Pituitary volume in individuals at elevated risk for psychosis: A systematic review and meta-analysis

Investigating the Impacts of Diet, Supplementation, Microbiota, Gut-Brain Axis on Schizophrenia: A Narrative Review

Schizophrenia is a disease with a complex etiology that significantly impairs the functioning of patients. In recent years, there has been increasing focus on the importance of the gut microbiota in the context of the gut-brain axis. In our study, we analyzed data on the gut-brain axis in relation to schizophrenia, as well as the impacts of eating habits, the use of various supplements, and diets on schizophrenia. Additionally, the study investigated the impact of antipsychotics on the development of metabolic disorders, such as diabetes, dyslipidemia, and obesity. There may be significant clinical benefits to be gained from therapies supported by supplements such as omega-3 fatty acids, B vitamins, and probiotics. The results suggest the need for a holistic approach to the treatment of schizophrenia, incorporating both drug therapy and dietary interventions.

Enlarged pituitary gland volume: a possible state rather than trait marker of psychotic disorders

BACKGROUND

Enlarged pituitary gland volume could be a marker of psychotic disorders. However, previous studies report conflicting results. To better understand the role of the pituitary gland in psychosis, we examined a large transdiagnostic sample of individuals with psychotic disorders.

METHODS

The study included 751 participants (174 with schizophrenia, 114 with schizoaffective disorder, 167 with psychotic bipolar disorder, and 296 healthy controls) across six sites in the Bipolar-Schizophrenia Network on Intermediate Phenotypes consortium. Structural magnetic resonance images were obtained, and pituitary gland volumes were measured using the MAGeT brain algorithm. Linear mixed models examined between-group differences with controls and among patient subgroups based on diagnosis, as well as how pituitary volumes were associated with symptom severity, cognitive function, antipsychotic dose, and illness duration.

RESULTS

Mean pituitary gland volume did not significantly differ between patients and controls. No significant effect of diagnosis was observed. Larger pituitary gland volume was associated with greater symptom severity (F = 13.61, p = 0.0002), lower cognitive function (F = 4.76, p = 0.03), and higher antipsychotic dose (F = 5.20, p = 0.02). Illness duration was not significantly associated with pituitary gland volume. When all variables were considered, only symptom severity significantly predicted pituitary gland volume (F = 7.54, p = 0.006).

CONCLUSIONS

Although pituitary volumes were not increased in psychotic disorders, larger size may be a marker associated with more severe symptoms in the progression of psychosis. This finding helps clarify previous inconsistent reports and highlights the need for further research into pituitary gland-related factors in individuals with psychosis.

Stress, Environment and Early Psychosis

Existing literature provides extended evidence of the close relationship between stress dysregulation, environmental insults, and psychosis onset. Early stress can sensitize genetically vulnerable individuals to future stress, modifying their risk for developing psychotic phenomena. Neurobiological substrate of the aberrant stress response to hypothalamic-pituitary-adrenal axis dysregulation, disrupted inflammation processes, oxidative stress increase, gut dysbiosis, and altered brain signaling, provides mechanistic links between environmental risk factors and the development of psychotic symptoms. Early-life and later-life exposures may act directly, accumulatively, and repeatedly during critical neurodevelopmental time windows. Environmental hazards, such as pre- and perinatal complications, traumatic experiences, psychosocial stressors, and cannabis use might negatively intervene with brain developmental trajectories and disturb the balance of important stress systems, which act together with recent life events to push the individual over the threshold for the manifestation of psychosis. The current review presents the dynamic and complex relationship between stress, environment, and psychosis onset, attempting to provide an insight into potentially modifiable factors, enhancing resilience and possibly influencing individual psychosis liability.

The Translational Future of Stress Neurobiology and Psychosis Vulnerability: A Review of the Evidence

