Psychiatry - Research Publications
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ItemNo Preview AvailablePredictors of the placebo response in a nutraceutical randomizedcontrolled trial for depression(ELSEVIER, 2024-01)OBJECTIVE: The placebo response in depression studies is the change in symptoms amongst those who receive an inactive treatment. Many well-designed randomized controlled trials (RCTs) of depression have a high proportion of placebo responders, with little understanding as to why. The present study assesses characteristics associated with the placebo response in a nutraceutical trial with a large proportion of placebo responders. METHODS: This is a secondary analysis of a nutraceutical depression RCT which identified no overall treatment benefit relative to placebo (n = 69 in placebo group). We investigated participant characteristics such as socio-demographics, clinical features, and recruitment methods, and their association with the placebo response. Monoaminergic genetic polymorphisms were also assessed. Placebo response was measured based on change in Montgomery-Asberg Depression Rating Scale score. The association of these hypothesis-driven variables of interest and the placebo response was examined using linear mixed effects models. RESULTS: Greater levels of education, particularly pursuing post-high school education, better self-reported general health, marriage/de facto, greater improvement in the first trial week, and more failed antidepressant therapies in the current depressive episode were associated with greater placebo response. An increased placebo response was not found in those recruited via social media nor in those with concomitant antidepressant therapy. Single nucleotide polymorphisms from the tryptophan hydroxylase 1 (TPH1) gene (A779C and A218C) were weakly associated with greater placebo response, although the evidence was attenuated after accounting for multiple comparisons. CONCLUSION: This is, to our knowledge, the first study within nutraceutical research for depression to assess the association between participant characteristics and variation in the placebo response. Several variables appeared to predict the placebo response. Such findings may encourage future trial designs which could dampen placebo response, improve assay sensitivity, and allow for treatment effects to be potentially more detectable. Please cite this article as: Arnold R, Murphy-Smith J, Ng CH, Mischoulon D, Byrne GJ, Bousman CA, Stough C, Berk M, Sarris J. Predictors of the placebo response in a nutraceutical randomized controlled trial for depression. J Integr Med. 2024; 22(1): 46-53.
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ItemNeuroimaging Insights: Kava's (Piper methysticum) Effect on Dorsal Anterior Cingulate Cortex GABA in Generalized Anxiety Disorder.(MDPI AG, 2023-10-28)Generalised Anxiety Disorder (GAD) is a prevalent, chronic mental health disorder. The measurement of regional brain gamma-aminobutyric acid (GABA) offers insight into its role in anxiety and is a potential biomarker for treatment response. Research literature suggests Piper methysticum (Kava) is efficacious as an anxiety treatment, but no study has assessed its effects on central GABA levels. This study investigated dorsal anterior cingulate (dACC) GABA levels in 37 adult participants with GAD. GABA was measured using proton magnetic resonance spectroscopy (1H-MRS) at baseline and following an eight-week administration of Kava (standardised to 120 mg kavalactones twice daily) (n = 20) or placebo (n = 17). This study was part of the Kava for the Treatment of GAD (KGAD; ClinicalTrials.gov: NCT02219880), a 16-week intervention study. Compared with the placebo group, the Kava group had a significant reduction in dACC GABA (p = 0.049) at eight weeks. Baseline anxiety scores on the HAM-A were positively correlated with GABA levels but were not significantly related to treatment. Central GABA reductions following Kava treatment may signal an inhibitory effect, which, if considered efficacious, suggests that GABA levels are modulated by Kava, independent of reported anxiety symptoms. dACC GABA patterns suggest a functional role of higher levels in clinical anxiety but warrants further research for symptom benefit. Findings suggest that dACC GABA levels previously un-examined in GAD could serve as a biomarker for diagnosis and treatment response.
