Biological markers in clinical psychological research - A systematic framework applied to HPA axis regulation in PTSD

Cortisol in functional neurological disorders: State, trait and prognostic biomarkers

OBJECTIVE

Biological stress dysregulation, such as a flattened cortisol awakening response (CAR), has been identified in functional neurological disorder (FND). This longitudinal study aimed to explore whether CAR alterations in FND serve as state or trait biomarkers, assessing temporal changes in cortisol and clinical outcomes to test its prognostic value.

METHODS

Salivary cortisol was measured in 53 patients with mixed FND at two visits separated by eight months (M0 and M8). CAR was calculated based on five consecutive samples, each taken with 15-min time intervals, collected upon awakening, whereas cortisol amplitude (CAmp) was calculated as the difference between the morning peak and the afternoon trough. Clinical outcome was assessed with the Functional Movement Disorder Rating Scale (S-FMDRS), Clinical global impression (CGI) scores for severity (CGI-S) and improvement (CGI-I) and the short-form health survey (SF-36).

RESULTS

No differences in CAR levels were found between M0 and M8 regardless of clinical outcome (remained flattened). However, a good clinical outcome was associated with an earlier peak in the CAR (p = .013, odds ratio: 1.78; 95%-confidence interval: 0.095-1.13). A higher CAmp at M0 predicted a better outcome at M8 (β = 1.14, 95%-confidence interval:0.15-2.13, p = .03).

CONCLUSION

A flattened CAR might represent a trait marker for FND, when an earlier peak in the CAR may serve as a state biomarker. The CAmp demonstrates predictive power for clinical outcome, potentially representing a prognostic biomarker for FND. Further replication and follow-up studies are essential to confirm this suggested role of cortisol as a multifaceted biomarker of FND.

Cross-sectional associations between patterns of cultural engagement and indicators of biological dysregulation

BACKGROUND

Research has shown that cultural activities may bring about improved health. However, large-scale quantitative analyses on cultural engagement and biomarkers are lacking to date. As a result, the mechanisms through which cultural activities may be associated with health are unclear.

AIM

Test quantitative associations between cultural engagement pattern (including active and passive engagement in arts, sports, and heritage activities) and indicators of biological dysregulation in a large dataset.

SUBJECTS AND METHODS

Understanding Society data were used to conduct cross-sectional linear regression analyses between a data-driven latent class model of cultural engagement and indicators of anthropometric, cardiovascular, metabolic, immune, and neuroendocrine function. Analyses were adjusted for age, gender, ethnicity, childcare responsibility, urbanicity, leisure time satisfaction, capacity-related factors, socioeconomic position, social and economic capital indicators, physical activity, and medication use.

RESULTS

More culturally participants had better indicators of biological health, such as lower waist circumference and fibrinogen blood concentration. Specific associations between cultural engagement pattern and the different biological outcomes were also observed. The associations were explained in part by correlated factors (accounting for around half of the association).

CONCLUSIONS

Cultural engagement is cross-sectionally associated with biomarkers, although the characteristics of people who engage with culture are an important consideration when interpreting these findings.

Hair Cortisol Research in Posttraumatic Stress Disorder - 10 Years of Insights and Open Questions. A Systematic Review

BACKGROUND

Cortisol is one of the most extensively studied biomarkers in the context of trauma/posttraumatic stress disorder (PTSD). For more than a decade, hair cortisol concentrations (HCC) have been measured in this context, leading to a two-staged dysregulation model. Specifically, an elevated secretion during/immediately after trauma exposure eventually reverts to hyposecretion with increasing time since trauma exposure has been postulated.

OBJECTIVE

The aim of our systematic review was to re-evaluate the two-staged secretion model with regard to the accumulated diagnostic, prognostic, and intervention-related evidence of HCC in lifetime trauma exposure and PTSD. Further, we provide an overview of open questions, particularly with respect to reporting standards and quality criteria.

METHOD

A systematic literature search yielded 5,046 records, of which 31 studies were included.

