Joshua Curtiss

A Complex Network Perspective on Clinical Science

Contemporary classification systems for mental disorders assume that abnormal behaviors are expressions of latent disease entities. An alternative to the latent disease model is the complex network approach. Instead of assuming that symptoms arise from an underlying disease entity, the complex network approach holds that disorders exist as systems of interrelated elements of a network. This approach also provides a framework for the understanding of therapeutic change. Depending on the structure of the network, change can occur abruptly once the network reaches a critical threshold (the tipping point). Homogeneous and highly connected networks often recover more slowly from local perturbations when the network approaches the tipping point, potentially making it possible to predict treatment change, relapse, and recovery. In this article, we discuss the complex network approach as an alternative to the latent disease model and its implications for classification, therapy, relapse, and recovery.

Neuroenhancement of Exposure Therapy in Anxiety Disorders

Although exposure-based treatments and anxiolytic medications are more effective than placebo for treating anxiety disorders, there is still considerable room for further improvement. Interestingly, combining these two modalities is usually not more effective than the monotherapies. Recent translational research has identified a number of novel approaches for treating anxiety disorders using agents that serve as neuroenhancers (also known as cognitive enhancers). Several of these agents have been studied to determine their efficacy at improving treatment outcome for patients with anxiety and other psychiatric disorders. In this review, we examine d-cycloserine, yohimbine, cortisol, catecholamines, oxytocin, modafinil, and nutrients such as caffeine and amino fatty acids as potential neuroenhancers. Of these agents, d-cycloserine shows the most promise as an effective neuroenhancer for extinction learning and exposure therapy. Yet, the optimal dosing and dose timing for drug administration remains uncertain. There is partial support for cortisol, catecholamines, yohimbine and oxytocin for improving extinction learning and exposure therapy. There is less evidence to indicate that modafinil and nutrients such as caffeine and amino fatty acids are effective neuroenhancers. More research is needed to determine their long term efficacy and clinical utility of these agents.

Effect of Hatha yoga on anxiety: a meta‐analysis

Some evidence suggests that Hatha yoga might be an effective practice to reduce anxiety. To examine the effect of Hatha yoga on anxiety, we conducted a meta‐analysis of relevant studies extracted from PubMed, PsycINFO, the Cochrane Library, and manual searches.

The conditional process model of mindfulness and emotion regulation: An empirical test

BACKGROUND The conditional process model (CPM) of mindfulness and emotion regulation posits that specific mediators and moderators link these constructs to mental health outcomes. The current study empirically examined the central tenets of the CPM, which posit that nonreactivity moderates the indirect effect of observation on symptoms of emotional disorders through cognitive emotion regulation strategies. METHODS A clinical sample (n=1667) of individuals from Japan completed a battery of self-report instruments. Several path analyses were conducted to determine whether cognitive emotion regulation strategies mediate the relationship between observation and symptoms of individual emotional disorders, and to determine whether nonreactivity moderated these indirect effects. RESULTS Results provided support the CPM. Specifically, nonreactivity moderated the indirect effect of observation on symptoms through reappraisal, but it did not moderate the indirect effect of observation on symptoms through suppression. LIMITATIONS Causal interpretations are limited, and cultural considerations must be acknowledged given the Japanese sample CONCLUSIONS: These results underscore the potential importance of nonreactivity and emotion regulation as targets for interventions.

Interpersonal Emotion Regulation Questionnaire (IERQ): Scale Development and Psychometric Characteristics.

Despite the popularity of emotion regulation in the contemporary literature, research has almost exclusively focused on intrapersonal processes, whereas much less attention has been placed on interpersonal emotion regulation processes. In order to encourage research on interpersonal emotion regulation, we present a series of four studies to develop the Interpersonal Emotion Regulation Questionnaire (IERQ). The final scale consists of 20 items with 4 factors containing five items each. The four factors are: Enhancing Positive Affect; Perspective Taking; Soothing; and Social Modeling. The scale shows excellent psychometric characteristics. Implications for future research are discussed.

A meta-analysis of pharmacotherapy for social anxiety disorder: an examination of efficacy, moderators, and mediators

ABSTRACT Introduction: Social anxiety disorder (SAD) is among the most prevalent mental disorders, associated with impaired functioning and poor quality of life. Pharmacotherapy is the most widely utilized treatment option. The current study provides an updated meta-analytic review of the efficacy of pharmacotherapy and examines moderators and mediators of treatment efficacy. Areas Covered: A comprehensive search of the current literature yielded 52 randomized, pill placebo-controlled trials of pharmacotherapy for adults diagnosed with SAD. Data on potential mediators of treatment outcome were collected, as well as data necessary to calculate pooled correlation matrices to compute indirect effects. Expert Opinion: The overall effect size of pharmacotherapy for SAD is small to medium (Hedges’ g = 0.41). Effect sizes were not moderated by age, sex, length of treatment, initial severity, risk of study bias, or publication year. Furthermore, reductions in symptoms mediated pharmacotherapy’s effect on quality of life. Support was found for reverse mediation. Future directions may include sustained efforts to examine treatment mechanisms of pharmacotherapy using rigorous longitudinal methodology to better establish temporal precedence.

