Where oh where are the specific ingredients? A meta-analysis of component studies in counseling and psychotherapy.

Component studies, which involve comparisons between a treatment package and the treatment package without a theoretically important component or the treatment package with an added component, use experimental designs to test whether the component is necessary to produce therapeutic benefit. A meta-analysis was conducted on 27 component studies culled from the literature. It was found that the effect size for the difference between a package with and without the critical components was not significantly different from zero, indicating that theoretically purported important components are not responsible for therapeutic benefits. Moreover, the effect sizes were homogeneous, which suggests that there were no important variables moderating effect sizes. The results cast doubt on the specificity of psychological treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A meta-analytic review of the effectiveness of inpatient group psychotherapy.

The effectiveness of inpatient group therapy was estimated in a meta-analysis of 24 controlled and 46 studies with pre-post-measures published between 1980 and 2004. Diagnosis, theoretical orientation and the role of the group in the particular treatment setting were used to examine differential effectiveness. Beneficial effects were found for inpatient group therapy in controlled studies (d = 0.31) as well as in the studies with pre-post-data (d = 0.59). Differences in the homogeneity of patient improvement effect sizes were found across different diagnostic categories. Furthermore, greater improvement was exhibited in mood disorder patients when compared to mixed, psychosomatic, post traumatic stress disorder (PTSD), and schizophrenic patients replicating recent findings from meta-analyses of outpatient group treatment. A comparison between controlled studies and pre-post-measure studies indicated no improvement for waitlist patients which contradicts previous reports. Implications for therapy and future research are discussed within the context of methodical considerations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Injury severity and outcome: A meta-analysis of prospective studies on TBI outcome.

Objective: The recent movement to apply evidenced-based approaches to medical and rehabilitation care has increased the importance of approximating outcomes as early in the recovery process as possible. The relationship between injury severity and outcome following traumatic brain injury (TBI), however, has remained unclear due to the variety of predictor and criterion variables used throughout the literature. Method: A meta-analysis of eligible prospective studies that assessed the bivariate association between injury severity and outcome at 1-year postinjury was conducted. Results: Twenty-six studies met the inclusion criteria (total N = 21,050 patients). Injury severity was a significant predictor of outcome at 1-year postinjury (r = .257). Homogeneity testing by means of the Q test, Q(n), indicated that injury severity measurement, Q(68) = 1140.76, p     

The effectiveness of psychodramatic techniques: A meta-analysis.

Questions concerning the scientific basis of the clinical application of psychodramatic techniques have been raised primarily because of the infrequency of research publications that validate the clinical observations. A meta-analysis conducted on the basis of 25 experimentally designed studies showed an overall effect size that points to a large size improvement effect similar to or better than that commonly reported for group psychotherapy in general. The techniques of role reversal and doubling emerged as the most effective interventions. Of the 4 techniques investigated, 3 were significantly different from each other. There was no difference between the techniques' effectiveness when used with clinical versus student populations or between their use in single versus multiple sessions. The meaning of the findings is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychotherapy and the placebo effect.

The theoretical and methodological problems involved in studies concerned with the "placebo effect" are presented. There is a need for more theoretically oriented research and for "a greater emphasis upon control factors and other methodological considerations." Future research should be directed towards a further understanding of the influence of non-specific factors in psychotherapy. 39 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in left-handedness: A meta-analysis of 144 studies.

Human handedness, a marker for language lateralization in the brain, continues to attract great research interest. A widely reported but not universal finding is a greater male tendency toward left-handedness. Here the authors present a meta-analysis of k = 144 studies, totaling N = 1,787,629 participants, the results of which demonstrate that the sex difference is both significant and robust. The overall best estimate for the male to female odds ratio was 1.23 (95% confidence interval = 1.19, 1.27). The widespread observation of this sex difference is consistent with it being related to innate characteristics of sexual differentiation, and its observed magnitude places an important constraint on current theories of handedness. In addition, the size of the sex difference was significantly moderated by the way in which handedness was assessed (by writing hand or by other means), the location of testing, and the year of publication of the study, implicating additional influences on its development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychotherapy for depression in adults: A meta-analysis of comparative outcome studies.

