivity in community-living elders with mild cognitive impairment

AIM

There is increasing evidence that mild cognitive impairment (MCI) is associated with widespread brain dysconnectivity. Mindfulness practice, which involves focused attention to experience the present moment in a purposeful way, has been shown to confer positive psychological and functional brain changes in healthy practitioners. It is unclear whether mindfulness practice could improve functional brain connectivity in older adults with cognitive impairment.

METHODS

Forty-seven participants with MCI were randomized into two groups: a mindfulness practice group and a control group. Functional magnetic resonance imaging of the brain and neurocognitive tests were performed before and after the 3-month intervention. A temporal efficiency analysis approach was used to examine the spatiotemporal networks of the brain.

RESULTS

Participants in the mindfulness group had significantly better temporal global efficiency than controls after 3-months of intervention. Localized changes of temporal nodal properties were present in the right cingulate gyrus, insula, and left superior temporal gyrus. Together, these results suggest greater information transmission efficiency at both the global and local spatiotemporal level. In terms of cognitive function, verbal recognition memory improved in the mindfulness group compared to the controls.

CONCLUSION

Elders who practiced mindfulness had better brain network efficiency and neurocognitive function relative to controls in this study, suggesting that mindfulness may be of benefit to aging adults with early cognitive degeneration.

Development of the Ketamine Side Effect Tool (KSET)

BACKGROUND

Currently, no specific, systematic assessment tool for the monitoring and reporting of ketamine-related side effects exists. Our aim was to develop a comprehensive Ketamine Side Effect Tool (KSET) to capture acute and longer-term side effects associated with repeated ketamine treatments.

METHODS

Informed by systematic review data and clinical research, we drafted a list of the most commonly reported side effects. Face and content validation were obtained via feedback from collaborators with expertise in psychiatry and anaesthetics, clinical trial piloting and a modified Delphi Technique involving ten international experts.

RESULTS

The final version consisted of four forms that collect information at time points: screening, baseline, immediately after a single treatment, and longer-term follow-up. Instructions were developed to guide users and promote consistent utilisation.

LIMITATIONS

Further evaluation of feasibility, construct validity and reliability is required, and is planned across multiple international sites.

CONCLUSIONS

The structured Ketamine Side Effect Tool (KSET) was developed, with confirmation of content and face validity via a Delphi consensus process. This tool is timely, given the paucity of data regarding ketamine's safety, tolerability and abuse potential over the longer term, and its recent adoption internationally as a clinical treatment for depression. Although based on data from depression studies, the KSET has potential applicability for ketamine (or derivatives) used in other medical disorders, including chronic pain. We recommend its utilisation for both research and clinical scenarios, including data registries.

Oxytocin increases inhibitory synaptic transmission and blocks development of long-term potentiation in the lateral amygdala

Oxytocin (OT) is a neuroactive peptide that influences the processing of fearful stimuli in the amygdala. In the central nucleus of the amygdala, the activation of OT receptors alters neural activity and ultimately suppresses the behavioral response to a fear conditioned stimulus. Receptors for OT are also found in the lateral amygdala (LA), and infusion of OT into the basolateral amygdala complex affects the formation and consolidation of fear memories. Yet, how OT receptor activation alters neurons and neural networks in the LA is unknown. In this study we used whole cell electrophysiological recordings to determine how OT-receptor activation changes synaptic transmission and synaptic plasticity in the LA of Sprague-Dawley rats. Our results demonstrate that OT-receptor activation results in a 200% increase in spontaneous inhibitory transmission in the LA that leads to the activation of presynaptic GABAB receptors. The activation of these receptors inhibits excitatory transmission in the LA, blocking long-term potentiation of cortical inputs onto LA neurons. Hence, this study provides the first demonstration that OT influences synaptic transmission and plasticity in the LA, revealing a mechanism that could explain how OT regulates the formation and consolidation of conditioned fear memories in the amygdala.

