Daniel I. Shapiro

Stress and neurodevelopmental processes in the emergence of psychosis

The notion that stress plays a role in the etiology of psychotic disorders, especially schizophrenia, is longstanding. However, it is only in recent years that the potential neural mechanisms mediating this effect have come into sharper focus. The introduction of more sophisticated models of the interplay between psychosocial factors and brain function has expanded our opportunities for conceptualizing more detailed psychobiological models of stress in psychosis. Further, scientific advances in our understanding of adolescent brain development have shed light on a pivotal question that has challenged researchers; namely, why the first episode of psychosis typically occurs in late adolescence/young adulthood. In this paper, we begin by reviewing the evidence supporting associations between psychosocial stress and psychosis in diagnosed patients as well as individuals at clinical high risk for psychosis. We then discuss biological stress systems and examine changes that precede and follow psychosis onset. Next, research findings on structural and functional brain characteristics associated with psychosis are presented; these findings suggest that normal adolescent neuromaturational processes may go awry, thereby setting the stage for the emergence of psychotic syndromes. Finally, a model of neural mechanisms underlying the pathogenesis of psychosis is presented and directions for future research strategies are explored.

Stress and the Prodromal Phase of Psychosis

Stress plays a role in most conceptualizations of the etiology of psychotic disorders. This is based on extensive research showing an association between the incidence of psychosis and psychosocial stress exposure (e.g., stressful life events and trauma) both in childhood and the weeks preceding a psychotic episode. There is also evidence of increased sensitivity to stressful events and dysregulation of biological stress systems. To better understand the relation of stress with the initial emergence of psychosis, research has increasingly focused on the psychosis prodrome, the period of functional decline that precedes clinical illness. Preliminary results suggest that increased incidence of early childhood trauma, heightened sensitivity to psychosocial stress, and dysregulation of biological stress response systems are present in the prodrome and associated with the onset and severity of psychosis. The current paper reviews this research and discusses the possible mechanisms responsible for these associations. This discussion includes the possible effect of stress on the hypothalamic-pituitary-adrenal [HPA] axis and hippocampus, and the role adolescent developmental changes may play in mediating this effect. Further longitudinal research combining clinical and biological measures of stress with techniques designed to assess developmental change in neural structure and function, cellular mechanisms, and genetic and epigenetic factors are critical for elucidating the role stress plays in the pathophysiology of psychotic illness.

Developmental mechanisms in the prodrome to psychosis

Psychotic disorders continue to be among the most disabling and scientifically challenging of all mental illnesses. Accumulating research findings suggest that the etiologic processes underlying the development of these disorders are more complex than had previously been assumed. At the same time, this complexity has revealed a wider range of potential options for preventive intervention, both psychosocial and biological. In part, these opportunities result from our increased understanding of the dynamic and multifaceted nature of the neurodevelopmental mechanisms involved in the disease process, as well as the evidence that many of these entail processes that are malleable. In this article, we review the burgeoning research literature on the prodrome to psychosis, based on studies of individuals who meet clinical high risk criteria. This literature has examined a range of factors, including cognitive, genetic, psychosocial, and neurobiological. We then turn to a discussion of some contemporary models of the etiology of psychosis that emphasize the prodromal period. These models encompass the origins of vulnerability in fetal development, as well as postnatal stress, the immune response, and neuromaturational processes in adolescent brain development that appear to go awry during the prodrome to psychosis. Then, informed by these neurodevelopmental models of etiology, we turn to the application of new research paradigms that will address critical issues in future investigations. It is expected that these studies will play a major role in setting the stage for clinical trials aimed at preventive intervention.

Progress and Future Directions in Research on the Psychosis Prodrome: A Review for Clinicians.

Learning ObjectivesAfter participating in this activity, learners should be better able to:Assess tools and criteria that can reliably identify imminent risk for a psychotic disorderEvaluate longitudinal clinical and psychobiological data that are strengthening individual risk assessmentIdentify interventions that are demonstrating promise for delaying or preventing the onset of psychosis in help-seeking high-risk individuals AbstractThe psychosis prodrome, or period of clinical and functional decline leading up to acute psychosis, offers a unique opportunity for identifying mechanisms of psychosis onset and for testing early-intervention strategies. We summarize major findings and emerging directions in prodromal research and provide recommendations for clinicians working with individuals suspected to be at high risk for psychosis. The past two decades of research have led to three major advances. First, tools and criteria have been developed that can reliably identify imminent risk for a psychotic disorder. Second, longitudinal clinical and psychobiological data from large multisite studies are strengthening individual risk assessment and offering insights into potential mechanisms of illness onset. Third, psychosocial and pharmacological interventions are demonstrating promise for delaying or preventing the onset of psychosis in help-seeking, high-risk individuals. The dynamic psychobiological processes implicated in both risk and onset of psychosis, including altered gene expression, cognitive dysfunction, inflammation, gray and white matter brain changes, and vulnerability-stress interactions suggest a wide range of potential treatment targets and strategies. The expansion of resources devoted to early intervention and prodromal research worldwide raises hope for investigating them. Future directions include identifying psychosis-specific risk and resilience factors in children, adolescents, and non-help-seeking community samples, improving study designs to test hypothesized mechanisms of change, and intervening with strategies that, in order to improve functional outcomes, better engage youth, address their environmental contexts, and focus on evidence-based neurodevelopmental targets. Prospective research on putatively prodromal samples has the potential to substantially reshape our understanding of mental illness and our efforts to combat it.