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ItemSmartphone-delivered multicomponent lifestyle medicine intervention for improving mental health in a nonclinical population: a randomized controlled trial.(Frontiers Media SA, 2023)OBJECTIVE: To prevent the exacerbation of mental health burdens, a growing body of research has recommended a balanced approach that emphasizes both the delivery of mental health treatments to individuals with common mental disorders (CMDs) and the strengthening of protective factors for CMDs among nonclinical populations. This randomized controlled trial (RCT) evaluated the efficacy of a smartphone-delivered multicomponent lifestyle medicine (LM) intervention, Lifestyle Hub, for improving mental health among a nonclinical population of Chinese adults. METHODS: A total of 106 participants with Patient Health Questionnaire-9 total score < 10 and Generalized Anxiety Disorder 7-Item Scale <8 were randomly assigned to either the Lifestyle Hub intervention group (LH, n = 53) or the waitlist control group (WL, n = 53). Lifestyle Hub is an 8-week smartphone-delivered multicomponent LM intervention developed based on the transtheoretical model. The intervention components included lifestyle psychoeducation, physical activity, diet and nutrition, stress management, sleep management, and motivation and goal-setting techniques. Assessments were conducted at baseline, immediate post-intervention, and 1-month follow-up (LH only). RESULTS: The linear mixed effect model based on the intention-to-treat principle indicated that Lifestyle Hub significantly improved overall mental health, depressive symptoms, anxiety symptoms, stress, insomnia severity, overall health-promoting behaviors, dietary quality, and stress management compared to the WL group at immediate post-intervention (d = 0.13-0.56). No significant between-group differences were observed in terms of functional impairment, health-related quality of life, health responsibility, physical activity level, spiritual growth, and interpersonal relations. The intervention gains in the LH group were maintained at 1-month follow-up. The LH participants indicated that Lifestyle Hub was an acceptable intervention for improving mental health, although a significantly higher level of study attrition was observed in the LH group (20.8%) relative to the WL group (5.7%). CONCLUSION: Lifestyle Hub may serve as an efficacious and acceptable intervention for improving mental health in nonclinical adult populations. To extend the benefits of LM interventions at the population level, future studies are warranted to examine a stepped-care approach to delivering LM interventions.Trial registration: This randomized controlled trial was pre-registered with ClinicalTrials.gov (NCT04295369).
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ItemNo Preview AvailableUnraveling the associations between unhealthy lifestyle behaviors and mental health in the general adult Chinese population: A cross-sectional study.(Elsevier BV, 2024-03-15)BACKGROUND: This study examined the cumulative risk of unhealthy lifestyle behaviors and the associations between overall lifestyle and common mental disorders (CMDs), insomnia, stress, health-related quality of life (HRQOL), and functional impairment. Additionally, the treatment preferences for managing CMDs and insomnia were examined. METHODS: A survey was conducted on 1487 Chinese Hong Kong adults, assessing their lifestyle behaviors (i.e., diet and nutrition, substance use, physical activity, stress management, restorative sleep, social support, and environmental exposures), mental health-related outcomes, and treatment preferences via a vignette. RESULTS: The findings revealed significant additive relationships between the number of 'worse' lifestyle domains and the risk of all outcomes. A healthier overall lifestyle was significantly associated with reduced risks of all outcomes (AORs = 0.88 to 0.93). Having healthier practices in diet and nutrition, substance use, stress management, restorative sleep, and social support domains were significantly associated with lower risks of all outcomes (AORs = 0.93 to 0.98), except that substance use was not significantly associated with stress. Physical activity was inversely associated with only depressive symptoms (AOR = 0.98), anxiety symptoms (AOR = 0.99), and stress (AOR = 0.99). Environmental exposures were not significantly associated with functional impairment but with all other outcomes (AORs = 0.98 to 0.99). Besides, lifestyle interventions (55 %) were significantly more preferred for managing CMDs and insomnia relative to psychotherapy (35.4 %) and pharmacotherapy (9.6 %). CONCLUSIONS: Our findings underscore the importance of considering lifestyle factors when managing CMDs, insomnia, stress, HRQOL, and functional impairment, with a particular emphasis on adopting a multicomponent treatment approach.
