Detection of Neuroinflammation Induced by Typhoid Vaccine Using Quantitative Magnetization Transfer MR: A Randomized Crossover Study

BACKGROUND

The role of neuroinflammation in psychiatric disorders is not well-elucidated. A noninvasive technique sensitive to low-level neuroinflammation may improve understanding of the pathophysiology of these conditions.

PURPOSE

To test the ability of quantitative magnetization transfer (QMT) MR at 3 T for detection of low-level neuroinflammation induced by typhoid vaccine within a clinically reasonable scan time.

STUDY TYPE

Randomized, crossover, placebo-controlled.

SUBJECTS

Twenty healthy volunteers (10 males; median age 34 years).

FIELD STRENGTH/SEQUENCE

Magnetization prepared rapid gradient-echo and MT-weighted 3D fast low-angle shot sequences at 3 T.

ASSESSMENT

Participants were randomized to either vaccine or placebo first with imaging, then after a washout period received the converse with a second set of imaging. MT imaging, scan time, and blood-based inflammatory marker concentrations were assessed pre- and post-vaccine and placebo. Mood was assessed hourly using the Profile of Mood States questionnaire. QMT parameter maps, including the exchange rate from bound to free pool (kba) were generated using a two-pool model and then segmented into tissue type.

STATISTICAL TESTS

Voxel-wise permutation-based analysis examined inflammatory-related alterations of QMT parameters. The threshold-free cluster enhancement method with family-wise error was used to correct voxel-wise results for multiple comparisons. Region of interest averages were fed into mixed models and Bonferroni corrected. Spearman correlations assessed the relationship between mood scores and QMT parameters. Results were considered significant if corrected P < 0.05.

RESULTS

Scan time for the MT-weighted acquisition was approximately 11 minutes. Blood-based analysis showed higher IL-6 concentrations post-vaccine compared to post-placebo. Voxel-wise analysis found three clusters indicating an inflammatory-mediated increase in kba in cerebellar white matter. Cerebellar kba for white matter was negatively associated with vigor post-vaccine but not post-placebo.

DATA CONCLUSION

This study suggested that QMT at 3 T may show some sensitivity to low-level neuroinflammation. Further studies are needed to assess the viability of QMT for use in inflammatory-based disorders.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

Resting-state EEG connectivity recorded before and after rTMS treatment in patients with treatment-resistant depression

Repetitive transcranial magnetic stimulation (rTMS) has shown efficacy and tolerability in Major Depressive Disorder (MDD). However, the underlying mechanisms of its antidepressant effects remain unclear. This open-label study investigated electroencephalography (EEG) functional connectivity markers associated with response and the antidepressant effects of rTMS. Resting-state EEG data were collected from 28 participants with MDD before and after a four-week rTMS course. Source-space functional connectivity between 38 cortical regions was compared using an orthogonalised amplitude approach. Depressive symptoms significantly improved following rTMS, with 43 % of participants classified as responders. While the study's functional connectivity findings did not withstand multiple comparison corrections, exploratory analyses suggest an association between theta band connectivity and rTMS treatment mechanisms. Fronto-parietal theta connectivity increased after treatment but did not correlate with antidepressant response. Notably, low baseline theta connectivity was associated with greater response. However, due to the exploratory nature and small sample size, further replication is needed. The findings provide preliminary evidence that EEG functional connectivity, particularly within the theta band, may reflect the mechanisms by which rTMS exerts its therapeutic effects.

PAM trial protocol: a randomised feasibility study of psychedelic microdosing-assisted meaning-centred psychotherapy in advanced stage cancer patients

BACKGROUND

An advanced cancer diagnosis can be associated with a significant profile of distress. Psychedelic compounds have shown clinically significant effects in the treatment of psychological distress in patients with advanced-stage cancer. Given the challenges of delivering timely and effective intervention in the advanced cancer context, it is possible that an alternative, more pragmatic, approach lies in psychedelic 'microdosing'. Microdosing refers to repeated administration of psychedelics in sub-hallucinogenic doses. The purpose of this study is to evaluate the feasibility of conducting a full-scale randomised controlled trial comparing psychedelic microdose-assisted-meaning-centred psychotherapy (PA-MCP) to standard meaning-centred psychotherapy (MCP) in New Zealand indigenous (Māori) and non-indigenous people with advanced cancer and symptoms of anxiety and/or depression. Although MCP is a well-established psychotherapeutic treatment in advanced cancer populations, the potential efficacy and effectiveness of this therapy when delivered alongside a standardised microdose regimen of a psychedelic compound have not been investigated.

METHODS

Participants with advanced-stage cancer and symptoms of anxiety and/or depression (N = 40; 20 Māori, 20 non-Māori) will be randomised under double-blind conditions to receive 7 sessions of MCP alongside 13 doses of either an LSD microdose (4-20 µg) (PA-MCP) or inactive placebo (placebo-MCP). The feasibility, acceptability, and safety of this intervention and physiological and psychological measures will be recorded at baseline, at each session of MCP, and at a 1-month and 6-month follow-up.