Psychosocial stress is a well-established risk factor for psychosis, yet the neurobiological mechanisms underlying this relationship have yet to be fully elucidated. Much of the research in this field has investigated hypothalamic-pituitary-adrenal (HPA) axis function and immuno-inflammatory processes among individuals with established psychotic disorders. However, as such studies are limited in their ability to provide knowledge that can be used to develop preventative interventions, it is important to shift the focus to individuals with increased vulnerability for psychosis (i.e., high-risk groups). In the present article, we provide an overview of the current methods for identifying individuals at high-risk for psychosis and review the psychosocial stressors that have been most consistently associated with psychosis risk. We then describe a network of interacting physiological systems that are hypothesised to mediate the relationship between psychosocial stress and the manifestation of psychotic illness and critically review evidence that abnormalities within these systems characterise highrisk populations. We found that studies of high-risk groups have yielded highly variable findings, likely due to (i) the heterogeneity both within and across high-risk samples, (ii) the diversity of psychosocial stressors implicated in psychosis, and (iii) that most studies examine single markers of isolated neurobiological systems. We propose that to move the field forward, we require well-designed, largescale translational studies that integrate multi-domain, putative stress-related biomarkers to determine their prognostic value in high-risk samples. We advocate that such investigations are highly warranted, given that psychosocial stress is undoubtedly a relevant risk factor for psychotic disorders.

A Review of Potential Neuroimaging Biomarkers of Schizophrenia-Risk

The risk for developing schizophrenia is increased among first-degree relatives of those with psychotic disorders, but the risk is even higher in those meeting established criteria for clinical high risk (CHR), a clinical construct most often comprising of attenuated psychotic experiences. Conversion to psychosis among CHR youth has been reported to be about 15-35% over three years. Accurately identifying individuals whose psychotic symptoms will worsen would facilitate earlier intervention, but this has been difficult to do using behavior measures alone. Brain-based risk markers have the potential to improve the accuracy of predicting outcomes in CHR youth. This narrative review provides an overview of neuroimaging studies used to investigate psychosis risk, including studies involving structural, functional, and diffusion imaging, functional connectivity, positron emission tomography, arterial spin labeling, magnetic resonance spectroscopy, and multi-modality approaches. We present findings separately in those observed in the CHR state and those associated with psychosis progression or resilience. Finally, we discuss future research directions that could improve clinical care for those at high risk for developing psychotic disorders.

The Critical Roles of Early Development, Stress, and Environment in the Course of Psychosis

Psychotic disorders are highly debilitating with poor prognoses and courses of chronic illness. In recent decades, conceptual models have shaped understanding, informed treatment, and guided research questions. However, these models have classically focused on the adolescent and early adulthood stages immediately preceding onset while conceptualizing early infancy through all of childhood as a unitary premorbid period. In addition, models have paid limited attention to differential effects of types of stress; contextual factors such as local, regional, and country-level characteristics or sociocultural contexts; and the timing of the stressor or environmental risk. This review discusses emerging research suggesting that (a) considering effects specific to neurodevelopmental stages prior to adolescence is highly informative, (b) understanding specific stressors and levels of environmental exposures (i.e., systemic or contextual features) is necessary, and (c) exploring the dynamic interplay between development, levels and types of stressors, and environments can shed new light, informing a specified neurodevelopmental and multifaceted diathesis-stress model.

Electroconvulsive Therapy in Psychiatric Disorders: A Narrative Review Exploring Neuroendocrine–Immune Therapeutic Mechanisms and Clinical Implications

Electroconvulsive therapy (ECT) is based on conducting an electrical current through the brain to stimulate it and trigger generalized convulsion activity with therapeutic ends. Due to the efficient use of ECT during the last years, interest in the molecular bases involved in its mechanism of action has increased. Therefore, different hypotheses have emerged. In this context, the goal of this review is to describe the neurobiological, endocrine, and immune mechanisms involved in ECT and to detail its clinical efficacy in different psychiatric pathologies. This is a narrative review in which an extensive literature search was performed on the Scopus, Embase, PubMed, ISI Web of Science, and Google Scholar databases from inception to February 2022. The terms “electroconvulsive therapy”, “neurobiological effects of electroconvulsive therapy”, “molecular mechanisms in electroconvulsive therapy”, and “psychiatric disorders” were among the keywords used in the search. The mechanisms of action of ECT include neurobiological function modifications and endocrine and immune changes that take place after ECT. Among these, the decrease in neural network hyperconnectivity, neuroinflammation reduction, neurogenesis promotion, modulation of different monoaminergic systems, and hypothalamus–hypophysis–adrenal and hypothalamus–hypophysis–thyroid axes normalization have been described. The majority of these elements are physiopathological components and therapeutic targets in different mental illnesses. Likewise, the use of ECT has recently expanded, with evidence of its use for other pathologies, such as Parkinson’s disease psychosis, malignant neuroleptic syndrome, post-traumatic stress disorder, and obsessive–compulsive disorder. In conclusion, there is sufficient evidence to support the efficacy of ECT in the treatment of different psychiatric disorders, potentially through immune, endocrine, and neurobiological systems.

