Nocturnal urinary cortisol excretion over a randomized controlled trial with paroxetine vs. placebo combined with relaxation training or aerobic exercise in panic disorder

Peripheral Biomarkers in DSM-5 Anxiety Disorders: An Updated Overview

Anxiety disorders are prevalent and highly disabling mental disorders. In recent years, intensive efforts focused on the search for potential neuroimaging, genetic, and peripheral biomarkers in order to better understand the pathophysiology of these disorders, support their diagnosis, and characterize the treatment response. Of note, peripheral blood biomarkers, as surrogates for the central nervous system, represent a promising instrument to characterize psychiatric disorders, although their role has not been extensively applied to clinical practice. In this report, the state of the art on peripheral biomarkers of DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th edition) Anxiety Disorders is presented, in order to examine their role in the pathogenesis of these conditions and their potential application for diagnosis and treatment. Available data on the cerebrospinal fluid and blood-based biomarkers related to neurotransmitters, neuropeptides, the hypothalamic-pituitary-adrenal axis, neurotrophic factors, and the inflammation and immune system are reviewed. Despite the wide scientific literature and the promising results in the field, only a few of the proposed peripheral biomarkers have been defined as a specific diagnostic instrument or have been identified as a guide in the treatment response to DSM-5 Anxiety Disorders. Therefore, further investigations are needed to provide new biological insights into the pathogenesis of anxiety disorders, to help in their diagnosis, and to tailor a treatment.

Biological markers for anxiety disorders, OCD and PTSD: A consensus statement. Part II: Neurochemistry, neurophysiology and neurocognition

OBJECTIVE

Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD).

METHODS

Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network.

RESULTS

The present article (Part II) summarises findings on potential biomarkers in neurochemistry (neurotransmitters such as serotonin, norepinephrine, dopamine or GABA, neuropeptides such as cholecystokinin, neurokinins, atrial natriuretic peptide, or oxytocin, the HPA axis, neurotrophic factors such as NGF and BDNF, immunology and CO2 hypersensitivity), neurophysiology (EEG, heart rate variability) and neurocognition. The accompanying paper (Part I) focuses on neuroimaging and genetics.

CONCLUSIONS

Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high quality research has accumulated that should improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD.

Cortisol as a predictor of psychological therapy response in anxiety disorders-Systematic review and meta-analysis

BACKGROUND

Although psychotherapy generally is effective in anxiety disorders, many patients are treatment-resistant. At the same time, some patients with anxiety disorders show alterations in the hypothalamic-pituitary-adrenal (HPA) axis, one of the major stress-responsive systems. Since raised levels of the end product of the HPA axis, cortisol, adversely affect cognition, we hypothesised that more pronounced alterations in cortisol levels would be associated with a less favourable response to psychotherapy. More specifically, the higher patients' basal levels and the lower their levels during exposure, the less likely we expected them to profit from treatment.

METHODS

We systematically searched the Cochrane Library, EMBASE, MEDLINE, and PsycINFO to review the literature and perform a meta-analysis on the relationship between pre-treatment cortisol and psychotherapy response. Records were included if they studied patients with any anxiety disorder undergoing psychotherapy, with a pre-treatment cortisol and a post-treatment symptom measure. Correlation coefficients were extracted for meta-analyses.

RESULTS

We identified six studies (N=274). No relationship between patients' basal cortisol and post-treatment symptoms was found (p=0.981). The systematic review showed higher cortisol during exposure sessions to predict better outcomes. Meta-analysis did not confirm this (p=0.603).

CONCLUSIONS

Basal cortisol did not seem to predict psychological therapy responses in patients with anxiety disorders. By contrast, the current state of research is equivocal in terms of whether higher cortisol concentrations during exposure sessions are linked with better treatment outcomes, and more research is needed to investigate this.

Exercise as Treatment for Anxiety: Systematic Review and Analysis

BACKGROUND

Exercise has been shown to reduce symptoms of anxiety, but few studies have studied exercise in individuals preselected because of their high anxiety.

PURPOSE

The objective of this study is to review and critically evaluate studies of exercise training in adults with either high levels of anxiety or an anxiety disorder.

METHODS

We conducted a systematic review of randomized clinical trials (RCTs) in which anxious adults were randomized to an exercise or nonexercise control condition. Data were extracted concerning anxiety outcomes and study design. Existing meta-analyses were also reviewed.

RESULTS

Evidence from 12 RCTs suggested benefits of exercise, for select groups, similar to established treatments and greater than placebo. However, most studies had significant methodological limitations, including small sample sizes, concurrent therapies, and inadequate assessment of adherence and fitness levels.

CONCLUSIONS

Exercise may be a useful treatment for anxiety, but lack of data from rigorous, methodologically sound RCTs precludes any definitive conclusions about its effectiveness.

Effect of combined cognitive-behavioural therapy and endurance training on cortisol and salivary alpha-amylase in panic disorder

Current data point to an alteration of both the hypothalamo-pituitary-adrenal (HPA)-system and the peripheral transmission of catecholamines in anxiety disorders. There is also some evidence for the effect of several components of cognitive-behavioural interventions such as coping and control and for an effect of exercise training on the neuroendocrine stress response in healthy subjects as well as patients suffering from distinct (mental) disorders. This double-blind, controlled study investigated the effect of cognitive-behavioural therapy (CBT) in combination with either high-level endurance training or low-level exercise on salivary cortisol (sC) and on levels of salivary alpha-amylase (sAA) in patients suffering from panic disorder (PD) with and without agoraphobia. In comparison to the low-level exercise condition, there were significantly lower sC-levels in the experimental group performing high-level endurance training at a 7-month follow-up. In contrast, there were no group differences in sAA levels during the study period. In this trial, we found evidence for a decelerated effect of endurance-training on HPA-system's functioning in PD. Further studies addressing the alteration of sAA levels in this population might investigate physical exercise different in intensity and duration.

Investigation of cortisol levels in patients with anxiety disorders: a structured review

Anxiety disorders are common and distressing medical conditions, which typically arise in adolescence or early adult life. They can persist for many years, reducing quality of life, limiting academic and occupational achievement, and being responsible for considerable economic pressures. Although a range of psychological and pharmacological treatments are available, their success is often limited, and many patients remain troubled by significant symptom-related disability for long periods. The detailed pathophysiology of each anxiety disorder is not established, and novel treatments that are based solely on current understanding of conventional neurotransmitter function are unlikely to be substantially more effective or better tolerated than current treatments. Investigations of hypothalamo-pituitary axis function across panic disorder, generalized anxiety disorder, specific phobias and social anxiety disorder have produced intriguing findings but not revealed a consistent pattern of endocrine disturbance, perhaps reflecting differences in methodology and the nature and size of the clinical samples. There is a persistent need for large, prospective studies using standardized methods for investigation and data analysis (164 words).