RESULTS

For recent/ongoing (traumatic) stress, the predictions of cortisol hypersecretion could be largely confirmed. However, for the assumed hyposecretion temporally more distal to trauma exposure, the results are more ambiguous. As most studies did not report holistic overviews of trauma history and confounding influences, this may largely be attributable to methodological limitations. Data on the prognostic and intervention-related benefits of HCC remain sparse.

CONCLUSION

Over the last decade, important insights could be gained about long-term cortisol secretion patterns following lifetime trauma exposure and PTSD. This systematic review integrates these insights into an updated secretion model for trauma/PTSD. We conclude with recommendations for improving HCC research in the context of trauma/PTSD in order to answer the remaining open questions.

Hair cortisol as outcome parameter for psychological and neuropsychiatric interventions-a literature review

Background

Studies measuring hair cortisol concentration (HCC) have been increasingly conducted to document stress-related, endocrine changes aggregated over time. Previous studies have shown that HCC reflects abnormalities in the hypothalamic-pituitary-adrenocortical axis (HPA axis) in the context of somatic diseases, such as Cushing's syndrome. HCC variations also reveal a corresponding alteration in HPA-axis-function in mental disorders, highlighting its potential role as a biomarker for interventions targeting mental health problems.

Aims

The aim of this study was to investigate the role of HCC in various psychological and neuropsychiatric interventions and to explore the extent to which HCC can serve as a predictive or outcome parameter in such interventions by conducting a PRISMA-compliant review of the literature.

Methods

From May to July 2022, the databases Web of Science, Google Scholar, PsychINFO, and ResearchGate were systematically searched using different combinations of relevant keywords. Studies of different types that examined HCC in the context of a wide range of psychological and neuropsychiatric interventions were included. Studies in languages other than English or German and animal studies were excluded. The MMAT tool was used, to assesses the Risk of bias.

Results

The initial search identified 334 studies. After applying the inclusion and exclusion criteria, 14 publications with a total number of 1,916 participants were identified. An association between HCC and PTSD, depressive disorders, and ongoing social and family stress can be documented. The effect of relaxation techniques, mental training, CBT, or PTSD therapy on HCC has been studied with equivocal results. Some studies found decreased HCC after treatment, while others did not show a clear effect. Baseline HCC appears to be of particular importance. In some studies, higher baseline HCC was associated with increased treatment response, providing a predictive value for HCC.

Discussion

HCC is increasingly being used as a biomarker for the mapping of psychological and neuropsychiatric interventions. However, due to the wide range of study populations and interventions, results are still heterogeneous. Nevertheless, HCC seems to be an encouraging biological parameter to describe the trajectory of different interventions aimed at improving mental health.

Comparative efficacy of psychological interventions on immune biomarkers: A systematic review and network meta-analysis (NMA)

Psychological interventions are viable, cost-effective strategies for improving clinical and psychological impact of inflammation-related conditions. However, their efficacy on immune system function remains controversial. We performed a systematic review and frequentist random-effects network meta-analysis of randomised controlled trials (RCTs) assessing the effects of psychological interventions, against a control condition, on biomarkers of innate and adaptive immunity in adults. PubMed, Scopus, PsycInfo, and Web of Science were searched from inception up to Oct 17, 2022. Cohen's d at 95% confidence interval (CI) was calculated to assess the effect sizes of each class of intervention against active control conditions at post-treatment. The study was registered in PROSPERO (CRD42022325508). Of the 5024 articles retrieved, we included 104 RCTs reporting on 7820 participants. Analyses were based on 13 types of clinical interventions. Compared with the control conditions, cognitive therapy (d =  - 0.95, 95% CI: -1.64 to - 0.27), lifestyle (d =  - 0.51, 95% CI: -0.99 to - 0.02), and mindfulness-based (d =  - 0.38, 95% CI: -0.66 to - 0.09) interventions were associated with post-treatment reduction of proinflammatory cytokines and markers. Mindfulness-based interventions were also significantly associated with post-treatment increase in anti-inflammatory cytokines (d = 0.69, 95% CI: 0.09 to 1.30), while cognitive therapy was associated also with post-treatment increase in white blood cell count (d = 1.89, 95% CI: 0.05 to 3.74). Results on natural killer cells activity were non-significant. Grade of evidence was moderate for mindfulness and low-to-moderate for cognitive therapy and lifestyle interventions; however, substantial overall heterogeneity was detected in most of the analyses.