Cortisol Levels in Childhood Associated With Emergence of Attenuated Psychotic Symptoms in Early Adulthood

BACKGROUND

In individuals at clinical high-risk for psychosis, elevated cortisol levels predict subsequent onset of psychotic disorder. However, it is unclear whether cortisol alterations are evident at an earlier clinical stage and promote progression of psychosis expression. This study aimed to address this issue by investigating whether cortisol levels in childhood were associated with the emergence of attenuated psychotic symptoms in early adulthood. In exploratory analyses, we examined whether cortisol and psychosocial stress measures interacted in predicting attenuated psychotic symptoms.

METHODS

A sample of children (N = 109) enriched for psychosis risk factors were recruited at age 9-12 years and assessed at age 11-14 years (T1) and 17-21 years (T2). Measures of psychopathology, psychosocial stressors, and salivary cortisol were obtained at T1. Attenuated psychotic symptoms were assessed at T2 using the Prodromal Questionnaire.

RESULTS

Diurnal cortisol (β = 0.915, 95% CI: 0.062-1.769) and daily stressors (β = 0.379, 95% CI: 0.034-0.723) at T1 were independently associated with total Prodromal Questionnaire scores at T2 after accounting for demographic factors and T1 psychopathology. Exploratory analyses indicated a significant interaction between T1 diurnal cortisol and daily stressors (β = 0.743, 95% CI: 0.081-1.405), with the highest predicted T2 total Prodromal Questionnaire scores occurring when both diurnal cortisol and daily stressors were increased.

CONCLUSIONS

Our findings suggest that daily stressors and elevations in diurnal cortisol in late childhood/early adolescence increases risk for developing attenuated psychotic symptoms. These findings emphasize the importance of assessing environmental and biological risk factors for psychosis during neurodevelopmentally vulnerable time periods.

Childhood Trauma, the HPA Axis and Psychiatric Illnesses: A Targeted Literature Synthesis

Studies of early life stress (ELS) demonstrate the long-lasting effects of acute and chronic stress on developmental trajectories. Such experiences can become biologically consolidated, creating individual vulnerability to psychological and psychiatric issues later in life. The hippocampus, amygdala, and the medial prefrontal cortex are all important limbic structures involved in the processes that undermine mental health. Hyperarousal of the sympathetic nervous system with sustained allostatic load along the Hypothalamic Pituitary Adrenal (HPA) axis and its connections has been theorized as the basis for adult psychopathology following early childhood trauma. In this review we synthesize current understandings and hypotheses concerning the neurobiological link between childhood trauma, the HPA axis, and adult psychiatric illness. We examine the mechanisms at play in the brain of the developing child and discuss how adverse environmental stimuli may become biologically incorporated into the structure and function of the adult brain via a discussion of the neurosequential model of development, sensitive periods and plasticity. The HPA connections and brain areas implicated in ELS and psychopathology are also explored. In a targeted review of HPA activation in mood and psychotic disorders, cortisol is generally elevated across mood and psychotic disorders. However, in bipolar disorder and psychosis patients with previous early life stress, blunted cortisol responses are found to awakening, psychological stressors and physiological manipulation compared to patients without previous early life stress. These attenuated responses occur in bipolar and psychosis patients on a background of increased cortisol turnover. Although cortisol measures are generally raised in depression, the evidence for a different HPA activation profile in those with early life stress is inconclusive. Further research is needed to explore the stress responses commonalities between bipolar disorder and psychosis in those patients with early life stress.

Neuroimaging Markers of Resiliency in Youth at Clinical High Risk for Psychosis: A Qualitative Review

Psychotic disorders are highly debilitating and constitute a major public health burden. Identifying markers of psychosis risk and resilience is a necessary step toward understanding etiology and informing prevention and treatment efforts in individuals at clinical high risk (CHR) for psychosis. In this context, it is important to consider that neural risk markers have been particularly useful in identifying mechanistic determinants along with predicting clinical outcomes. Notably, despite a growing body of supportive literature and the promise of recent findings identifying potential neural markers, the current work on CHR resilience markers has received little attention. The present review provides a brief overview of brain-based risk markers with a focus on predicting symptom course. Next, the review turns to protective markers, examining research from nonpsychiatric and schizophrenia fields to build an understanding of framing, priorities, and potential, applying these ideas to contextualizing a small but informative body of resiliency-relevant CHR research. Four domains (neurocognition, emotion regulation, allostatic load, and sensory and sensorimotor function) were identified and are discussed in terms of behavioral and neural markers. Taken together, the literature suggests significant predictive value for brain-based markers for individuals at CHR for psychosis, and the limited but compelling resiliency work highlights the critical importance of expanding this promising area of inquiry.

