Introduction to Psychotic-Like Experiences and Brain Function

Adolescence represents a critical window of neurodevelopmental vulnerability where many individuals encounter subclinical symptoms known as psychotic-like experiences (PLEs). These experiences, which include perceptual distortions and delusional ideation, are surprisingly common in the general population but do not always lead to a clinical diagnosis. However, research into psychotic-like experiences brain connectivity suggests that certain developmental paths may indicate a higher risk for future psychiatric disorders. Understanding the underlying neural architecture of these experiences is essential for early identification and intervention. Recent advancements in neuroimaging have allowed scientists to examine the resting-state functional connectivity of major brain networks in youth. Specifically, studies focus on how the communication between brain regions changes over time during this formative period. By identifying specific neural signatures, clinicians can better differentiate between transient adolescent experiences and more concerning pathological trajectories. This research offers a unique perspective on the biological foundations of social and emotional processing deficits often seen in early psychosis.

The Dual Roles of the Default-Mode and Salience Networks

Two primary large-scale brain networks are consistently implicated in the pathophysiology of psychosis: the Default-Mode Network (DMN) and the Salience Network (SN). The DMN is primarily associated with socio-cognitive processing, including self-referential thought, mentalizing, and episodic memory. Conversely, the SN plays a pivotal role in socio-affective processing by detecting and filtering salient external and internal stimuli. In a healthy brain, these two networks maintain a coordinated balance to ensure appropriate responses to the environment. However, disturbances in the resting-state functional connectivity between these networks are a hallmark of schizophrenia and clinical high-risk states. Consequently, investigators are now focusing on how psychotic-like experiences brain connectivity manifests in these systems during adolescence. The interaction between the DMN and SN is vital for integrating social information with emotional value. When this interaction is disrupted, individuals may experience difficulties in distinguishing relevant social cues from background noise, leading to the misinterpretations characteristic of PLEs. Thus, the integrity of these networks serves as a critical biomarker for neurodevelopmental health.

Analyzing Longitudinal Trajectories of PLEs in Youth

While many adolescents experience PLEs that naturally resolve over time, a subset follows an atypical trajectory where these symptoms increase in frequency or severity. The current study followed a unique sample of 92 youth over a four-year period to map these developmental pathways. By categorizing participants into typically developing low-PLE groups and atypical increasing-PLE groups, researchers could isolate the neural changes unique to the latter. Longitudinal data is particularly valuable because it captures the dynamic nature of psychotic-like experiences brain connectivity during the teenage years. Most prior studies have relied on cross-sectional data, which provides only a snapshot of a moving target. In this longitudinal cohort, the atypical group displayed distinct patterns of dysconnectivity that emerged alongside their worsening symptoms. Furthermore, these patterns were not present in peers who experienced stable or declining levels of PLEs. This finding underscores the importance of monitoring how brain networks evolve rather than simply measuring them once. It suggests that the "increasing" trajectory carries a specific biological signature that closely mirrors the early stages of psychotic disorders.

Specific Neural Markers: Insula and Amygdala Dysconnectivity

The core findings of the study highlighted significant alterations involving the insula and the amygdala, two regions central to the Salience Network. Adolescents in the atypical PLE trajectory demonstrated reduced connectivity between the SN and the DMN compared to their typically developing peers. Additionally, there was a notable increase in connectivity between the left and right insula, alongside widespread dysconnectivity from the insula and amygdala to other cortical regions. These specific changes in psychotic-like experiences brain connectivity are highly reminiscent of the neural deficits reported in patients with established schizophrenia. The insula acts as a hub for interoceptive awareness and emotional processing, while the amygdala is critical for threat detection. When these regions fail to communicate effectively with the DMN, the internal representation of social and emotional states becomes fragmented. Moreover, the increased inter-hemispheric insular connectivity might represent a compensatory mechanism or a pathological synchronization that further disrupts normal cognitive flow. These findings provide concrete neuroanatomical targets for understanding the sensory and emotional disturbances reported by youth at high risk for psychosis.