NEW & NOTEWORTHY This study investigates modulation of synaptic transmission by oxytocin (OT) in the lateral amygdala (LA). We demonstrate that OT induces transient increases in spontaneous GABAergic transmission by activating interneurons in the basolateral amygdala. The resultant increase in GABA release in the LA activates presynaptic GABAB receptors on both inhibitory and excitatory inputs onto LA neurons, reducing release probability at these synapses. We subsequently demonstrate that OT modulates synaptic plasticity at cortical inputs to the LA.

Mindfulness improves inflammatory biomarker levels in older adults with mild cognitive impairment: a randomized controlled trial

Few randomized controlled trials investigated the effects of mindfulness intervention on older adults diagnosed with mild cognitive impairment (MCI). Furthermore, there have been hypotheses and theoretical mechanisms on the benefits of mindfulness intervention on biomarkers of stress, inflammation, and neuroplasticity implicated in MCI that warrant empirical evidence. We conducted a pilot randomized controlled trial to examine whether Mindful Awareness Practice (MAP) improved biomarker levels in older adults with MCI. Fifty-five community-dwelling older adults aged 60 and above were randomized into either the treatment arm, MAP, or the active control arm, the health education program (HEP). Researchers who were blinded to treatment allocation assessed the outcomes at baseline, 3-month, and 9-month follow-ups. Linear-mixed models were used to examine the effect of MAP on biomarker levels. MAP participants had significantly decreased high-sensitivity c-reactive protein (hs-CRP) levels at 9-month (β = -0.307, 95% CI = -0.559 to -0.054 P = 0.018). Exploratory sub-group analyses by sex showed significantly decreased hs-CRP in females only (β = -0.445, 95% CI = -0.700 to -0.189, P = 0.001), while stratification by MCI subtype showed hs-CRP decreased only in amnestic-MCI (aMCI) (β = -0.569, 95% CI = -1.000 to -0.133, P = 0.012). Although total sample analyses were not significant, males had significantly decreased interleukin (IL)-6 (β = -1.001, 95% CI = -1.761 to -0253, P = 0.011) and IL-1β (β = -0.607, 95% CI = -1.116 to -0.100, P = 0.021) levels at 3-month and non-significant improvements at 9-month time-point. MAP improved inflammatory biomarkers in sex- and MCI subtype-specific manners. These preliminary findings suggest the potential of mindfulness intervention as a self-directed and low-cost preventive intervention in improving pathophysiology implicated in MCI.

Electroconvulsive practice in Singapore: a cross-sectional national survey

INTRODUCTION

The use of electroconvulsive therapy (ECT) in Singapore dates back to 1947. However, there is little local information on the clinical practice of ECT and its standards. We aimed to conduct a comprehensive national survey of ECT practice in Singapore.

METHODS

A cross-sectional structured questionnaire assessing the types of ECT (e.g. electrode placement, stimulus parameters), indications, anaesthetic technique, dosing methods, monitoring of outcomes and credentialing was sent in 2015 to all ECT centres in Singapore via email to collect qualitative and quantitative data regarding ECT.

RESULTS

Data was obtained from all ECT centres (n = 6), which represented that ECT was available in 23.1% of all hospitals and 50.0% of all psychiatric specialist centres. The rate of ECT was 5.89 treatments per 10,000 residents per year, and each patient received an average of 5.4 ECT per course. Only 7.0% of ECT was administered for continuation/maintenance ECT. The most common indication for ECT was depression in 5 (83.3%) out of six centres, with schizophrenia being the second most common. In 5 (83.3%) out of six centres, ECT was brief (0.5 ms) bitemporal ECT with age-based dosing, and 93.0% of the sessions were conducted in an inpatient setting. All ECT was conducted under general anaesthesia, with propofol (66.7%) being the most common type of anaesthetic used.

CONCLUSION

The practice of ECT in Singapore was highly uniform. The rates and indications for ECT were consistent with those of other developed countries, with greater use of ECT for schizophrenia. Future advances for ECT in Singapore include the use of individualised dosing based on empirical seizure threshold titration, expanded electrode placements and increased utilisation of continuation/maintenance ECT.