Associations between early life stress and anterior pituitary gland volume development during late childhood

Early Life Stress (ELS) is thought to influence Hypothalamic-Pituitary-Adrenal-Axis (HPAA) functioning, contributing to an increased risk for psychopathology through dysregulation of biological stress responses. Research exploring relationships between ELS and HPAA functioning has largely focused on its key hormonal output, cortisol. However, findings have been inconsistent, potentially due to cortisol's distinctive diurnal patterns and dynamic nature complicating its accurate measurement. Thus, this study explored the link between ELS and a more stable, structural component of the HPAA, specifically, anterior pituitary gland volume (PGV) in a community sample of children (N = 129, 68 female). PGV was traced from Magnetic Resonance Imaging brain scans across two time-points at ages 8 (baseline) and 10 years (follow-up). ELS exposure was assessed at baseline through parent-report questionnaires and maternal affective behavior observed in mother-child interaction tasks. ELS variables were reduced to a 5-factor structure using exploratory factor analysis - Uninvolved Parenting, Negative Affective Parenting, Neglect, Trauma, and Dysfunctional Discipline. Direct and sex-moderated associations between ELS and PGV were explored using regression and linear mixed models analyses. PGV-mediated associations between ELS and internalizing symptoms were also investigated. Childhood Neglect was significantly associated with greater baseline anterior PGV, that was stable over the follow-up period. This effect was found in the whole sample, and in males, specifically. No mediation effects were found. Results suggest that neglect may play a unique role in HPAA neurodevelopment; however, it is important that future research extends into adolescence to more clearly characterize these neurodevelopmental associations and any subsequent psychopathological outcomes.

Associations between early life stress and anterior pituitary gland volume development - A novel index of long-term hypothalamic-pituitary-adrenal axis functioning

Previous research has established associations between early life stress (ELS) and altered pituitary gland volume (PGV) growth during adolescence. The pituitary gland, however, is composed of an anterior and a posterior lobe with distinct histological and neuroendocrinological properties. While the anterior (but not posterior) pituitary gland is directly involved in the hypothalamic-pituitary-adrenal axis (HPAA) stress response, no studies have examined the effects of ELS on anterior PGV (aPGV). The present study investigated whether previously reported associations between ELS and PGV development during adolescence were driven by aPGV versus posterior PGV (pPGV). Ninety-one adolescents (49 males) were included from a longitudinal, community-based adolescent development study investigating risk for psychopathology. ELS (maternal affective behavior, childhood maltreatment, stressful life events) was assessed during early adolescence. Participants underwent two waves of structural magnetic resonance imaging during mid- and late-adolescence, and aPGV and pPGV were manually traced. Regression analyses showed that childhood maltreatment predicted greater aPGV growth in females. This finding was stronger than that previously reported for PGV. No associations were found between ELS and pPGV development. Neither aPGV nor pPGV changes mediated associations between ELS and psychopathology. Results suggest that ELS may accelerate aPGV (but not pPGV) growth throughout adolescence. Investigating the development of aPGV, rather than PGV, represents a novel approach to studying the effects of stress on HPAA functioning.

Are adult stressful life events associated with psychotic relapse? A systematic review of 23 studies

Relapse rates among individuals with psychotic disorders are high. In addition to the financial burden placed on clinical services, relapse is associated with worse long-term prognosis and poorer quality of life. Robust evidence indicates that stressful life events commonly precede the onset of the first psychotic episode; however, the extent to which they are associated with relapse remains unclear. The aim of this systematic review is to summarize available research investigating the association between recent stressful life events and psychotic relapse or relapse of bipolar disorder if the diagnosis included psychotic symptoms. PsycINFO, Medline and EMBASE were searched for cross-sectional, retrospective and prospective studies published between 01/01/1970 and 08/01/2020 that investigated the association between adult stressful life events and relapse of psychosis. Study quality was assessed using the Effective Public Health Practice Project guidelines. Twenty-three studies met eligibility criteria (prospective studies: 14; retrospective studies: 6; cross-sectional: 3) providing data on 2046 participants in total (sample size range: 14-240 participants). Relapse was defined as a return of psychotic symptoms (n = 20), a return of symptoms requiring hospitalization (n = 2) and a return of symptoms or hospitalization (n = 1). Adult stressful life events were defined as life events occurring after the onset of psychosis. Stressful life events included but were not limited to adult trauma, bereavement, financial problems and conflict. Eighteen studies found a significant positive association between adult stressful life events and psychotic relapse and five studies found a non-significant association. We conclude that adult stressful life events, occurring after psychosis onset, appear to be associated with psychotic relapse.

