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Dissertation
Thalamocortical connectivity in children with distressful sub-clinical psychotic experiences
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Summer 2025
DOI: 10.25820/etd.008166
Abstract
Transient subclinical perceptual events and odd thinking known as psychotic-like experiences (PLEs) can commonly manifest in children. In rare instances when PLEs are persistent or distressful, they may indicate high risk for later psychotic illness, such as schizophrenia. Numerous neurobiological and environmental models propose explanations of PLEs, clinical high risk, and psychosis, but causal mechanisms remain unclear. Resting-state functional connectivity (FC) imaging studies have consistently exhibited a pattern of increased positive thalamic connectivity to sensorimotor cortex and reduced connectivity to the prefrontal cortex in people living with chronic schizophrenia, first-episode patients, first-degree relatives of patients, and those at high clinical risk, suggesting thalamocortical connectivity (TCC) represents a neurobiological marker of schizophrenia. However, our knowledge of TCC in children with subclinical psychotic events is limited, thus motivating the current investigation in nine- and ten-year-old youth with PLEs in the Adolescent Brain Cognitive Development (ABCD) dataset by investigating TCC differences in children with and without distressing PLEs, exploring if TCC abnormalities are specific to thalamic nuclei, and to assess whether baseline TCC influences PLE trajectory. Using baseline magnetic resonance imaging (MRI) scans and clinical assessments collected two years apart in 671 participants, we applied linear and logistic mixed-effects models and identified three key findings:1. Children with highly distressing PLEs showed reduced negative thalamic connectivity with prefrontal cortex and occipital pole regions (Default Mode and Visual networks), driven primarily by the ventral thalamus.
2. High PLEs were also associated with increased positive thalamic connectivity to the right frontal operculum, suggesting an overactive or inefficient salience network.
3. Baseline thalamic connectivity with the middle and inferior frontal gyri (frontoparietal network) predicted persistent versus resolving PLE trajectories after two years among children with High PLEs at baseline.
These findings should be interpreted cautiously, as typical neurodevelopmental patterns of thalamocortical connectivity (TCC) and the broader impact of mental health difficulties may influence the manifestation of PLE-related TCC differences. Further analyses into later longitudinal follow-ups of PLE and TCC trajectories could help elucidate how these changes further relate to these variables. These findings highlight the importance of early neural differentiation in PLE trajectories and may inform future risk stratification approaches.
Details
- Title: Subtitle
- Thalamocortical connectivity in children with distressful sub-clinical psychotic experiences
- Creators
- Amy Barry
- Contributors
- Bengi Baran (Advisor)Peg Nopoulos (Advisor)Vince Magnotta (Committee Member)Timothy Koscik (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Neuroscience
- Date degree season
- Summer 2025
- DOI
- 10.25820/etd.008166
- Publisher
- University of Iowa
- Number of pages
- x, 96 pages
- Copyright
- Copyright 2025 Amy Barry
- Language
- English
- Date submitted
- 07/29/2025
- Description illustrations
- illustrations (some color)
- Description bibliographic
- Includes bibliographical references (pages 76-90).
- Public Abstract (ETD)
Children sometimes report unusual thoughts or perceptions, like hearing sounds that aren t there or feeling watched. These experiences, known as psychotic-like experiences (PLEs), are often harmless and brief. However, when they are frequent or distressing, they may signal a higher risk for mental health conditions such as schizophrenia later in life.
While biological and environmental factors have been linked to PLEs, the brain mechanisms underlying these experiences are not well understood. One promising area of study, called functional connectivity, examines how different brain regions communicate with one another. Previous research has shown that individuals with, or at high risk for, schizophrenia often have abnormal connections between the thalamus, a critical relay hub, and other brain areas. Little is known about these patterns in children with PLEs.
In this study, we analyzed brain scans and mental health data from 671 nine- and ten-year-olds in the Adolescent Brain Cognitive Development (ABCD) Study to investigate how thalamic connectivity relates to current and future PLEs.
We found that:
1. Children with frequent and distressing PLEs had disrupted communication between the thalamus and brain regions involved in decision-making and vision.
2. These children also showed unusually strong connections between the thalamus and areas that filter important information, suggesting inefficiency in this network.
3. Thalamic connectivity with brain regions supporting planning and problem-solving predicted whether PLEs persisted or improved over two years.
These findings suggest that thalamic connectivity patterns may help identify children at risk for later mental illness and guide early interventions.
- Academic Unit
- Interdisciplinary Graduate Program in Neuroscience
- Record Identifier
- 9984948640702771
Metrics
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