Daily consumption of essence of chicken improves cognitive function: a systematically searched meta-analysis of randomized controlled trials

Essence of chicken (EC) is a dietary supplement with potential benefits on one's cognitive performance. The purpose of this meta-analysis is to evaluate the effects of consuming EC on cognitive function, applying extensively represented domains. Six databases were systematically searched to yield 1760 articles. These articles were independently screened to obtain 8 eligible articles with a pooled population of 794 subjects which is more than twice the population size considered in the previous meta-analyses. Largely, favorable effects on cognitive function were observed following daily EC intake, specifically in the working memory domain (standardized mean difference: 0.31, 95% CI: 0.16, 0.46), one of the core components in executive function which showed statistically significant results. Furthermore, the observed results were also robust to sensitivity analyses and subgroup analyses. This suggests that when consumed daily, EC may improve the mental processing aspect of cognitive function amongst the healthy population.

Art therapy is associated with sustained improvement in cognitive function in the elderly with mild neurocognitive disorder: findings from a pilot randomized controlled trial for art therapy and music reminiscence activity versus usual care

BACKGROUND

Mild cognitive impairment (MCI) is a phase in cognitive decline when it is still possible to intervene to reverse the decline. Cognitive stimulation delivered through psychosocial interventions provides both psychological intervention and social stimulation to improve cognition. A pilot open-label parallel-arms randomized controlled trial was undertaken to examine the effects of art therapy (AT) and music reminiscence activity (MRA) compared to the control, on the primary outcome of neurocognitive domain assessments in elderly people with MCI.

METHODS

Community-living elderly people with MCI (Petersen's criteria), assessed for study eligibility, were randomized using a web-based system with equal allocation to two intervention arms: AT (guided viewing of art pieces and production of visual arts) and MRA (listening, and recalling memories related to music) and a control arm (standard care without any intervention). Interventions were led by trained therapists weekly for 3 months, then fortnightly for 6 months. Neurocognitive domains (mean of memory, attention, and visuo-spatial abilities standardized scores), psychological wellbeing (subsyndromal depression and anxiety) and telomere length as a biological marker of cellular ageing, were assessed by intervention-blinded assessors at baseline, 3 months and 9 months.

RESULTS

In total, 250 people were screened and 68 were randomized and included in the analysis. In the AT arm, neurocognitive domains improved compared to the control arm at 3 months (mean difference (d) = 0.40; 90% CI 0.126, 0.679) and were sustained at 9 months (d = 0.31; 90% CI 0.068, 0.548). There was some improvement in depression and anxiety at 3 and 9 months and in telomere length at 9 months, but this was not significant. Similar improvements were observed in the MRA arm over the control arm, but they were not significant. There were no intervention-related adverse effects.

CONCLUSIONS

Art therapy delivered by trained staff as "art as therapy" and "art psychotherapy" may have been the significant contributor to cognitive improvements. The findings support cognitive stimulation for elderly people with cognitive decline and signal the need for larger studies and further investigation of carefully designed psycho-social interventions for this group.

TRIAL REGISTRATION

Clinical Trials.gov, NCT02854085 . Registered on 7 July 2016.

Baclofen acts in the central amygdala to reduce synaptic transmission and impair context fear conditioning

The two main sub-divisions of the Central amygdala (CeA), the lateral-capsular (CeA-LC) and the medial (CeA-M), contain extensive networks of inhibitory interneurons. We have previously shown that activation of GABA_B-receptors reduces excitatory transmission between axons of the pontine parabrachial nucleus and neurons of the CeA-LC by inhibiting glutamate release from presynaptic terminals¹³. Here we have characterised GABA_B-receptor activation on other excitatory and inhibitory projections within the CeA. Using whole-cell, patch-clamp recordings, we found that the GABA_B-receptor agonist baclofen significantly reduced excitatory and inhibitory transmission from all tested inputs into the CeA-LC and CeA-M. In all but one of the inputs, reductions in transmission were accompanied by an increase in paired pulse ratio, indicating that presynaptic GABA_B-receptors acted to reduce the release probability of synaptic vesicles. To examine the impact of GABA_B-receptors in the CeA on contextual fear-conditioning, we infused baclofen into the CeA immediately prior to training. Compared to vehicle-infused rats, baclofen-infused rats displayed significantly less freezing both during the final stages of the training period and at test 24 hours later. The results of this study demonstrate that, by suppressing excitatory and inhibitory transmission, activation of presynaptic GABA_B-receptors in the CeA inhibits the development of context conditioned fear.

