Psychological stress and the human immune system: a meta-analytic study of 30 years of inquiry

The present report meta-analyzes more than 300 empirical articles describing a relationship between psychological stress and parameters of the immune system in human participants. Acute stressors (lasting minutes) were associated with potentially adaptive upregulation of some parameters of natural immunity and downregulation of some functions of specific immunity. Brief naturalistic stressors (such as exams) tended to suppress cellular immunity while preserving humoral immunity. Chronic stressors were associated with suppression of both cellular and humoral measures. Effects of event sequences varied according to the kind of event (trauma vs. loss). Subjective reports of stress generally did not associate with immune change. In some cases, physical vulnerability as a function of age or disease also increased vulnerability to immune change during stressors.     

Acceptance- and mindfulness-based interventions for the treatment of chronic pain: a meta-analytic review

The number of acceptance- and mindfulness-based interventions for chronic pain, such as acceptance and commitment therapy (ACT), mindfulness-based stress reduction (MBSR), and mindfulness-based cognitive therapy (MBCT), increased in recent years. Therefore an update is warranted of our former systematic review and meta-analysis of studies that reported effects on the mental and physical health of chronic pain patients. Pubmed, EMBASE, PsycInfo and Cochrane were searched for eligible studies. Current meta-analysis only included randomized controlled trials (RCTs). Studies were rated for quality. Mean quality did not improve in recent years. Pooled standardized mean differences using the random-effect model were calculated to represent the average intervention effect and, to perform subgroup analyses. Outcome measures were pain intensity, depression, anxiety, pain interference, disability and quality of life. Included were twenty-five RCTs totaling 1285 patients with chronic pain, in which we compared acceptance- and mindfulness-based interventions to the waitlist, (medical) treatment-as-usual, and education or support control groups. Effect sizes ranged from small (on all outcome measures except anxiety and pain interference) to moderate (on anxiety and pain interference) at post-treatment and from small (on pain intensity and disability) to large (on pain interference) at follow-up. ACT showed significantly higher effects on depression and anxiety than MBSR and MBCT. Studies’ quality, attrition rate, type of pain and control group, did not moderate the effects of acceptance- and mindfulness-based interventions. Current acceptance- and mindfulness-based interventions, while not superior to traditional cognitive behavioral treatments, can be good alternatives.     

Lifestyle interventions in the treatment of childhood overweight: a meta-analytic review of randomized controlled trials.

CONTEXT: Evaluating the efficacy of pediatric weight loss treatments is critical. OBJECTIVE: This is the first meta-analysis of the efficacy of RCTs comparing pediatric lifestyle interventions to no-treatment or information/education-only controls. DATA SOURCES: Medline, PsycINFO, and Cochrane Controlled Trials Register. STUDY SELECTION: Fourteen RCTs targetting change in weight status were eligible, yielding 19 effect sizes. DATA EXTRACTION: Standardized coding was used to extract information on design, participant characteristics, interventions, and results. DATA SYNTHESIS: For trials with no-treatment controls, the mean effect size was 0.75 (k = 9, 95% confidence interval [CI] = 0.52-0.98) at end of treatment and 0.60 (k = 4, CI = 0.27-0.94) at follow-up. For trials with information/education-only controls, the mean ES was 0.48 (k = 4, CI = 0.13-0.82) at end of treatment and 0.91 (k = 2, CI = 0.32-1.50) at follow-up. No moderator effects were identified. CONCLUSIONS: Lifestyle interventions for pediatric overweight are efficacious in the short term with some evidence for extended persistence. Future research is required to identify moderators and mediators and to determine the optimal length and intensity of treatment required to produce enduring changes in weight status.     

The efficacy of cognitive-behavioral interventions for reducing anxiety sensitivity: a meta-analytic review

The present study meta-analytically reviewed the efficacy of cognitive-behavioral therapy (CBT) vs. control conditions in the reduction of anxiety sensitivity. A computerized search was conducted to indentify CBT outcome studies that included the Anxiety Sensitivity Index as a dependent variable. Of the 989 studies that were identified, 24 randomized-controlled trials with a total of 1851 participants met inclusion criteria and were included in the analysis. Data were extracted separately for treatment-seeking (16 studies) and at-risk (eight studies) samples. Results indicated large effect sizes for treatment-seeking samples, Hedges' g=1.40, SE=0.21, 95% CI: 1.00-1.81, p<0.001, and moderate to large effect sizes for at risk samples Hedges' g=0.74, SE=0.18, 95% CI: 0.39-1.08, p<0.001. Additionally, both the amount of therapist contact and control modality (waitlist vs. psychological control) moderated the effect sizes for treatment-seeking samples. Our review indicates that CBT is efficacious in reducing anxiety sensitivity. However, more research is needed to determine the mechanisms by which CBT exert its effects on anxiety sensitivity.     