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ItemNo Preview AvailableEffect of kava (Piper methysticum) on peripheral gene expression among individuals with generalized anxiety disorder: A post hoc analysis of a randomized controlled trial(WILEY, 2023-12)Kava is a South Pacific plant-based medicine with anxiolytic properties, but little is known about the impact kava has on gene expression or whether gene expression can serve as a marker of kava response. This study aimed to determine whether kava treatment alters the expression of genes with physiological relevance to anxiety pathophysiology and whether the baseline expression of these physiologically relevant genes modifies the efficacy of kava treatment. In this post hoc analysis, we examined the expression of 48 genes relevant to the pathophysiology of anxiety collected from a double-blind randomized controlled trial that assessed the efficacy of kava treatment in generalized anxiety disorder. Peripheral blood gene expression was measured in 71 (34 kava, 37 placebo) adults at baseline and in 40 (19 kava, 21 placebo) after 8 weeks of treatment by reverse transcription polymerase chain reaction (PCR). Results revealed that kava decreased the expression of a subunit of the GABAA -rho receptor gene (GABRR2) and catechol-O-methyltransferase (COMT), a gene related to catecholamine metabolism. Kava efficacy was not found to be modified by baseline (pretreatment) expression of relevant genes. Although these results did not withstand statistical correction for multiple comparisons and require external validation, they support the notion that kava's mechanism of action includes interaction with GABAergic and catecholaminergic systems.
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ItemEffects of a high-prebiotic diet versus probiotic supplements versus synbiotics on adult mental health: The "Gut Feelings" randomised controlled trial(FRONTIERS MEDIA SA, 2023-02-06)BACKGROUND: Preliminary evidence supports the use of dietary interventions and gut microbiota-targeted interventions such as probiotic or prebiotic supplementation for improving mental health. We report on the first randomised controlled trial (RCT) to examine the effects of a high-prebiotic dietary intervention and probiotic supplements on mental health. METHODS: "Gut Feelings" was an 8-week, 2 × 2 factorial RCT of 119 adults with moderate psychological distress and low prebiotic food intake. Treatment arms: (1) probiotic supplement and diet-as-usual (probiotic group); (2) high-prebiotic diet and placebo supplement (prebiotic diet group); (3) probiotic supplement and high-prebiotic diet (synbiotic group); and (4) placebo supplement and diet-as-usual (placebo group). The primary outcome was assessment of total mood disturbance (TMD; Profile of Mood States Short Form) from baseline to 8 weeks. Secondary outcomes included anxiety, depression, stress, sleep, and wellbeing measures. RESULTS: A modified intention-to-treat analysis using linear mixed effects models revealed that the prebiotic diet reduced TMD relative to placebo at 8 weeks [Cohen's d = -0.60, 95% confidence interval (CI) = -1.18, -0.03; p = 0.039]. There was no evidence of symptom improvement from the probiotic (d = -0.19, 95% CI = -0.75, 0.38; p = 0.51) or synbiotic treatments (d = -0.03, 95% CI = -0.59, 0.53; p = 0.92). Improved anxiety, stress, and sleep were noted in response to the prebiotic diet while the probiotic tentatively improved wellbeing, relative to placebo. No benefit was found in response to the synbiotic intervention. All treatments were well tolerated with few adverse events. CONCLUSION: A high-prebiotic dietary intervention may improve mood, anxiety, stress, and sleep in adults with moderate psychological distress and low prebiotic intake. A synbiotic combination of high-prebiotic diet and probiotic supplement does not appear to have a beneficial effect on mental health outcomes, though further evidence is required. Results are limited by the relatively small sample size. CLINICAL TRIAL REGISTRATION: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372753, identifier ACTRN12617000795392.