Impaired hormonal regulation of appetite in schizophrenia: A narrative review dissecting intrinsic mechanisms and the effects of antipsychotics

Cardiometabolic diseases are the main contributor of reduced life expectancy in patients with schizophrenia. It is now widely accepted that antipsychotic treatment plays an important role in the development of obesity and its consequences. However, some intrinsic mechanisms need to be taken into consideration. One of these mechanisms might be related to impaired hormonal regulation of appetite in this group of patients. In this narrative review, we aimed to dissect impairments of appetite-regulating hormones attributable to intrinsic mechanisms and those related to medication effects. Early hormonal alterations that might be associated with intrinsic mechanisms include low levels of leptin and glucagon-like peptide-1 (GLP-1) together with elevated insulin levels in first-episode psychosis (FEP) patients. However, evidence regarding low GLP-1 levels in FEP patients is based on one large study. In turn, multiple-episode schizophrenia patients show elevated levels of insulin, leptin and orexin A together with decreased levels of adiponectin. In addition, patients receiving olanzapine may present with low ghrelin levels. Post mortem studies have also demonstrated reduced number of neuropeptide Y neurons in the prefrontal cortex of patients with schizophrenia. Treatment with certain second-generation antipsychotics may also point to these alterations. Although our understanding of hormonal regulation of appetite in schizophrenia has largely been improved, several limitations and directions for future studies need to be addressed. This is of particular importance since several novel pharmacological interventions for obesity and diabetes have already been developed and translation of these developments to the treatment of cardiometabolic comorbidities in schizophrenia patients is needed.

The relevance of chronic stress for the acute stress reaction in people at elevated risk for psychosis

BACKGROUND

Theoretical models and empirical evidence suggest that alterations of the acute stress reaction are a vulnerability indicator of psychosis. However, more studies are needed that use laboratory stressors and a multimodal assessment of the stress reaction. Furthermore, it needs to be clarified whether alterations of the acute stress reaction result from the chronic stress level.

METHODS

We recruited participants at familial (n = 32) and symptomatic risk (n = 43) for psychosis and a low-risk control group (n = 35). We assessed their chronic stress levels (self-report, hair cortisol concentrations) and self-reported (subjective, affective, paranoia) as well as physiological (heart rate, skin conductance level, cortisol) reactions to the Trier Social Stress Test.

RESULTS

The groups did not differ in their acute stress reaction but both at-risk groups showed higher levels of self-reported chronic stress. Chronic stress predicted changes in negative affect, paranoia and skin conductance level in the total sample.

CONCLUSIONS

We could not confirm that alterations of the acute stress reaction are an early vulnerability indicator of psychosis and conclude that they might develop at a later time-point on the trajectory to psychosis. The high chronic stress level of the at-risk groups might constitute an intermediate state that increases the likelihood of altered stress reactions in later risk stages. To test this, future work needs to investigate the temporal order between chronic stress levels, acute stress reactions and symptom development across the psychosis continuum.

The HPA axis dysregulation in severe mental illness: Can we shift the blame to gut microbiota?

Accumulating evidence indicates that patients with severe mental disorders, including major depression, bipolar disorder and schizophrenia present with various alterations of the gut microbiota and increased intestinal permeability. In addition, the hypothalamic-pituitary-adrenal (HPA) axis dysregulation and subclinical inflammation have been reported in this group of patients. Although it has been found that the HPA axis dysregulation appears as a consequence of psychosocial stress, especially traumatic life events, the exact mechanisms of this observation remain unclear. Animal model studies have unraveled several mechanisms linking the gut microbiota with the HPA axis dysfunction. Indeed, the gut microbiota can activate the HPA axis through several mediators that cross the blood-brain barrier and include microbial antigens, cytokines and prostaglandins. There is also evidence that various microbial species can affect ileal corticosterone production that may impact the activity of the HPA axis. However, some metabolites released by various microbes, e.g., short-chain fatty acids, can attenuate the HPA axis response. Moreover, several bacteria release neurotransmitters that can directly interact with vagal afferents. It has been postulated that the HPA axis activation can impact the gut microbiota and intestinal permeability. In this article, we discuss various mechanisms linking the gut microbiota with the HPA axis activity and summarize current evidence for a cross-talk between the gut-brain axis and the HPA axis from studies of patients with mood and psychotic disorders. Finally, we show potential clinical implications that can arise from future studies investigating the HPA axis activity with respect to the gut microbiota in severe mental disorders.

