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

Salivary cortisol measures across the clinical stages of psychosis: An individual participant data (IPD) meta-analysis

BACKGROUND

Studies of salivary cortisol levels in psychosis have yielded inconsistent findings, which may be attributable to heterogeneity in cortisol measurement, illness stage, and approaches to dealing with sampling factors and potential confounders. To address these issues, we performed an individual participant data (IPD) meta-analysis comparing individuals at different stages of psychosis to controls using five different salivary cortisol measures and explored potential effect modifiers.

METHODS

Salivary cortisol data from five London-based cohorts were used to derive the cortisol awakening response, total daytime cortisol output, basal cortisol, and diurnal slope measures (wake-to-evening and peak-to-evening). Linear regression models were first performed to obtain standardised beta coefficients (β), representing the difference in each cortisol metric between each clinical stage group (cases) and healthy individuals (controls) after accounting for relevant sampling factors; we then used random-effects meta-analyses and meta-regression models to investigate the effect of psychosis stage and sample characteristics on effect sizes.

RESULTS

Data were available for 352 individuals distributed across psychosis clinical stages (1a - distress disorder: N = 35; 1b - clinical high-risk for psychosis: N = 90; 2a - first-episode psychosis: N = 197; 2b - single episode remitted: N = 5; 3 - relapsing/remitting illness: N = 18; 4 - severe and persistent illness: N = 7) and 292 controls. A significant overall main effect of clinical stage on peak-to-evening diurnal slope was observed (χ2=12.83, p = 0.025), with both the clinical high-risk (β=0.21, 95 % CI: 0.06, 0.36) and first-episode psychosis (β=0.20, 95 % CI: 0.10, 0.31) groups characterised by flatter slopes than controls. The clinical stage groups and controls did not differ on any other cortisol measure. Several sample characteristics were significantly associated with diurnal slope effect sizes, but after accounting for clinical stage, only the association between mean age in cases and wake-to-evening diurnal slope retained significance.

CONCLUSION

Clinical high-risk and first-episode psychosis participants differed from healthy controls in the peak-to-evening diurnal cortisol slope. This measure has not been examined in these populations before, and its potential predictive and prognostic utility for psychotic disorders merits further investigation.

Cortisol in schizophrenia spectrum disorders: A comprehensive meta-analysis

Schizophrenia spectrum disorders (SSD) are characterized by alterations in cortisol levels across various parameters, including stress reactivity, hair cortisol, and baseline levels, which may be influenced by antipsychotic treatment. To provide a comprehensive overview of cortisol dysregulation in SSD, we conducted meta-analyses assessing (1) the effects of antipsychotic treatment in SSD patients, and additionally comparing cortisol in SSD patients versus healthy controls (HC) (2) following stress induction (metabolic, physiological, psychological stressors), (3) in hair and (4) baseline levels. Systematic literature searches in PubMed, Web of Science, and PsycINFO (November 2024) identified 121 studies (9049 SSD patients) for inclusion. Meta-analytic results revealed that antipsychotic treatment significantly reduced cortisol levels in SSD (k = 16, g = -0.480, 95 % CI [-0.818, -0.142], p = 0.005). Additionally, compared to HC, SSD was associated with reduced cortisol suppression following dexamethasone exposure (k = 9, g = 0.299, 95 % CI [0.091, 0.507], p = 0.005) and with elevated baseline cortisol levels in the morning (k = 71, g = 0.38, 95 % CI [0.210, 0.546], p < 0.001) and evening (k = 11, g = 0.368, 95 % CI [0.076, 0.661], p = 0.014). However, there were no significant group differences in afternoon baseline cortisol, hair cortisol or cortisol reactivity to stress (p > 0.05). These findings offer a detailed understanding of cortisol alterations in SSD and improve our understanding of HPA axis dysregulation in SSD.

Exposotypes in Psychotic Disorders

Psychiatry lags in adopting etiological approaches to diagnosis, prognosis, and outcome prediction compared to the rest of medicine. Etiological factors such as childhood trauma (CHT), substance use (SU), and socioeconomic status (SES) significantly affect psychotic disorder symptoms. This study applied an agnostic clustering approach to identify exposome clusters "Exposotypes (ETs)" and examine their relationship with clinical, cognitive, and functional outcomes. Using data from individuals with psychotic disorders (n=1,350), and controls (n=623), we assessed the relationship between the exposotypes and outcomes. Four exposotypes were identified: ET1 characterized by high CHT and SU; ET2, high CHT; ET3, high SU; ET4, low exposure. Compared to ET4, ET1 demonstrated higher positive and general symptoms, anxiety, depression, impulsivity, and mania; ET2 had higher anxiety, depression, and impulsivity; ET3 had better cognitive and functional outcomes with lower negative symptoms. Intracranial volume was largest in ET3, and smallest in ET2. No group differences in schizophrenia polygenic risk scores were found. The age of onset was 5 years earlier in ET1 than in ET4. These findings provide insight into the complex etiological interplay between trauma, and SU, as well as their unique effects on clinical symptoms, cognition, neurobiology, genetic risk, and functioning.