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ItemNo Preview AvailableEfficacy of lifestyle medicine on sleep quality: A meta-analysis of randomized controlled trials.(Elsevier BV, 2023-06-01)OBJECTIVES: Randomized controlled trials (RCTs) on the efficacy of multicomponent lifestyle medicine (LM) interventions for improving sleep quality have yielded inconsistent findings. This study marks the first meta-analysis to evaluate the efficacy of multicomponent LM interventions in improving sleep quality. METHODS: We searched six online databases for RCTs that compared multicomponent LM interventions to an active or inactive control group in an adult population and assessed subjective sleep quality as a primary or secondary outcome using validated sleep measures at any post-intervention time-point. RESULTS: A total of 23 RCTs with 26 comparisons involving 2534 participants were included in the meta-analysis. After excluding outliers, the analysis revealed that multicomponent LM interventions significantly improved sleep quality at immediate post-intervention (d = 0.45) and at short-term follow-up (i.e.,
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ItemNo Preview AvailableLifestyle medicine for anxiety symptoms: A meta-analysis of randomized controlled trials.(Elsevier BV, 2022-08-01)BACKGROUND: Lifestyle medicine (LM) is gaining increasing attention as a treatment option for anxiety, but the current state of evidence has not yet been systematically examined. METHODS: Six electronic databases were systematically searched from inception to February 2022. Randomized controlled trials (RCTs) comparing the effects of multicomponent LM interventions on anxiety symptoms with either care-as-usual, waitlist, no intervention, or attention control group on anxiety symptoms were identified. RESULTS: A total of 53 RCTs with 18,894 participants were included for qualitative synthesis, in which 45 RCTs with data available were included for meta-analysis. Multicomponent LM intervention was significantly more effective than the control groups in reducing anxiety symptoms at immediate posttreatment (d = 0.19, p < .001) and at short-term follow-up (d = 0.29, p < .001). However, no significant difference at medium-term was found (p = .14), whereas more studies are needed to study the long-term effects. The subgroup analyses suggested that baseline anxiety symptoms was a significant moderator, suggesting that those with moderate level of baseline anxiety symptoms appeared to have greater improvements (d = 0.66, p < .05). LIMITATIONS: Minimal anxiety symptoms at baseline contributed to the floor effect and influenced the degree of improvement. The included RCTs had a high risk of bias in general with potential publication bias detected. CONCLUSION: The findings of this meta-analysis provided support for the positive effects of multicomponent LM interventions for anxiety symptoms. Future research is needed to determine the long-term effects of multicimponent LM and the optimal baseline anxiety severity.
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ItemNo Preview AvailableAssessing dietary, exercise, and non-pharmacological modalities within psychiatric hospitals(ELSEVIER SCIENCE INC, 2022)
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ItemN-Acetylcysteine (NAC) in Schizophrenia Resistant to Clozapine: A Double-Blind, Randomized, Placebo-Controlled Trial Targeting Negative Symptoms(OXFORD UNIV PRESS, 2022-11-18)BACKGROUND AND HYPOTHESIS: Clozapine is the most effective antipsychotic for treatment-resistant schizophrenia, yet a significant proportion of individuals on clozapine continue to experience disabling symptoms, despite being treated with an adequate dose. There is a need for adjunct treatments to augment clozapine, notably for negative and cognitive symptoms. One such potential agent is the glutathione precursor N-acetylcysteine (NAC). STUDY DESIGN: A randomized double-blind, multi-center, placebo-controlled trial for clozapine patients with enduring psychotic symptoms (n = 84) was undertaken to investigate the efficacy of adjunctive NAC (2 g daily) for negative symptoms, cognition and quality of life (QoL). Efficacy was assessed at 8, 24, and 52 weeks. STUDY RESULTS: NAC did not significantly improve negative symptoms (P = .62), overall cognition (P = .71) or quality of life (Manchester quality of life: P = .11; Assessment of quality of life: P = .57) at any time point over a 1-year period of treatment. There were no differences in reported side effects between the groups (P = .26). CONCLUSIONS: NAC did not significantly improve schizophrenia symptoms, cognition, or quality of life in treatment-resistant patients taking clozapine. This trial was registered with "Australian and New Zealand Clinical Trials" on the 30 May, 2016 (Registration Number: ACTRN12615001273572).