Psychosis

Psychosis is a debilitating trans-diagnostic syndrome characterized by hallucinations and delusions (Rehm and Shield 2019). The thalamus and its cortical connections play a crucial role in the pathophysiology of psychosis (Onofrj et al. 2023; Moustafa et al. 2017). However, despite often referred to as one structure, the thalamus is composed of separate nuclei with distinct cortical connections (Sherman and Guillery 2006). Recent investigations revealed lower volumes of only the medial thalamic subnuclei in first-episode psychosis patients (Thalhammer et al., 2023, in revision). Correspondingl

…may be a potential mechanism for psychosis. Current studies emphasize parvalbumin-positive (PV+) GABAergic interneurons as a key component in the development of schizophrenia symptoms, with reduced PV protein levels found in cortical PV+ interneurons in individuals with schizophrenia. Rodent models of schizophrenia indicate that the medial prefrontal cortex (mPFC) is the main structure where PV neurons exhibit aberrant function. However, it is still

…This ability is impaired in psychosis, which may be related to delusional symptoms. We studied how psychotomimetic dose of dizocilpine affects coordination between spatial and temporal aspects of learned behavioral sequences in rats. On a four-arm plus maze rats learned to visit in an ordered sequence three rewarded arms interleaved by repeated visits to the start arm. Behavior was assessed in 14 rats under three doses of dizocilpine (0.05 mg/kg, 0.1 mg/kg, and 0.125

Second generation antipsychotics (SGAs) are the first line treatment for psychosis and schizophrenia. SGAs are efficacious in reducing symptoms of these neuropsychiatric conditions; however, they are associated with metabolic side-effects that can be detrimental to a patient’s health and well-being. Patient’s taking SGAs have a three-fold increased risk of developing metabolic syndrome (MetS). MetS includes the development of type 2 diabetes, unprecedented weight gain, and dyslipidaemia. We hypothesised that SGAs disrupt mitochondrial function in the brain and periphery, and this may explain t

…and neurobiological features of psychosis. The aim of the present study was to investigate the relationship between extracellular dopamine levels, as quantified by the dopamine D2/3 receptor agonist ligand [11C]-(+)-PHNO, and confidence with which conditioned auditory percepts are reported.To this end, ten healthy volunteers (2m, 8f) completed a cross-modal sensory conditioning task after undergoing a bolus plus constant infusio

Magnetic Resonance Imaging has advanced our understanding of the neuroanatomical basis of psychosis. However, persistent challenges, including underpowered datasets, recruitment difficulties, high costs, and an overrepresentation of Western populations, hinder progress. Here, we introduce the Psychosis MRI Shared Data Resource (Psy-ShareD), a new open-access repository that aims to address these challenges by harmonising MRI datasets from labs around the world, to build a large globally representative resource. Psy-ShareD provides easily accessible and curated data, allowing a wide variety of

Individuals with depression, psychosis and clinically high risk for psychosis face cognitive decline and show altered functional connectivity in resting-state networks. An unsupervised machine-learning method, sparse partial least squares analysis (SPLS) captures latent variables from clinical features and brain mechanisms, allowing the examination of relationships between functional connectivity and cognitive functions across disorders. This study aimed to explore relationships between functional connectivity, cognitive domains and study groups using SPLS. 990 participants with recent-onset p

…how it can help us predict symptoms of psychosis, and even tap into the neural basis of hallucinations.

Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) share similarities in pathology and clinical presentation and come under the umbrella term of Lewy body dementias (LBD). Fluctuating cognition is a key symptom in LBD and manifests as altered levels of alertness and attention, with a marked difference between best and worst performance. Cognition and alertness can change over seconds or minutes to hours and days of obtundation. Cognitive fluctuations can have significant impacts on the quality of life of people with LBD as well as potentially contribute to the exacerbation

…population and clinical patients with psychosis. Using data from a laboratory-based sample of healthy

…are the core symptoms of psychosis and often co-occur. Yet, different predictive-processing alterations have been proposed for these two symptom dimensions, according to which the relative weighting of prior beliefs in perceptual inference is

Contemporary Bayesian theories of the mind highlight the role of prediction errors as a driving force in learning processes and the updating of our models of the world and of ourselves. This process is postulated to manifest both at explicit levels (e.g., subjective responses) and at implicit levels (e.g., eye movements, reaction time) of behavior. We developed a novel associative learning task in immersive virtual reality, in which a cue probabilistically predicted the subsequent location of a target to which participants had to reach. Specifically, the current study (N = 30) examined: (1) wh

…may be present from the onset of psychosis in some young adults, and may even be detectable before the onset of psychosis. Given that primary prevention is the best means to prevent the onset of more chronic and severe cardiometabolic phenotypes such as C

…areas of the brain of patients with psychosis. An emerging research field has been relying on digital phenotyping tools and ecological momen