DISCUSSION

Our findings will evaluate the feasibility, acceptability, and safety of a larger randomised controlled trial and provide an initial indication of the potential benefits of psychedelic microdosing for psychological distress in advanced-stage indigenous and non-indigenous cancer patients.

TRIAL REGISTRATION

NZCTR, ACTRN12623000478617. Registered 11 May 2023.  https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=385810&isReview=true .

Acute Mood-Elevating Properties of Microdosed Lysergic Acid Diethylamide in Healthy Volunteers: A Home-Administered Randomized Controlled Trial

BACKGROUND

Microdosing psychedelic drugs is a widespread social phenomenon with diverse benefits claimed for mood and cognition. Randomized controlled trials have failed to support these claims, but the laboratory-based dosing in trials conducted to date may have limited ecological validity.

METHODS

Healthy male volunteers were randomized into lysergic acid diethylamide (LSD) (n = 40) and placebo (n = 40) groups and received 14 doses of either 10 μg LSD or an inactive placebo every 3 days for 6 weeks. First doses were given in a supervised laboratory setting, with other doses self-administered in a naturalistic setting. Results of safety data, blinding, daily questionnaires, expectancy, and pre-/postintervention psychometrics and cognitive tasks are presented here.

RESULTS

The most notable reported adverse event was treatment-related anxiety, which prompted the withdrawal of 4 participants from the LSD group. Daily questionnaires showed credible evidence (>99% posterior probability) of improved ratings of creativity, connectedness, energy, happiness, irritability, and wellness on dose days compared with nondose days, and these effects remained when controlling for preintervention expectancy. No questionnaire or cognitive task showed a credible change between baseline and 6-week assessment time points.

CONCLUSIONS

Microdosing LSD appears to be relatively safe in healthy adult men, notwithstanding a risk of anxiety. While microdosing elicited transient increases in scales associated with mood-elevating effects, it was not sufficient to promote enduring changes to overall mood or cognition in healthy adults. Future microdosing trials in clinical populations will require the use of active placebos to control for placebo effects and dose titration to adjust for interindividual variability in drug response.

Exploring the impact of e-learning modules and webinars on health professionals' understanding of the End of Life Choice Act 2019: a secondary analysis of Manatū Hauora - Ministry of Health workforce survey

AIM

To explore the importance of health workforce training, particularly in newly regulated healthcare practices such as assisted dying (AD). This study aims to analyse the socio-demographic factors associated with health professionals' completion of the e-learning module and attendance at the two webinars provided by the New Zealand Ministry of Health - Manatū Hauora (MH) and whether completion of the e-learning module and webinars supported health professionals' understanding of the End of Life Choices Act 2019.

METHOD

Secondary analysis of the MH workforce surveys conducted in July 2021.

RESULTS

The study findings indicate that health professionals who are older, of Pākehā/European ethnicity and work in hospice settings are more likely to complete the e-learning module, while females are more likely to attend webinars.

CONCLUSION

Despite low completion and attendance rates, the study highlights the positive association between training and health professionals' overall understanding of the Act. These results emphasise the need for enhancing training programmes to increase health professionals' knowledge and competence with AD. Furthermore, the research proposes focussing on healthcare practitioners in the early stages of their careers and not directly engaged in offering AD services, as well as Māori and Pasifika health practitioners.

Psychedelic medicines for end-of-life care: Pipeline clinical trial review 2022

OBJECTIVES

People with terminal illnesses often experience psychological distress and associated disability. Recent clinical trial evidence has stimulated interest in the therapeutic use of psychedelics at end of life. Much uncertainty remains, however, mainly due to methodological difficulties that beset existing trials. We conducted a scoping review of pipeline clinical trials of psychedelic treatment for depression, anxiety, and existential distress at end of life.

METHODS

Proposed, registered, and ongoing trials were identified from 2 electronic databases (ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform). Recent reviews and both commercial and non-profit organization websites were used to identify additional unregistered trials.

RESULTS

In total, 25 studies were eligible, including 13 randomized controlled trials and 12 open-label trials. Three trials made attempts beyond randomization to assess expectancy and blinding effectiveness. Investigational drugs included ketamine (n = 11), psilocybin (n = 10), 3,4-methylenedioxymethamphetamine (n = 2), and lysergic acid diethylamide (n = 2). Three trials involved microdosing, and fifteen trials incorporated psychotherapy.

SIGNIFICANCE OF RESULTS

A variety of onging or upcoming clinical trials are expected to usefully extend evidence regarding psychedelic-assisted group therapy and microdosing in the end-of-life setting. Still needed are head-to-head comparisons of different psychedelics to identify those best suited to specific indications and clinical populations. More extensive and rigorous studies are also necessary to better control expectancy, confirm therapeutic findings and establish safety data to guide the clinical application of these novel therapies.

Health professionals' understanding and attitude towards the End of Life Choice Act 2019: a secondary analysis of Manatū Hauora - Ministry of Health workforce surveys

AIM

To determine socio-demographic factors associated with health professionals' understanding of the End of Life Choice Act (the Act), support for assisted dying (AD), and willingness to provide AD in New Zealand.