Religious involvement and mortality: a meta-analytic review.

A meta-analysis of data from 42 independent samples examining the association of a measure of religious involvement and all-cause mortality is reported. Religious involvement was significantly associated with lower mortality (odds ratio = 1.29; 95% confidence interval: 1.20-1.39), indicating that people high in religious involvement were more likely to be alive at follow-up than people lower in religious involvement. Although the strength of the religious involvement-mortality association varied as a function of several moderator variables, the association of religious involvement and mortality was robust and on the order of magnitude that has come to be expected for psychosocial factors. Conclusions did not appear to be due to publication bias.     

Say something nice: A meta-analytic review of peer reporting interventions

Peer reporting interventions (i.e., Positive Peer Reporting and tootling) are commonly used peer-mediated interventions in schools. These interventions involve training students to make reports about peers' prosocial behaviors, whether in oral or written form. Although peer reporting interventions have been included in meta-analyses of group contingencies, this study is the first meta-analytic review of single-case research focusing exclusively on peer reporting interventions. The literature search and application of inclusion criteria yielded 21 studies examining the impact of a peer reporting intervention on student behavior compared to baseline conditions. All studies used single-case experimental designs including at least three demonstrations of an effect and at least three data points per phase. Several aspects of studies, participants, and interventions were coded. Log response ratios and Tau were calculated as effect size estimates. Effect size estimates were synthesized in a multi-level meta-analysis with random effects for (a) studies and (b) cases within studies. Overall results indicated peer reporting interventions had a non-zero and positive impact on student outcomes. This was also true when data were subset by outcome (i.e., disruptive behavior, academically engaged behavior, and social behavior). Results were suggestive of more between- than within-study variability. Moderator analyses were conducted to identify aspects of studies, participants, or peer reporting interventions associated with differential effectiveness. Moderator analyses suggested published studies were associated with higher effect sizes than unpublished studies (i.e., theses/dissertations). This meta-analysis suggests peer reporting interventions are effective in improving student behavior compared to baseline conditions. Implications and directions for future investigation are discussed.     

Psychological and physical well-being during unemployment: a meta-analytic study

The authors used theoretical models to organize the diverse unemployment literature, and meta-analytic techniques were used to examine the impact of unemployment on worker well-being across 104 empirical studies with 437 effect sizes. Unemployed individuals had lower psychological and physical well-being than did their employed counterparts. Unemployment duration and sample type (school leaver vs. mature unemployed) moderated the relationship between mental health and unemployment, but the current unemployment rate and the amount of unemployment benefits did not. Within unemployed samples, work-role centrality, coping resources (personal, social, financial, and time structure), cognitive appraisals, and coping strategies displayed stronger relationships with mental health than did human capital or demographic variables. The authors identify gaps in the literature and propose directions for future unemployment research.     

Efficacy of expectancy challenge interventions to reduce college student drinking: A meta-analytic review

Interventions challenging alcohol expectancies may lead to reductions in alcohol consumption. We conducted a meta-analysis to examine the efficacy of alcohol expectancy challenge (EC) interventions for college alcohol abuse prevention. Included were 14 studies (19 EC interventions) that measured alcohol expectancies and consumption, provided sufficient information to calculate effect sizes, and were available as of June 2010 (N = 1,415; M age = 20 years; 40% women; 88% White). Independent raters coded participant characteristics, design and methodological features, and intervention content, and calculated weighted mean effect sizes at first follow-up, using both fixed and random effects models. Compared with controls, EC participants reported lower positive alcohol expectancies, reduced their alcohol use, and reduced their frequency of heavy drinking (d+s ranged from 0.23 to 0.28). Within-group improvements in alcohol expectancies and consumption emerged for the EC group only; relative to their own baseline, EC participants reported lower positive alcohol expectancies, reduced their alcohol use, and reduced their frequency of heavy drinking (d+s ranged from 0.13 to 0.36). Supplemental analyses found improvements in specific alcohol expectancies (social, sexual, tension, and arousal) both between groups and within group. The short-term effects of EC interventions on college student drinking are not maintained at follow-ups greater than 4 weeks. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Leadership,creativity and innovation: a meta-analytic review