The Prodrome and Clinical Risk for Psychotic Disorders

The psychosis prodrome offers great promise for identifying neural mechanisms involved in psychotic disorders and offers an opportunity to implement empirical interventions to delay, and ultimately ameliorate, illness onset. This article summarizes the literature on individuals in the putatively prodromal phase of psychosis/deemed at clinical high risk (CHR) for psychosis onset. Standardized measurement and manifestation of the CHR syndromes are discussed, followed by empirical findings that highlight the psychological deficits and biological abnormalities seen in CHR syndromes and psychotic disorders. Current controversies surrounding the diagnosis of CHR syndromes and issues related to the treatment of CHR individuals are also presented.

Neurodevelopment and Schizophrenia: Broadening the Focus

Developmental changes in the brain are now a central feature of most etiological theories of schizophrenia. From the fetal period, in which vulnerability is presumed to originate, to the emergence of clinical illness in adolescence, brain changes are setting the stage for the first episode of psychosis. A host of factors that have the ability to alter fetal brain development have been linked with schizophrenia. Heritable genetic factors may increase risk for aberrant fetal brain development, and molecular genetic studies are now revealing mutations and epigenetic events that can also derail normal developmental processes. Prenatal complications also are now known to be associated with vulnerability. Later, adolescence and early adulthood are the critical periods for the onset of the prodrome, the period of decline before illness onset, and then the clinical syndrome. Here we summarize hypothesized elements of the neurodevelopmental process in schizophrenia in a model that spans both the prenatal and adolescent/young-adult periods. It is likely that future models will be much more complex as epigenetic processes and gene–environment interactions are incorporated.

S105. VALIDATING THE PREDICTIVE ACCURACY OF THE NAPLS-2 PSYCHOSIS RISK CALCULATOR IN A CLINICAL HIGH-RISK SAMPLE FROM THE SHARP (SHANGHAI AT RISK FOR PSYCHOSIS) PROGRAM

Abstract Background The present study aims to validate the predictive accuracy of the NAPLS-2 psychosis risk calculator in a clinical high-risk (CHR) sample from the SHARP (ShangHai At Risk for Psychosis) program in Shanghai, China using comparable inclusion/exclusion criteria and assessments. Methods Three hundred CHR individuals were identified by the Chinese version of the Structured Interview for Prodromal Symptoms. Of these, 228 (76.0%) completed neuro-cognitive assessments at baseline and 199 (66.3%) had at least a one-year follow-up assessment. The latter group was used in risk calculation. Six key predictors (baseline age, unusual thoughts and suspiciousness, symbol coding and verbal learning test performance, functional decline and family history of psychosis) were entered into the NAPLS-2 model to generate a psychosis risk estimate for each case. The area under the receiver operating characteristic curve (AUC) was used to test the effectiveness of this discrimination. Results The NAPLS risk calculator showed moderate discrimination of subsequent transition to psychosis in the SHARP sample with an AUC of 0.631 (p = 0.007). Whether discriminating either transition or poor treatment/clinical outcomes, the AUC of the model increased to 0.754 (p < 0.001). A risk estimate of 30% or higher had moderate sensitivity (53%) and excellent specificity (86%) for prediction of poor treatment/clinical outcome. Discussion The NAPLS-2 risk calculator largely generalizes to a Shanghai CHR sample but is meaningfully improved when predicting an individual’s poor clinical outcome as well as conversion. Our findings provide a critical step in the implementation of CHR risk calculation in China.

O2.8. TRAJECTORIES OF NEUROCOGNITIVE FUNCTIONING OVER TIME IN YOUTH AT CLINICAL HIGH RISK WHO DO AND DO NOT TRANSITION TO PSYCHOSIS

Abstract Background In spite of evidence for the premorbid and prodromal onset of cognitive deficits in schizophrenia and related psychotic disorders, there is some limited evidence to suggest that deficits may progress with psychosis onset. Cognitive remediation in youth at risk for psychosis is being touted as an opportunity not only to remediate deficits but to potentially prevent this progression. Yet trajectories of cognitive functioning over time remain poorly understood in youth at risk, including the degree to which age at assessment or illness onset, sociodemographic factors, or symptom progression influence these trajectories. Methods The North American Prodrome Longitudinal Study (NAPLS) -2 collected data on an extensive battery of neuropsychological (NP) tests at baseline, one year, two years, and post-conversion in a sample of clinical high risk (CHR) youth and healthy comparison (HC) subjects ages 12–35 (N= 960, 92% of the full sample) followed clinically for up to 2 years. NP data were available for 694 at CHR and 265 HC. Linear mixed effects analyses were used to test the effects of group, age, gender, age of onset, maternal education, and clinical outcome on cognitive trajectories. Results Those who transitioned to a psychotic disorder over the course of follow-up performed significantly below those who did not and well below healthy comparisons. Tasks reliant on attention, visual and auditory working memory, visuospatial and verbal memory, and processing speed best differentiated those who transitioned from those who did not at one year (Cohen’s d from -0.33 to -0.54). Discrepancies from normal functioning on these tests were generally large (Cohen’s d from -0.67 to -1.02) consistent with findings for first episode samples. Although clinical outcome was not associated with a significantly different trajectory over time on any cognitive domain, these are likely due to high rates of conversion in this sample within the first year. Predictors of different trajectories will be presented. Discussion These data from one of the largest CHR studies to date suggest that much of the neuropsychological dysfunction in major psychotic disorders is present early in the course of illness and prior to its full expression. However, trajectories are highly heterogeneous. More frequent assessment prior to and during the onset of illness are needed to fully understand the cognitive correlates of psychosis onset and the implications for early intervention.