Auditory verbal hallucinations and childhood trauma subtypes across the psychosis continuum: a cluster analysis

Introduction: A strong link between voice-hearing experience and childhood trauma has been established. The aim of this study was to identify whether there were unique clusters of childhood trauma subtypes in a sample across the clinical spectrum of auditory verbal hallucinations (AVH) and to examine clinical and phenomenological features across these clusters.Methods: Combining two independent international datasets (the Netherlands and Australia), childhood trauma subtypes were examined using hierarchical cluster analysis. Clinical and phenomenological characteristics were compared across emerging clusters using MANOVA and chi-squared analyses.Results: The total sample (n = 413) included 166 clinical individuals with a psychotic disorder and AVH, 122 non-clinical individuals with AVH and 125 non-clinical individuals without AVH. Three clusters emerged: (1) low trauma (n = 299); (2) emotion-focused trauma (n = 71); (3) multi-trauma (n = 43). The three clusters differed significantly on their AVH ratings of amount of negative content, with trend-level effects for loudness, degree of negative content and degree of experienced distress. Furthermore, perceptions of voices being malevolent, benevolent and resistance towards voices differed significantly.Conclusion: The data revealed different types of childhood trauma had different relationships between clinical and phenomenological features of voice-hearing experiences. Thus, implicating different mechanistic pathways and a need for tailored treatment approaches.

Pet ownership and mental health during COVID-19 lockdown

Owning a pet has often been associated with improved mental health among owners, including enhanced quality of life, and decreased levels of depression and loneliness. The aim of this study was to identify whether owning a cat and/or dog was associated with better psychological wellbeing during a strict lockdown period in Victoria, Australia, during the COVID-19 pandemic. Data were analysed from a large-scale mental health study: the COvid-19 and you: mentaL heaLth in AusTralia now survEy (COLLATE). The impact of pet ownership on levels of resilience, loneliness and quality of life were examined in a sample of 138 pet owners and 125 non-pet owners. Hierarchical linear regression analyses indicated that pet ownership was significantly associated with poorer quality of life, but not significantly associated with resilience or loneliness, after accounting for situational factors (e.g. job loss) and mood states. Contrary to expectations, the findings suggest that during a specific situation such as a pandemic, pets may contribute to increased burden among owners and contribute to poorer quality of life.

Identifying the cognitive underpinnings of voice-hearing by comparing never, past and current voice-hearers

OBJECTIVE

The current study aimed to compare specific cognitive profiles corresponding to auditory verbal hallucinations (AVH) status and elucidate which pattern of cognitive deficits may predict voice-hearing status.

METHOD

Clinical participants with schizophrenia spectrum disorders were partitioned into: (i) current voice-hearers (n = 46), (ii) past voice-hearers (n = 37) and (iii) never voice-hearers (n = 40), and compared with 319 non-clinical controls. Cognitive assessment employed the MATRICS Consensus Cognitive Battery (MCCB), supplemented by the Delis-Kaplan Executive Function System (D-KEFS) Colour-Word Interference Test (Stroop) as a robust measure of executive function.

RESULTS

On the Visual Learning domain, current and past voice-hearers had significantly poorer performance relative to never voice-hearers, who in turn had significantly poorer performance than non-clinical controls. Current and never voice-hearers had significantly poorer performance on the Social Cognition domain relative to non-clinical controls. Current voice-hearers also had significantly poorer performance on the Inhibition domain relative to non-clinical controls. Binary logistic regression revealed that Visual Learning was the only significant cognitive predictor of AVH presence.

CONCLUSION

Visual learning, and potentially inhibition, may be viable therapeutic targets when addressing cognitive mechanisms associated with AVHs. Future research should focus on investigating additional cognitive mechanisms, employing diverse voice-hearing populations and embarking on related longitudinal studies.

Synthesis and Characterization of Shell-Cross-Linked Glycopolymer Bilayer Vesicles

Vesicles composed of self-assembled lipids or amphiphilic polymers have significant potential in applications such as delivery of cargo for therapeutics. However, they are fragile under physiological conditions such as inside living cells or the bloodstream, in which a vast number of other molecules are present in high concentrations. This is because vesicles are in dynamic equilibrium between unimers and vesicles. Therefore, the development of more robust vesicles by covalent cross-linking of the shell was focused on. Cross-linked polymer vesicles were prepared by the self-assembly of maltopentaose-b-poly(propylene glycol) followed by the reaction between divinyl sulfone and the hydroxyl group in a maltopentaose unit. It was found that two equivalents of DVS to the polymer is an optimal condition for the cross-linking without changing in size. The bilayer structures were retained after the cross-linking reactions. Importantly, the cross-linked polymer vesicles retained their size and polydispersity even in 50:50 v/v methanol/water solution. This work highlights the potential of the divinyl sulfone shell cross-link as a promising tool for stabilization of glycopolymer vesicles.

Brain connectivity in body dysmorphic disorder compared with controls: a diffusion tensor imaging study

BACKGROUND

Several neuroimaging studies have investigated brain grey matter in people with body dysmorphic disorder (BDD), showing possible abnormalities in the limbic system, orbitofrontal cortex, caudate nuclei and temporal lobes. This study takes these findings forward by investigating white matter properties in BDD compared with controls using diffusion tensor imaging. It was hypothesized that the BDD sample would have widespread significantly reduced white matter connectivity as characterized by fractional anisotropy (FA).

METHOD

A total of 20 participants with BDD and 20 healthy controls matched on age, gender and handedness underwent diffusion tensor imaging. FA, a measure of water diffusion within a voxel, was compared between groups on a voxel-by-voxel basis across the brain using tract-based spatial statistics within the FSL package.

RESULTS

Results showed that, compared with healthy controls, BDD patients demonstrated significantly lower FA (p < 0.05) in most major white matter tracts throughout the brain, including in the superior longitudinal fasciculus, inferior fronto-occipital fasciculus and corpus callosum. Lower FA levels could be accounted for by increased radial diffusivity as characterized by eigenvalues 2 and 3. No area of higher FA was found in BDD.

CONCLUSIONS

This study provided the first evidence of compromised white matter integrity within BDD patients. This suggests that there are inefficient connections between different brain areas, which may explain the cognitive and emotion regulation deficits within BDD patients.