ABSTRACT

This paper reports the most comprehensive meta-analytic examination of the relationship between leadership and both followers’ creative and innovative performance. Specifically, we examined 13 leadership variables (transformational, transactional, ethical, humble, leader-member exchange, benevolent, authoritarian, entrepreneurial, authentic, servant, empowering, supportive, and destructive) using data from 266 studies. In addition to providing robustly estimated correlations, we explore two theoretically and pragmatically important issues: the relative importance of the different leadership constructs and moderators of the relationship between leadership and employee creativity and innovation. Regrading creative performance, authentic, empowering, and entrepreneurial leadership demonstrated the strongest relationships. For innovative performance, both transactional (contingent reward) and supportive leadership appear particularly relevant. The current study synthesizes an important, burgeoning, diverse body of research, and in doing so, generates nuanced evidence that can be used to guide theoretical advancements, improved research designs, and up-to-date policy recommendations regarding leading for creativity, and innovation.     

Attributional style in depression: a meta-analytic review

In this article we report meta-analyses of the relation of attributional styles to depression. In 104 studies involving nearly 15,000 subjects, several attributional patterns had reliable associations with depression scores. For negative events, attributions to internal, stable, and global causes had a reliable and significant association with depression. Studies in which the attribution factors of ability and luck were measured also showed a reliable association with depression. For positive events, attributions to external, unstable, and specific causes were associated with depression. Ability and luck attribution factors for positive events were also associated with depression. The relations for positive events, however, were weaker than the corresponding ones for negative events. In general, these patterns of relations were independent of a number of potential mediators suggested by authors in this literature, including the type of subject studied (psychiatric vs. college student), the type of event about which the attribution is made (real vs. simulated), the depression measure used, or the publication status of the research report. These conclusions are compared with those of other reviews. Implications for attributional models of depression are discussed.     

Eating disorder prevention programs: a meta-analytic review

This meta-analysis of eating disorder prevention programs found that intervention effects ranged from an absence of any effects to reductions in current and future eating pathology. Certain effects persisted as long as 2 years and were superior to minimal-intervention control conditions. Larger effects occurred for selected (vs. universal), interactive (vs. didactic), and multisession (vs. single session) programs; for programs offered solely to females and to participants over age 15; for programs without psychoeducational content; and for trials that used validated measures. The results identify promising prevention programs and delineate sample, format, and design features that are associated with larger effects, but they suggest the need for improved methodological rigor and statistical modeling of trials and enhanced theoretical rationale for interventions.     

A meta-analytic review of obesity prevention programs for children and adolescents: the skinny on interventions that work

This meta-analytic review summarizes obesity prevention programs and their effects and investigates participant, intervention, delivery, and design features associated with larger effects. A literature search identified 64 prevention programs seeking to produce weight gain prevention effects, of which 21% produced significant prevention effects that were typically pre- to post effects. Larger effects emerged for programs that targeted children and adolescents (vs. preadolescents) and females, programs that were relatively brief, programs that solely targeted weight control versus other health behaviors (e.g., smoking), programs evaluated in pilot trials, and programs wherein participants must have self-selected into the intervention. Other factors, including mandated improvements in diet and exercise, sedentary behavior reduction, delivery by trained interventionists, and parental involvement, were not associated with significantly larger effects.     

Temporal stability in the Rorschach method: a meta-analytic review

The temporal stabilities of the Rorschach method scoring systems were investigated. A comprehensive literature search was conducted to find all test-retest studies, both regular and from control samples in therapy evaluation studies. Meta-analyses were conducted for samples, individual entries, and variables in 36 samples. Separate analyses were made for 10 samples using the Comprehensive System (CS; Exner, 1993). The temporal stability was high, especially those obtained from regression model predictions. The CS consistently shows higher stability than other systems, whereas increasing retest intervals leads to decreasing stability. Shortcomings of the available studies are highlighted and discussed, and recommendations are given for design and methodology.     

