Schizophrenia Bulletin最新文献

Background and hypothesis: Perception integrates sensory input with prior knowledge. Alterations in how both information sources are combined may lead to the departures from consensus reality that characterize schizophrenia (SZ). One source of prior knowledge is recent experience. Visual aftereffects-perceptions of the "opposite" of previously viewed stimulus-are driven by neuronal adaptation and demonstrate how recent experience influences perception. Our recent work revealed stronger tilt (orientation) aftereffects, but not negative afterimages (luminance aftereffects) in people with SZ relating to negative symptom severity, suggesting altered adaptation is more prominent in cortical than subcortical visual systems and may be an important illness mechanism. Because different aftereffects depend differentially on adaptation at different levels of the visual hierarchy, we sought to extend findings and probe where in the cortical hierarchy neuronal adaptation is most pronounced in SZ.

Study design: Two types of motion aftereffects were measured in SZ (n = 55) and healthy controls (HC; n = 43): "first-order" aftereffects caused by luminance-defined motion that elicits strong adaptation in early visual cortex, and "higher-order" aftereffects caused by non-luminance-feature-defined motion (eg, texture) that is primarily represented in extrastriate motion-sensitive areas.

Study results: Relative to HC, SZ showed stronger first-order but not higher-order motion aftereffects. Differences were not explained by task sensitivity, response bias, visual acuity, blinks, or fixation deviations.

Conclusions: Altered neuronal adaptation in SZ is likely more pronounced at earlier (eg, V1) versus later (eg, V5/MT) stages of the visual hierarchy. Consequently, findings potentially implicate early visual cortical processing alterations in illness pathophysiology and/or clinical presentation.

Background and hypothesis: Motivational impairments are common in psychotic disorders and have implications for functioning and recovery. A key underlying mechanism is reward processing, which crucially relies on value representation (the mental representation of the subjective value of a reward). Previous studies have found altered value representation in people with psychosis using a delay discounting task, but results have been mixed, especially in affective psychosis. It is also inconclusive how value representation relates to other constructs such as symptoms and cognition.

Study design: A total of 71 participants with schizophrenia spectrum disorders (SZ), 77 with psychotic mood disorders (MP), and 42 healthy control participants (HC) performed a delay discounting task. Using hierarchical Bayesian analysis, we derived three computational parameters from the task: discounting rate (how quickly delayed rewards lose subjective value), time sensitivity (subjective perception of time), and inverse temperature (choice consistency in relation to subjective value of rewards).

Study results: We found a stronger preference for immediate over delayed reward in SZ compared to HC, and a larger difference between the perception of near and far future. Compared to HC, MP made more choices that were consistent with their perceived differences between immediate and delayed rewards, which further correlated with lower behavioral activation. In both groups, higher discounting rate correlated with lower choice consistency.

Conclusions: Reward processing dysfunctions may manifest in different ways in different psychotic disorders and may be due to differing underlying mechanisms, which has important implications for targeted intervention development.

Background and hypothesis: Evidence suggests a complex interplay among childhood trauma (CT), substance use, and psychopathology in psychosis, yet the precise nature of these relationships remains unclear. Network analysis offers distinct advantages for examining these factors simultaneously, as it can capture multidirectional associations across multiple trauma subtypes, substances, and symptoms that conventional methods may overlook.

Study design: In this study, data from 317 patients with early psychosis were used. CT was assessed across 5 subtypes (sexual, physical, and emotional abuse; physical and emotional neglect) using a tailored questionnaire completed by case managers. Current use of alcohol, opioids, cocaine, cannabis, and amphetamines was evaluated with the Case Manager Rating Scale for Substance Abuse. Symptoms were measured with the Positive and Negative Syndrome Scale. A mixed graphical model was fitted to estimate conditional associations among CT, substance use, and psychopathology. Further analyses on the network's connectivity were conducted.

Study results: Three distinct patterns of connection emerged, respectively associated with cannabis use, depressive symptoms, and attentional difficulties, linking trauma to psychopathology. Cannabis emerged as a central bridge, linking trauma to both symptom severity and broader substance use.

Conclusions: These findings highlight the nuanced relationships between CT, substance use, and psychopathology. They further suggest that cannabis may serve both as a catalyst for psychopathology and as a gateway to broader substance use among trauma-exposed individuals. Together, these findings may support more comprehensive clinical formulation and informed treatment planning in early intervention settings.

Background and hypothesis: Psychotic symptoms are dynamic, yet traditional assessments often measure them retrospectively, potentially missing meaningful symptom variability. Further, many measures are population-specific, limiting their use across the psychosis continuum. To address these gaps, we developed the Momentary Assessment of Psychotic Experiences (MAPE), a brief self-report questionnaire measuring in-the-moment psychosis across the continuum.

Study design: Validation included cross-sectional administration in two community samples (n = 1948) and one clinical sample with psychotic disorders (n = 73), as well as a repeated-administration design in two control samples (n = 1604). Exploratory and confirmatory factor analyses were conducted in community and control samples, while internal consistency was examined across samples. Convergent validity was tested against the Paranoia Scale, Magical Ideation Scale, Revised Hallucinations Scale, and Revised Social Anhedonia Scale. Concurrent validity in the clinical sample was evaluated using the Scales for the Assessment of Positive Symptoms and Negative Symptoms.

Study results: Analyses identified five factors: unusual thoughts and sensory experiences, paranoia, amotivation/anhedonia, social anhedonia, and negative affect. This structure showed excellent model fit and internal consistency in community/control samples, with comparable reliability in the clinical sample. MAPE subscales demonstrated moderate correlations with subclinical psychosis measures and interviewer-rated symptoms.

Conclusions: Findings support the MAPE as a valid and standardized measure of momentary psychotic experiences. By focusing on current state, the MAPE reduces retrospective bias and improves ecological validity. Designed for use across both subclinical and clinical populations, the MAPE also offers a unique tool for studying psychotic symptoms along the continuum.