α2-adrenoceptor-mediated inhibition in the central amygdala blocks fear-conditioning

The central amygdala is critical for the acquisition and expression of fear memories. This region receives a dense innervation from brainstem noradrenergic cell groups and has a high level of α₂-adrenoceptor expression. Using whole-cell electrophysiological recordings from rat brain slices, we characterise the role of pre-synaptic α₂-adrenoceptor in modulating discrete inhibitory and excitatory connections within both the lateral and medial division of the central amygdala. The selective α₂-adrenoceptor agonist clonidine blocked the excitatory input from the pontine parabrachial neurons onto neurons of the lateral central amygdala. In addition, clonidine blocked inhibitory connections from the medial paracapsular intercalated cell mass onto both lateral and medial central amygdala neurons. To examine the behavioural consequence of α₂-adrenoceptor-mediated inhibition of these inputs, we infused clonidine into the central amygdala prior to contextual fear-conditioning. In contrast to vehicle-infused rats, clonidine-infused animals displayed reduced levels of freezing 24 hours after training, despite showing no difference in freezing during the training session. These results reveal a role for α₂-adrenoceptors within the central amygdala in the modulation of synaptic transmission and the formation of fear-memories. In addition, they provide further evidence for a role of the central amygdala in fear-memory formation.

Temporal efficiency evaluation and small-worldness characterization in temporal networks

Numerous real-world systems can be modeled as networks. To date, most network studies have been conducted assuming stationary network characteristics. Many systems, however, undergo topological changes over time. Temporal networks, which incorporate time into conventional network models, are therefore more accurate representations of such dynamic systems. Here, we introduce a novel generalized analytical framework for temporal networks, which enables 1) robust evaluation of the efficiency of temporal information exchange using two new network metrics and 2) quantitative inspection of the temporal small-worldness. Specifically, we define new robust temporal network efficiency measures by incorporating the time dependency of temporal distance. We propose a temporal regular network model, and based on this plus the redefined temporal efficiency metrics and widely used temporal random network models, we introduce a quantitative approach for identifying temporal small-world architectures (featuring high temporal network efficiency both globally and locally). In addition, within this framework, we can uncover network-specific dynamic structures. Applications to brain networks, international trade networks, and social networks reveal prominent temporal small-world properties with distinct dynamic network structures. We believe that the framework can provide further insight into dynamic changes in the network topology of various real-world systems and significantly promote research on temporal networks.

Sleep correlates of depression and anxiety in an elderly Asian population

BACKGROUND

Research looking at the association between sleep and psychiatric symptoms in elderly Asian populations is lacking. The present study examines the sleep correlates of depression and anxiety in a sample of cognitively healthy older adults.

METHODS

The Geriatric Depression Scale, Geriatric Anxiety Inventory, and the Pittsburgh Sleep Quality Index were administered to a community sample of elderly participants (n = 107; 81 women; Mage = 71.3 years, SD = 5.7) RESULTS: Geriatric Depression Scale and Geriatric Anxiety Inventory scores are both significantly correlated with sleep disturbance. Geriatric Depression Scale scores are uniquely associated with daytime dysfunction, and Geriatric Anxiety Inventory scores are uniquely associated with perceived sleep quality, sleep latency, and global Pittsburgh Sleep Quality Index scores.

CONCLUSIONS

Depression and anxiety in a cohort of elderly Asian subjects are associated with a number of sleep-related issues; both are related to a somewhat different profile of sleep problems.