Prevention of Psychosis: Advances in Detection, Prognosis, and Intervention

IMPORTANCE

Detection, prognosis, and indicated interventions in individuals at clinical high risk for psychosis (CHR-P) are key components of preventive psychiatry.

OBJECTIVE

To provide a comprehensive, evidence-based systematic appraisal of the advancements and limitations of detection, prognosis, and interventions for CHR-P individuals and to formulate updated recommendations.

EVIDENCE REVIEW

Web of Science, Cochrane Central Register of Reviews, and Ovid/PsychINFO were searched for articles published from January 1, 2013, to June 30, 2019, to identify meta-analyses conducted in CHR-P individuals. MEDLINE was used to search the reference lists of retrieved articles. Data obtained from each article included first author, year of publication, topic investigated, type of publication, study design and number, sample size of CHR-P population and comparison group, type of comparison group, age and sex of CHR-P individuals, type of prognostic assessment, interventions, quality assessment (using AMSTAR [Assessing the Methodological Quality of Systematic Reviews]), and key findings with their effect sizes.

FINDINGS

In total, 42 meta-analyses published in the past 6 years and encompassing 81 outcomes were included. For the detection component, CHR-P individuals were young (mean [SD] age, 20.6 [3.2] years), were more frequently male (58%), and predominantly presented with attenuated psychotic symptoms lasting for more than 1 year before their presentation at specialized services. CHR-P individuals accumulated several sociodemographic risk factors compared with control participants. Substance use (33% tobacco use and 27% cannabis use), comorbid mental disorders (41% with depressive disorders and 15% with anxiety disorders), suicidal ideation (66%), and self-harm (49%) were also frequently seen in CHR-P individuals. CHR-P individuals showed impairments in work (Cohen d = 0.57) or educational functioning (Cohen d = 0.21), social functioning (Cohen d = 1.25), and quality of life (Cohen d = 1.75). Several neurobiological and neurocognitive alterations were confirmed in this study. For the prognosis component, the prognostic accuracy of CHR-P instruments was good, provided they were used in clinical samples. Overall, risk of psychosis was 22% at 3 years, and the risk was the highest in the brief and limited intermittent psychotic symptoms subgroup (38%). Baseline severity of attenuated psychotic (Cohen d = 0.35) and negative symptoms (Cohen d = 0.39) as well as low functioning (Cohen d = 0.29) were associated with an increased risk of psychosis. Controlling risk enrichment and implementing sequential risk assessments can optimize prognostic accuracy. For the intervention component, no robust evidence yet exists to favor any indicated intervention over another (including needs-based interventions and control conditions) for preventing psychosis or ameliorating any other outcome in CHR-P individuals. However, because the uncertainty of this evidence is high, needs-based and psychological interventions should still be offered.

CONCLUSIONS AND RELEVANCE

This review confirmed recent substantial advancements in the detection and prognosis of CHR-P individuals while suggesting that effective indicated interventions need to be identified. This evidence suggests a need for specialized services to detect CHR-P individuals in primary and secondary care settings, to formulate a prognosis with validated psychometric instruments, and to offer needs-based and psychological interventions.