Bridging the Gap: From Subclinical PLEs to Clinical Risk

One of the most significant implications of this research is the similarity between subclinical PLE trajectories and clinical high-risk samples. For many years, subclinical symptoms were viewed as separate from psychiatric illness. However, the discovery of shared neural signatures in psychotic-like experiences brain connectivity suggests a continuum of risk. These findings support the "triple network" model of psychopathology, where aberrant coupling between the DMN, SN, and Central Executive Network (CEN) leads to the emergence of psychotic symptoms. By identifying these patterns in adolescents before they reach a clinical threshold, we can potentially map the early developmental stages of psychotic disorders. Furthermore, these neural alterations were observed in youth presenting with atypical PLE trajectories, reinforcing the idea that symptom progression is tied to measurable biological changes. This bridge between subclinical phenomena and clinical pathology is vital for modern psychiatry. It shifts the focus from reactive treatment to proactive monitoring of neurodevelopmental milestones. Ultimately, this approach could help clinicians identify which youth require closer supervision or early psychological support.

Clinical Utility and Early Detection Strategies

For medical professionals in India and globally, these findings emphasize the potential of neuroimaging as a tool for early detection. While expensive, identifying markers in psychotic-like experiences brain connectivity could eventually lead to more accessible screening protocols. Early detection is especially relevant in psychiatry, where the duration of untreated psychosis is a major predictor of long-term outcomes. Furthermore, understanding that insula and amygdala dysconnectivity underlies these symptoms can guide more targeted therapeutic approaches. For instance, social cognition training or mindfulness-based interventions might help re-normalize network interactions during the critical adolescent period. Moreover, these findings highlight the need for longitudinal mental health assessments in pediatric practice. By tracking the trajectory of PLEs over several years, clinicians can identify those on an atypical path and intervene earlier. As our understanding of brain networks grows, the goal is to translate these complex neuroimaging findings into practical clinical insights. This transition will require continued research into how environmental factors and genetics interact with these neural networks to influence psychiatric outcomes in youth.

Frequently Asked Questions

What are the primary brain networks involved in adolescent psychotic-like experiences?

The two main networks involved are the default-mode network (DMN) and the salience network (SN). The DMN handles self-referential thought and social cognition, while the SN manages emotional processing and stimulus detection. Alterations in how these networks communicate are key indicators of increased risk for developing psychotic disorders later in life.

How does connectivity between the insula and amygdala impact mental health?

The insula and amygdala are critical for processing emotions and detecting social salience. Dysconnectivity in these regions can disrupt an individual's ability to interpret social cues and manage internal emotional states. In adolescents with increasing psychotic-like experiences, these connectivity alterations often mirror the neural patterns found in individuals with schizophrenia.

Why is it important to track psychotic-like experiences longitudinally?

Many adolescents experience transient psychotic-like symptoms that resolve naturally. However, those whose symptoms increase over time show specific brain connectivity changes. Tracking these experiences longitudinally allows clinicians to distinguish between typical developmental fluctuations and atypical trajectories that may require early intervention to prevent the onset of clinical psychiatric disorders.

Disclaimer: This content is for informational and educational purposes only. It is not intended as medical advice or to replace a consultation with a qualified healthcare professional. Clinical decisions should be based on an individual patient's history and symptoms. Refer to the latest local and national guidelines for clinical practice.

References

Assaf R et al. Resting-state alterations in emotion salience and default-mode network connectivity in atypical trajectories of psychotic-like experiences. Dev Psychopathol. 2025 Aug. doi: 10.1017/S0954579424001317. PMID: 39297232.

Uddin LQ. Salience Network of the Human Brain. Cambridge University Press; 2017.

Kelleher I, et al. Psychotic experiences in the general population: a review of definition, risk factors, and implications. Psychological Medicine. 2012.