Displaced aggression is alive and well: a meta-analytic review

Content analysis of 122 social psychology textbooks confirmed that displaced aggression received a surge of attention immediately following J. Dollard, L. W. Doob, N. E. Miller, O. H. Mowrer, and R. R. Sears (1939), but subsequent interest sharply declined. Contemporary texts give it little attention. By contrast, meta-analysis of the experimental literature confirms that it is a robust effect (mean effect size = +0.54). Additionally, moderator analyses showed that: (a) The more negative the setting in which the participant and target interacted, the greater the magnitude of displaced aggression; (b) in accord with N. E. Miller's (1948) stimulus generalization principle, the more similar the provocateur and target, the more displaced aggression; and (c) consistent with the contrast effect (L. Berkowitz & D. A. Knurek, 1969), the intensity of initial provocation is inversely related to the magnitude of displaced aggression.     

Stress, glucocorticoids, and memory: a meta-analytic review

Although a strong psychoneuroendocrine linkage exists between stress, glucocorticoids and memory, the relationship is not always straightforward. Eighty-eight effect sizes and 1642 participants from 28 studies were meta-analyzed for the effects of stress on memory performance and glucocorticoid activation. Analyses showed that stress was associated with glucocorticoid activation and declarative memory decline. In animal studies, predator stress affected memory performance more than physical stress. In human studies, males showed higher cortisol levels than females in response to stress. Further, the correlation between cortisol levels and memory deficits was stronger in studies using laboratory stressors than those examining long term effects of chronic exposure to rising basal levels of glucocorticoids and chronic life stressors. It was concluded that, although the relationship between stress, glucocorticoids, and memory loss was empirically supported, there were other factors, such as stress condition and gender, as well as individual differences within groups, that influenced the association between these variables, and warrant further examination.     

The brain basis of emotion: a meta-analytic review

Researchers have wondered how the brain creates emotions since the early days of psychological science. With a surge of studies in affective neuroscience in recent decades, scientists are poised to answer this question. In this target article, we present a meta-analytic summary of the neuroimaging literature on human emotion. We compare the locationist approach (i.e., the hypothesis that discrete emotion categories consistently and specifically correspond to distinct brain regions) with the psychological constructionist approach (i.e., the hypothesis that discrete emotion categories are constructed of more general brain networks not specific to those categories) to better understand the brain basis of emotion. We review both locationist and psychological constructionist hypotheses of brain-emotion correspondence and report meta-analytic findings bearing on these hypotheses. Overall, we found little evidence that discrete emotion categories can be consistently and specifically localized to distinct brain regions. Instead, we found evidence that is consistent with a psychological constructionist approach to the mind: A set of interacting brain regions commonly involved in basic psychological operations of both an emotional and non-emotional nature are active during emotion experience and perception across a range of discrete emotion categories.     

The sleeper effect in persuasion: a meta-analytic review

A meta-analysis of the available judgment and memory data on the sleeper effect in persuasion is presented. According to this effect, when people receive a communication associated with a discounting cue, such as a noncredible source, they are less persuaded immediately after exposure than they are later in time. Findings from this meta-analysis indicate that recipients of discounting cues were more persuaded over time when the message arguments and the cue had a strong initial impact. In addition, the increase in persuasion was stronger when recipients of discounting cues had higher ability or motivation to think about the message and received the discounting cue after the message. These results are discussed in light of classic and contemporary models of attitudes and persuasion.     

Deconstructing dependency in a five-factor world: a meta-analytic review

Meta-analysis of studies assessing the relation between interpersonal dependency test scores and five-factor model (FFM) domain scores revealed that dependency scores are positively correlated with FFM Neuroticism and Agreeableness scores and negatively correlated with FFM Extraversion, Openness, and Conscientiousness scores. The magnitudes of these correlations were all in the small-to-moderate range, and comparable score intercorrelations were obtained when participants' dependency levels were assessed by means of a trait dependency questionnaire, dependent personality disorder questionnaire, or dependent personality disorder interview. These findings have implications for researchers' efforts to deconstruct dependency into its basic trait elements and for the dimensional approaches to personality disorders being considered for future versions of the Diagnostic and Statistical Manual of Mental Disorders.