Exploring causal mechanisms of psychosis risk

Robust epidemiological evidence of risk and protective factors for psychosis is essential to inform preventive interventions. Previous evidence syntheses have classified these risk and protective factors according to their strength of association with psychosis. In this critical review we appraise the distinct and overlapping mechanisms of 25 key environmental risk factors for psychosis, and link these to mechanistic pathways that may contribute to neurochemical alterations hypothesised to underlie psychotic symptoms. We then discuss the implications of our findings for future research, specifically considering interactions between factors, exploring universal and subgroup-specific factors, improving understanding of temporality and risk dynamics, standardising operationalisation and measurement of risk and protective factors, and developing preventive interventions targeting risk and protective factors.

Admissions for psychosis following agency-notified child maltreatment at 40-year-follow-up: Results from the Childhood Adversity and Lifetime Morbidity (CALM) cohort

There is substantial evidence of an association between self-reported child maltreatment (CM) and subsequent psychosis in retrospective data. Such findings may be affected by recall bias. Prospective studies of notifications to statutory agencies address recall bias but are less common and subject to attrition bias. These studies may therefore be underpowered to detect significant associations for some CM types such as sexual abuse. This study therefore linked administrative health data to a large birth cohort that included notifications to child protection agencies. We assessed psychiatric outcomes of CM as measured by inpatient admissions for non-affective psychoses (ICD10 codes F20-F29) to both public and private hospitals in Brisbane, Australia. Follow-up was up to 40 years old. There were 6087 cohort participants whose data could be linked to the administrative health data. Of these, 10.1 % had been the subject of a CM notification. Seventy-two participants (1.2 %) had been admitted for non-affective psychosis by 40-year follow-up. On adjusted analysis, all notified and substantiated types of CM were associated with admissions for non-affective psychosis. This included neglect, physical, sexual or emotional abuse, as well as notifications for multiple CM types. For instance, there was a 2.72-fold increase in admissions following any agency notification (95 % CI = 1.53-4.85). All maltreatment types therefore show a significant association with subsequent admissions for psychosis up to the age of 40. Screening for CM in individuals who present with psychosis is, therefore, indicated, as well as greater awareness that survivors of CM may be at higher risk of developing psychotic symptoms.

Psychosocial stress moderates the relationship between cerebrospinal fluid lactate dehydrogenase and the duration of untreated psychosis in first-episode psychosis

Introduction

Previous research has shown that lower lactate dehydrogenase (LDH) concentrations in cerebrospinal fluid (CSF) are associated with longer prodromal symptoms in first-episode psychosis (FEP). We aimed to study whether there is a relationship between the duration of untreated psychosis (DUP) and LDH and other CSF biomarkers in FEP and whether stressful life events moderate this association.

Methods

Ninety-five inpatients with FEP and with less than 6 weeks of antipsychotic treatment were included in the study. All participants were informed about the nature of the study, which was approved by the local ethics committee, and signed an informed consent form. A lumbar puncture was performed at index admission (baseline) to measure CSF parameters (glucose, total protein, LDH). The DUP was assessed with the Quick Psychosis Onset and Prodromal Symptoms Inventory (Q-POPSI). Stressful life events (SLEs) in the previous 6 months were assessed with the List of Threatening Experiences. We dichotomized the SLE variable into having experienced at least one SLE or no experience of SLEs. Statistical analyses were performed with SPSS v. 25.0. Total protein and LDH concentrations were natural log transformed (ln) to reduce skewness. Multiple linear regression analyses were conducted to explore the association between the DUP and CSF parameters (considered the dependent variable). Age, sex, DUP and SLEs were considered independent variables. We tested the DUP by SLE interaction. Significant interactions were included in the final model. The threshold for significance was set at p<0.05.

Results

Fifty-four FEP patients (56.8%) reported an SLE in the previous 6 months. There were no significant differences in the DUP between patients with or without SLEs. There were no significant differences in CSF biomarkers between the SLE groups. In the multiple linear regression analyses, we found a significant DUP by SLE interaction effect on CSF LDH concentrations (standardized beta= -0.320, t= -2.084, p= 0.040). In patients with SLEs, a shorter DUP was associated with higher CSF LDH concentrations and vice versa. No significant associations were found between the DUP or SLEs and other CSF biomarkers (glucose, total proteins).

Conclusions

Our study suggests that psychosocial stress moderates the relationship between the onset of psychosis and CSF biomarkers related to bioenergetic systems.