The effect of an internet-based intervention for depression on cortisol and alpha-amylase

INTRODUCTION

Psychotherapeutic interventions for major depressive disorder (MDD) have been suggested to be associated with a normalization of biological stress system (i.e., the hypothalamic-pituitary-adrenal axis and the autonomic nervous system) dysregulation. Furthermore, pre-intervention cortisol parameters have been identified as prescriptive biological markers of treatment success. However, evidence of treatment effects on the biological stress systems is still sparse, and results are heterogeneous. The current study examined the effect of an internet-based intervention for MDD on salivary cortisol and alpha-amylase as well as hair cortisol concentrations. Moreover, the prescriptive capacity of pre-intervention cortisol and alpha-amylase concentrations on treatment response was explored.

METHODS

Thirty-eight participants suffering from mild to moderate MDD collected saliva and hair samples throughout the intervention. Biological outcome parameters were salivary cortisol and alpha-amylase (awakening response, total diurnal output, diurnal slope) and hair cortisol concentrations. Treatment response was indicated by change in depression severity and perceived chronic stress.

RESULTS

Treatment response on depression scores or chronic stress was not associated with changes in any of the cortisol or alpha-amylase parameters. Exploratory analysis indicated that non-responders showed a steeper alpha-amylase slope pre-intervention.

DISCUSSION

The results indicate that changes in depressive symptoms did not correspond to changes of the biological stress systems, contradicting the suggested normalization of dysregulated hypothalamic-pituitary-adrenal axis or autonomic nervous system activity through a psychotherapeutic intervention. However, the results point to a potential role of pre-intervention alpha-amylase slope as a prescriptive marker of treatment response for depression.

Changes in the Serum Concentration Levels of Serotonin, Tryptophan and Cortisol among Stress-Resilient and Stress-Susceptible Individuals after Experiencing Traumatic Stress

BACKGROUND

Stress is a common response to many environmental adversities. However, once dysregulated, this reaction can lead to psychiatric illnesses, such as post-traumatic stress disorder (PTSD). Individuals can develop PTSD after exposure to traumatic events, severely affecting their quality of life. Nevertheless, not all individuals exposed to stress will develop psychiatric disorders, provided they show enhanced stress-resilience mechanisms that enable them to successfully adapt to stressful situations and thus avoid developing a persistent psychopathology.

METHODS

The study involved 93 participants. Of them, 62 comprised a study group and 31 comprised a control group. The aim of the study was to assess serotonin, cortisol and tryptophan concentration levels in subjects with PTSD (stress-susceptible; PTSD-SS) and in healthy individuals (stress-resilient; PTSD-SR), who had experienced a traumatic event but fully recovered after the trauma. The subjects were between 18 and 50 years of age (mean 35.56 ± 8.26 years). The serum concentration levels of serotonin, cortisol and tryptophan were measured with an ELISA kit.

RESULTS

It was found that the serotonin, tryptophan and cortisol concentration levels were consistent with the features of both PTSD-SR and PTSD-SS patients. It was reported that the mean cortisol concentration levels increased more significantly in the PTSD-SS group than in the PTSD-SR group, versus those in the control group. Similarly, the PTSD-SS group was found to show a larger decrease in the mean serotonin concentration levels than the PTSD-SR group, versus those in the control group. No significant changes were found in the tryptophan concentration levels between the study groups, versus those in the control group.

CONCLUSIONS

These findings can be useful when attempting to improve resilience in individuals using neuropharmacological methods. However, it is necessary to conduct more cross-sectional studies that would address different types of negative stress to find out whether they share common pathways.