Psychosocial interventions with art, music, Tai Chi and mindfulness for subsyndromal depression and anxiety in older adults: A naturalistic study in Singapore

OBJECTIVES

Subsyndromal depression (SSD) and subsyndromal anxiety (SSA) are common in the elderly and if left untreated, contributes to a lower quality of life, increased suicide risk, disability and inappropriate use of medical services. Innovative approaches are necessary to address this public health concern. We evaluate a community-based psychosocial intervention program and its effect on mental health outcomes in Singaporean older adults.

METHOD

Elderly participants with SSD and SSA, as assessed on the Geriatric Depression Scale and Geriatric Anxiety Inventory, were included. Intervention groups include Tai Chi exercise, Art Therapy, Mindfulness Awareness Practice and Music Reminiscence Therapy. The program was divided into a single intervention phase and a combination intervention phase. Outcomes were measured with the Zung Self-Rating Depression Scale (SDS) and Zung Self-Rating Anxiety Scale (SAS) at baseline, 4 weeks, 10 weeks, 24 weeks and 52 weeks. The program had ethics board approval.

RESULTS

A hundred and one subjects (25 males, 76 females; mean age = 71 years, SD = 5.95) participated. There were significant reductions in SDS and SAS scores in the single intervention phase (P < 0.05), and these reductions remained significant at week 52, after completion of the combination intervention phase, relative to baseline (P < 0.001).

CONCLUSION

Participating in these psychosocial interventions led to a positive improvement in SSD and SSA symptoms in these elderly subjects over a year. This simple, inexpensive and culturally acceptable approach should be adequately studied and replicated in other communities.

Thyroid Autoimmune Antibodies and Major Depressive Disorder in Women

INTRODUCTION

Anti-thyroid antibodies are associated with extra-thyroid diseases such as Graves' ophthalmopathy and Hashimoto's encephalopathy. Some evidence suggests that anti-thyroid antibodies are also associated with depression. Interleukin (IL)-17 appears to play an important role in autoimmune thyroid disease. This study investigated whether specific thyroid autoantibodies and IL-17 distinguished persons with depression from non-depressed controls.

MATERIALS AND METHODS

Forty-seven adult females with non-psychotic, current major depressive disorder and 80 healthy female controls participated in this study. Thyroid peroxidase antibodies, thyroglobulin antibodies, thyroid-stimulating hormone (TSH) receptor antibodies, free T3 and T4, TSH and IL-17 were measured from the serum. Measurements were repeated to assess test-retest reliability. Receiver operating characteristic (ROC) curves were used to estimate discriminatory values of the measurements. Differences between groups and associations between the clinical and biochemical assessments were analysed.

RESULTS

Median TSH receptor antibody concentration was significantly higher in the depressed than control group (P <0.001). Area under the ROC curve was 0.80 (95% CI, 0.73 to 0.88). Higher TSH receptor antibody titres were associated with greater depression severity scores (r = 0.33, P <0.05). IL-17 levels were not associated with TSH receptor antibody levels or depression severity scores. Thyroid function and other thyroid autoantibodies were not associated with depression severity.

CONCLUSION

TSH receptor antibodies might be a biomarker of immune dysfunction in depression.

Glutamate, N-acetyl aspartate and psychotic symptoms in chronic ketamine users

RATIONALE

Ketamine, a non-competitive NMDA receptor antagonist, induces acute effects resembling the positive, negative and cognitive symptoms of schizophrenia. Chronic use has been suggested to lead to persistent schizophrenia-like neurobiological changes.

OBJECTIVES

This study aims to test the hypothesis that chronic ketamine users have changes in brain neurochemistry and increased subthreshold psychotic symptoms compared to matched poly-drug users.

METHODS

Fifteen ketamine users and 13 poly-drug users were included in the study. Psychopathology was assessed using the Comprehensive Assessment of At-Risk Mental State. Creatine-scaled glutamate (Glu/Cr), glutamate + glutamine (Glu + Gln/Cr) and N-acetyl aspartate (NAA/Cr) were measured in three brain regions-anterior cingulate, left thalamus and left medial temporal cortex using proton magnetic resonance spectroscopy.