Although the subject has been debated and examined for more than 3 decades, it is still not clear whether all psychotherapies are equally efficacious. The authors conducted 7 meta-analyses (with a total of 53 studies) in which 7 major types of psychological treatment for mild to moderate adult depression (cognitive-behavior therapy, nondirective supportive treatment, behavioral activation treatment, psychodynamic treatment, problem-solving therapy, interpersonal psychotherapy, and social skills training) were directly compared with other psychological treatments. Each major type of treatment had been examined in at least 5 randomized comparative trials. There was no indication that 1 of the treatments was more or less efficacious, with the exception of interpersonal psychotherapy (which was somewhat more efficacious; d = 0.20) and nondirective supportive treatment (which was somewhat less efficacious than the other treatments; d = -0.13). The drop-out rate was significantly higher in cognitive-behavior therapy than in the other therapies, whereas it was significantly lower in problem-solving therapy. This study suggests that there are no large differences in efficacy between the major psychotherapies for mild to moderate depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Organizational culture and organizational effectiveness: A meta-analytic investigation of the competing values framework's theoretical suppositions.

[Correction Notice: An erratum for this article was reported in Vol 96(4) of Journal of Applied Psychology (see record 2011-06260-001). In this article the supplemental materials doi was incorrect. The correct doi is: http://dx.doi.org/10.1037/a0021987.supp All versions of this article have been corrected.] We apply Quinn and Rohrbaugh's (1983) competing values framework (CVF) as an organizing taxonomy to meta-analytically test hypotheses about the relationship between 3 culture types and 3 major indices of organizational effectiveness (employee attitudes, operational performance [i.e., innovation and product and service quality], and financial performance). The paper also tests theoretical suppositions undergirding the CVF by investigating the framework's nomological validity and proposed internal structure (i.e., interrelationships among culture types). Results based on data from 84 empirical studies with 94 independent samples indicate that clan, adhocracy, and market cultures are differentially and positively associated with the effectiveness criteria, though not always as hypothesized. The findings provide mixed support for the CVF's nomological validity and fail to support aspects of the CVF's proposed internal structure. We propose an alternative theoretical approach to the CVF and delineate directions for future research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A note on the judgment of speaker effectiveness.

Ratings of the effectiveness of the speaker at each of 14 meetings (445 participants, some attending more than 1 meeting) on an 8-item rating scale showed that a simple rating procedure can yield useful discrimination as to the excellence of public-speaker addressed meetings. However, this discrimination is primarily on a general or overall factor, with little evidence of differentiation among such elements as the speaker's qualifications or ability, topic coverage, personal gain from meeting, or satisfaction of expectations. Ratings of "timeliness of topic" alone tended to be somewhat independent of the evaluation of the meeting itself. Ratings of the effectiveness of the speaker were not significantly correlated with attendance at the meetings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Statistical significance testing and clinical effectiveness studies.

Effectiveness studies, by definition, must reflect patient and treatment variables that exist in the real world of practice. This includes identifying the covariates that contribute to both positive and negative outcomes. The use of clinically significant change and reliable change indices is reviewed to demonstrate that patient changes can be made on the basis of normative comparisons, using outcome relevant variables that reflect the diversity of problems that are of concern to our clients. Therefore, neither agreement on a single outcome index nor plotting the entire outcome frequency distributions of the comparison group, as called for by Krause (see record 2011-19228-002), is required. Various methods currently exist and are used to address the limitations Krause cites with respect to randomized trials, outcome relevant covariates, file-drawer effects, and so forth. The identification and prediction of an individual's treatment response can be done in treatment as usual studies, where outcome relevant covariates have not been controlled, by studying change at the individual level. By studying such individuals and their combined continuums of treatment response, we can then identify clinically relevant outcome variables and alter the course of treatment accordingly. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effects of chronic exercise on feelings of energy and fatigue: A quantitative synthesis.

The authors investigated the effect of chronic exercise on feelings of energy and fatigue using meta-analytic techniques. Chronic exercise increased feelings of energy and lessened feelings of fatigue compared with control conditions by a mean effect delta of 0.37. The effect varied according to the presence or absence of a placebo control or whether chronic exercise was completed alone or in combination with an additional therapy. Investigations that used a placebo control and examined chronic exercise alone found no effect of chronic exercise on feelings of energy and fatigue. Certain placebo controls may increase feelings of energy and lessen feelings of fatigue when used with older adults or people with psychological distress. The results highlight the need for research identifying the most useful control conditions for accurately interpreting mental health outcome data obtained in chronic exercise investigations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of the media in body image concerns among women: A meta-analysis of experimental and correlational studies.