METHOD

Secondary analysis of two Manatū Hauora - Ministry of Health workforce surveys conducted in February and July 2021.

RESULTS

Our analysis showed (1) older health professionals (age>55) had a better overall understanding of the Act than their young colleagues (age⁢35), (2) female health professionals were less likely to support and be willing to provide AD, (3) Asian health professionals were less likely to support AD compared to their Pākehā/European counterparts, (4) nurses were more likely to support AD and be willing to provide AD when compared to medical practitioners, and (5) pharmacists were more willing to provide AD when compared to medical practitioners.

CONCLUSION

Several socio-demographic factors, including age, gender, ethnicity, and professional background, are significantly associated with health professionals' support and willingness to provide AD, with likely consequences for the AD workforce availability and service delivery in New Zealand. Future review of the Act could consider enhancing the roles of those professional groups with higher support and willingness to assist in providing AD services in caring for people requesting AD.

A randomized, double-blind, placebo-controlled, hybrid parallel-arm study of low-dose naltrexone as an adjunctive anti-inflammatory treatment for major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is a leading cause of disability worldwide. The current treatments are ineffective in approximately one-third of patients, resulting in a large economic burden and reduced quality of life for a significant proportion of the global population. There is considerable evidence that increased inflammation may distinguish a sub-type of MDD, and there are no validated diagnostic tools or treatments for neuroinflammation in MDD patients. The current study aims to explore the potential role of low-dose naltrexone (LDN), a drug with purported anti-inflammatory properties in the central nervous system, as an adjunctive treatment in patients with MDD.

METHODS/DESIGN

This double-blind placebo-controlled hybrid parallel arm study enables the exploration of peripheral and central inflammatory markers with LDN as an approach to investigate inflammation as a pathophysiological contributor to MDD. Eligible participants with MDD (n = 48) will be stratified into the high and low inflammatory groups according to the levels of high-sensitivity C-reactive protein (hs-CRP) and then randomized to receive LDN or placebo for an initial 12 weeks, followed by a further 12 weeks during which all participants will receive LDN. The primary outcome measure will be the Montgomery-Åsberg Depression Rating Scale (MADRS) administered at baseline, 2 weeks, 4 weeks, 8 weeks, 12 weeks, 14 weeks, 16 weeks, 20 weeks, and 24 weeks, to assess the effectiveness of the anti-depressant response. The secondary outcomes include the use of MRI techniques including quantitative magnetization transfer (qMT), echo-planar spectroscopic imaging (EPSI), and diffusion-weighted imaging (DWI) to help to elucidate the neurobiological mechanism of LDN, and the inflammatory mechanisms in action in MDD. Electroencephalography, blood samples, cognitive tasks, and additional questionnaires will also be used to determine if there is a specific profile of symptoms in individuals with inflammatory MDD. Healthy participants (n = 24) will be recruited for baseline outcome measures only, to enable comparison with patients with MDD.

DISCUSSION

This trial contributes to the literature on inflammation in MDD, including the understanding of the pathophysiology and efficacy of anti-inflammatory treatments. The investigation of inflammatory mechanisms in MDD is an important first step in the development of biomarkers to classify patient sub-groups, increase the accuracy of diagnosis, and tailor the approach to patients in clinical practice. This study may provide evidence of the benefit of LDN for the groups in whom conventional anti-depressants are ineffective and lead the way for translation into clinical practice.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12622000881730 . Registered on 21 June 2022.

An open-label feasibility study of repetitive transcranial magnetic stimulation (rTMS) for treatment-resistant depression in the New Zealand healthcare context

AIM

Major depressive disorder (MDD) poses a significant and growing burden on the New Zealand population. It is a leading cause of disability, and resistance to currently offered treatments is common. Repetitive transcranial magnetic stimulation (rTMS) is a treatment offered internationally demonstrating good efficacy and few reports of side effects. It is an intervention that requires daily visits to a clinic over a period of at least four weeks. This study aimed to investigate the effectiveness and acceptability of offering rTMS as a treatment for MDD in the setting of New Zealand healthcare systems.

METHOD

This was a naturalistic, open-label pilot study in which 30 patients with moderate-to-severe treatment-resistant MDD were treated with a course of rTMS (10 Hz) daily over the left dorsolateral prefrontal cortex for four weeks (20 sessions). Primary endpoint was response to treatment, stratified into non-responder, partial responder or responder based on the Montgomery-Åsberg Depression Rating Scale (MADRS) at the end of treatment compared to baseline (<25% reduction, 25-50% reduction, and >50% reduction respectively). Participant remission was also noted as reaching a score of ≤10.

RESULTS

Thirty participants completed the full course of treatment (16 women, mean age 47y, range 19-77y), with a mean baseline MADRS of 32.0 (range 21-48). Twelve participants were classified as responders, six as partial responders, and 12 as non-responders. Of the responders, nine were in remission at the end of treatment. Minimal side effects were reported.

CONCLUSION

Daily sessions of rTMS were successfully administered and were effective in treatment-resistant MDD. The treatment was accessible and well tolerated by the majority of the study participants and should be made available to MDD patients in New Zealand as a treatment option.