Yoga for generalized anxiety disorder: design of a randomized controlled clinical trial

Generalized anxiety disorder (GAD) is a common disorder associated with significant distress and interference. Although cognitive behavioral therapy (CBT) has been shown to be the most effective form of psychotherapy, few patients receive or have access to this intervention. Yoga therapy offers another promising, yet under-researched, intervention that is gaining increasing popularity in the general public, as an anxiety reduction intervention. The purpose of this innovative clinical trial protocol is to investigate the efficacy of a Kundalini Yoga intervention, relative to CBT and a control condition. Kundalini yoga and CBT are compared with each other in a noninferiority test and both treatments are compared to stress education training, an attention control intervention, in superiority tests. The sample will consist of 230 individuals with a primary DSM-5 diagnosis of GAD. This randomized controlled trial will compare yoga (N=95) to both CBT for GAD (N=95) and stress education (N=40), a commonly used control condition. All three treatments will be administered by two instructors in a group format over 12 weekly sessions with four to six patients per group. Groups will be randomized using permuted block randomization, which will be stratified by site. Treatment outcome will be evaluated bi-weekly and at 6month follow-up. Furthermore, potential mediators of treatment outcome will be investigated. Given the individual and economic burden associated with GAD, identifying accessible alternative behavioral treatments will have substantive public health implications.

Effect of treatments for depression on quality of life: a meta-analysis*

Abstract Cognitive-behavioral therapy (CBT) and selective serotonin reuptake inhibitors (SSRIs) are the two first-line treatments for depression, but little is known about their effects on quality of life (QOL). A meta-analysis was conducted to examine changes in QOL in adults with major depressive disorder who received CBT (24 studies examining 1969 patients) or SSRI treatment (13 studies examining 4286 patients) for their depression. Moderate improvements in QOL from pre to post-treatment were observed in both CBT (Hedges’ g = .63) and SSRI (Hedges’ g = .79) treatments. The effect size remained stable over the course of the follow-up period for CBT. No data were available to examine follow-ups in the SSRI group. QOL effect sizes decreased linearly with publication year, and greater improvements in depression were significantly associated with greater improvements in QOL for CBT, but not for SSRIs. CBT and SSRIs for depression were both associated with moderate improvements in QOL, but are possibly caused by different mechanisms.

Effect of regulating anger and sadness on decision-making

Abstract The aim of the current study was to investigate the effects of reappraisal, acceptance, and rumination for regulating anger and sadness on decision-making. Participants (N = 165) were asked to recall two autobiographical events in which they felt intense anger and sadness, respectively. Participants were then instructed to reappraise, accept, ruminate, or not use any strategies to regulate their feelings of anger and sadness. Following this manipulation, risk aversion, and decision-making strategies were measured using a computer-based measure of risk-taking and a simulated real-life decision-making task. Participants who were instructed to reappraise their emotions showed the least anger and sadness, the most adaptive decision-making strategies, but the least risk aversion as compared to the participants in the other conditions. These findings suggest that emotion regulation strategies of negative affective states have an immediate effect on decision-making and risk-taking behaviors.

Exercise and emotion dynamics: An experience sampling study.

Though it has been widely demonstrated that regular exercise is associated with better emotional wellbeing, the nature of this association remains unclear. The present study explored the relationship between voluntary exercise and the temporal dynamics of daily emotions, and thus how voluntary exercise could be impacting emotional reactivity and recovery in naturalistic contexts. Seventy-six young adults participated simultaneously in this ecological momentary assessment study, and received 75 prompts over the course of 15 days. Emotional inertia (persistence of emotional states), emotional variability (intensity of emotional fluctuations), and emotional instability (tendency for emotional fluctuations) were considered. Past research has shown that low wellbeing tends to be associated with high inertia, variability, and instability. Each prompt included ratings of present emotions (anxiety, sadness, cheerfulness, contentment) and any recent physical activity. Greater average exercise time was significantly associated with less inertia (reduced autocorrelation) of anxiety. Exercise was not significantly associated with inertia of the other emotions, although results were in the same direction. Exercise habits were unrelated to emotional variability and instability. Results suggest that exercise may buffer against prolonged or persistent negative affective states and consequently could benefit a persons ability to self-regulate or recover from changes in the environment and internal emotional experiences, rather than simply reducing the frequency or intensity of anxious emotions. (PsycINFO Database Record (c) 2019 APA, all rights reserved).