RESULTS

Chronic ketamine users had higher levels of subthreshold psychotic symptoms (p < 0.005, Cohen's d = 1.48) and lower thalamic NAA/Cr (p < 0.01, d = 1.17) compared to non-users. There were no differences in medial temporal cortex or anterior cingulate NAA/Cr or in Glu/Cr or Glu + Gln/Cr in any brain region between the two groups. In chronic ketamine users, CAARMS severity of abnormal perceptions was directly correlated with anterior cingulate Glu/Cr (p < 0.05, r = 0.61-uncorrected), but NAA/Cr was not related to any measures of psychopathology.

CONCLUSIONS

The finding of lower thalamic NAA/Cr in chronic ketamine users may be secondary to the effects of ketamine use compared to other drugs of abuse and resembles previous reports in individuals at genetic or clinical risk of schizophrenia.

Long-Term Heavy Ketamine Use is Associated with Spatial Memory Impairment and Altered Hippocampal Activation

Ketamine, a non-competitive N-methyl-d-aspartate receptor antagonist, is rising in popularity as a drug of abuse. Preliminary evidence suggests that chronic, heavy ketamine use may have profound effects on spatial memory but the mechanism of these deficits is as yet unclear. This study aimed to examine the neural mechanism by which heavy ketamine use impairs spatial memory processing. In a sample of 11 frequent ketamine users and 15 poly-drug controls, matched for IQ, age, years in education. We used fMRI utilizing an ROI approach to examine the neural activity of three regions known to support successful navigation; the hippocampus, parahippocampal gyrus, and the caudate nucleus during a virtual reality task of spatial memory. Frequent ketamine users displayed spatial memory deficits, accompanied by and related to, reduced activation in both the right hippocampus and left parahippocampal gyrus during navigation from memory, and in the left caudate during memory updating, compared to controls. Ketamine users also exhibited schizotypal and dissociative symptoms that were related to hippocampal activation. Impairments in spatial memory observed in ketamine users are related to changes in medial temporal lobe activation. Disrupted medial temporal lobe function may be a consequence of chronic ketamine abuse and may relate to schizophrenia-like symptomatology observed in ketamine users.

Use of antidepressants in the treatment of chronic pain

There is a high prevalence of chronic pain disorders in the population and the individual and societal costs are large. Antidepressants have been used in the treatment of chronic pain and the pain-relieving effects are independent of the mood-elevating properties. We reviewed randomised-controlled trials, systematic reviews and meta-analyses of antidepressants in the treatment of chronic pain disorders which were identified through searches of MEDLINE and EMBASE. Antidepressants have proved to be effective in the treatment of fibromyalgia, chronic low back pain, diabetic neuropathy, postherpetic neuralgia and chronic headache, in particular tricyclic antidepressants (TCAs). There is emerging evidence that newer dual-action antidepressants are equally efficacious. Antidepressants provide a viable option in the management of chronic pain disorders. Further research into novel antidepressants will aid the pain clinician in optimising treatment for patients.

Assertive Community Treatment (ACT) in Singapore: a 1-year follow-up study

INTRODUCTION

Assertive Community Treatment (ACT) provides community-based treatment to patients with severe and persistent psychiatric illnesses, so that they may continue to live and function in the community as they receive psychiatric care. This study aimed to examine the effects of ACT on the outcome of patients over a 1-year period in an Asian population.

MATERIALS AND METHODS

This naturalistic and retrospective cohort study examined the effects of ACT on 100 patients who had completed 1 year of ACT. Parameters used to measure primary outcome were i) number of admissions (NOA) and ii) total length of stay (LOS) in days. Secondary outcome compared the employment status of patients before and after ACT. Paired sample analyses were performed using SPSS.

RESULTS AND DISCUSSION

The mean reduction in NOA 1 year post-ACT was 57.1%. The mean reduction in LOS 1 year post-ACT was 61.9%. The median reduction for NOA and LOS were both statistically significant (P <0.01). Thirty-seven patients were employed compared to 6 before the programme, a statistically significant effect on employment (odds ratio 9.69, P <0.01).

CONCLUSIONS

ACT appears effective in reducing the frequency and duration of admissions for patients in Singapore. The employment status of patients also showed improvement over the course of study.