Stressor-Cortisol Concordance Among Individuals at Clinical High-Risk for Psychosis: Novel Findings from the NAPLS Cohort

Whilst elevations in basal cortisol levels have been reported among individuals at-risk for psychosis, the extent to which this represents hyperresponsivity of the hypothalamic-pituitary-adrenal (HPA) axis to psychosocial stressors encountered in the natural environment is currently unclear. We aimed to examine stressor-cortisol concordance among youth at clinical high-risk (CHR) for psychosis in the North American Prodrome Longitudinal Study 2 (NAPLS 2) and the relationship with clinical outcome. At baseline, CHR (N = 457) and healthy (N = 205) individuals provided salivary cortisol samples and completed daily stressor, life event, and childhood trauma measures. CHR youth were categorised as remitted, symptomatic, progression of positive symptoms, or psychosis conversion at the two-year follow-up. Within-group regression models tested associations between psychosocial stressors and cortisol; standardised beta coefficients (Stβ) were subsequently derived to enable within-group pooling of effect sizes across stressor types. After adjustment for potential confounders, all CHR subgroups reported greater exposure to life events and daily stressors, and more distress in relation to these events, relative to controls. All CHR groups were also more likely to experience childhood trauma; only CHR converters, however, were characterised by elevated basal cortisol. Daily stressor distress was significantly associated with cortisol in controls (β = 0.60, 95% CI: 0.12-1.08) and CHR youth who converted to psychosis (β = 0.91, 95% CI: 0.05-1.78). In controls only, life event exposure was associated with cortisol (β = 0.45, 95% CI: 0.08-0.83). When pooled across stressors, stressor-cortisol concordance was substantially higher among CHR converters (Stβ = 0.26, 95% CI: 0.07 to 0.44) relative to CHR progressed (Stβ = 0.02, 95% CI: -0.11 to 0.15), symptomatic (Stβ = 0.01, 95% CI: -0.11 to 0.12), and remitted groups (Stβ = 0.00, 95% CI: -0.13 to 0.13); however, unexpectedly, healthy controls showed intermediate levels of concordance (Stβ = 0.15, 95% CI: 0.05 to 0.26). In conclusion, whilst all CHR subgroups showed increased psychosocial stress exposure and distress relative to controls, only those who later converted to psychosis were characterised by significantly elevated basal cortisol levels. Moreover, only CHR converters showed a higher magnitude of stressor-cortisol concordance compared to controls, although confidence intervals overlapped considerably between these two groups. These findings do not support the notion that all individuals at CHR for psychosis show HPA hyperresponsiveness to psychosocial stressors. Instead, CHR individuals vary in their response to stressor exposure/distress, perhaps driven by genetic or other vulnerability factors.

Cortisol Responses to Naturally Occurring Psychosocial Stressors Across the Psychosis Spectrum: A Systematic Review and Meta-Analysis

BACKGROUND

Individuals with established psychosis and those at high-risk for the disorder have been found to show abnormalities within the hypothalamic-pituitary-adrenal (HPA) axis, including elevations in basal and diurnal cortisol, but a blunted cortisol awakening response. However, the extent to which these features are associated with psychosocial stressors encountered in the natural environment (which are known to be more commonly experienced by these groups, and more distressing) is currently unclear. We therefore conducted a systematic review and meta-analysis to investigate the concordance between naturally-occurring psychosocial stressors and cortisol levels in these populations.

METHODS

PubMed, PsycINFO, and EMBASE were searched up to November 2019 to identify studies examining the concordance between psychosocial stressors and cortisol in healthy controls and individuals on the psychosis spectrum (patients with established psychosis and/or high-risk individuals). An overall meta-analysis (including data for all stressor-cortisol pairings) was performed to determine the degree of concordance irrespective of group status, with meta-regression employed to test whether the degree of concordance differed in established psychosis and high-risk groups compared to controls. Planned stratified analyses were then performed to examine group differences (where established psychosis and high-risk groups were combined) within individual stressor-cortisol pairings.

RESULTS

Eighteen studies (16 datasets) were eligible for inclusion. The overall model, comprising 134 effect sizes, showed that stressors and cortisol measures were only weakly correlated [r=0.05 (95% CI: -0.00 to 0.10), p=0.059] and that neither established psychosis status (r=0.01, p=0.838) nor high-risk status (r=0.02, p=0.477) had a significant effect of the strength of correlation. In stratified analyses, significant differences between healthy controls and psychosis spectrum groups were observed for only one of the six stressor-cortisol pairings examined, where life event exposure and diurnal cortisol were positively correlated in controls [r=0.25 (95% CI: 0.01 to 0.46)], but negatively correlated in the psychosis spectrum group [r=-0.28 (95% CI: -0.49 to -0.04)].

CONCLUSIONS

Overall, we observed poor concordance between naturally-occurring psychosocial stressors and cortisol irrespective of stressor type, cortisol measure, or group status. We consider a range of methodological factors that may have obscured the ability to detect "true" associations and provide recommendations for future studies in this field.