Research suggests that exposure to mass media depicting the thin-ideal body may be linked to body image disturbance in women. This meta-analysis examined experimental and correlational studies testing the links between media exposure to women's body dissatisfaction, internalization of the thin ideal, and eating behaviors and beliefs with a sample of 77 studies that yielded 141 effect sizes. The mean effect sizes were small to moderate (ds = -.28, -.39, and -.30, respectively). Effects for some outcome variables were moderated by publication year and study design. The findings support the notion that exposure to media images depicting the thin-ideal body is related to body image concerns for women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender differences in temperament: A meta-analysis.

The authors used meta-analytical techniques to estimate the magnitude of gender differences in mean level and variability of 35 dimensions and 3 factors of temperament in children ages 3 months to 13 years. Effortful control showed a large difference favoring girls and the dimensions within that factor (e.g., inhibitory control: d = -.41, perceptual sensitivity: d = -0.38) showed moderate gender differences favoring girls, consistent with boys' greater incidence of externalizing disorders. Surgency showed a difference favoring boys, as did some of the dimensions within that factor (e.g., activity: d = 0.33, high-intensity pleasure: d = 0.30), consistent with boys' greater involvement in active rough-and-tumble play. Negative affectivity showed negligible gender differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patterns of mean-level change in personality traits across the life course: A meta-analysis of longitudinal studies.

The present study used meta-analytic techniques (number of samples = 92) to determine the patterns of mean-level change in personality traits across the life course. Results showed that people increase in measures of social dominance (a facet of extraversion), conscientiousness, and emotional stability, especially in young adulthood (age 20 to 40). In contrast, people increase on measures of social vitality (a 2nd facet of extraversion) and openness in adolescence but then decrease in both of these domains in old age. Agreeableness changed only in old age. Of the 6 trait categories, 4 demonstrated significant change in middle and old age. Gender and attrition had minimal effects on change, whereas longer studies and studies based on younger cohorts showed greater change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The causal relation between job attitudes and performance: A meta-analysis of panel studies.

Do job attitudes cause performance, or is it the other way around? To answer this perennial question, the author conducted meta-analytic regression analyses on 16 studies that had repeatedly measured performance and job attitudes (i.e., job satisfaction or organizational commitment). The effect of job attitudes on subsequent performance, with baseline performance controlled, was weak but statistically significant (β = .06). The effect was slightly stronger for commitment than for satisfaction and depended negatively on time lag. Effects of performance on subsequent job attitudes were elusive (β = .00 across all studies), which suggests that job attitudes are more likely to influence performance than vice versa. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effectiveness of a marijuana expectancy manipulation: Piloting the balanced-placebo design for marijuana.

Although alcohol and nicotine administration studies have demonstrated that manipulating subjects’ expectancies regarding drug content affects drug response, research with marijuana has not adequately studied drug expectancy effects. The present pilot study was the first to evaluate the credibility and effect of expectancy manipulation on subjective measures and smoking patterns using a marijuana administration balanced-placebo design (BPD). In a 2 × 2 instructional set (told delta-9-tetrahydrocannabinol [THC] vs. told no THC) by drug (smoked marijuana with 2.8% THC vs. placebo) between-subjects design, the authors examined the effect of marijuana expectancy manipulation and the pharmacologic effect on affective and physiologic measures, cigarette ratings, and smoking behavior with 20 marijuana smokers (mean age = 20 years; 25% female). Large main effects of expectancy were found on ratings of cigarette potency, strength, taste, smell, and satisfaction, and observed smoking behavior. Pharmacologic effects were particularly evident for self-reported physical reactions to marijuana and cigarette potency and satisfaction ratings. This study demonstrated the feasibility of the BPD research with marijuana and yielded promising results for future studies examining the independent and combined effects of marijuana pharmacology and expectancies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic and environmental influences on antisocial behavior: A meta-analysis of twin and adoption studies.

A meta-analysis of 51 twin and adoption studies was conducted to estimate the magnitude of genetic and environmental influences on antisocial behavior. The best fitting model included moderate proportions of variance due to additive genetic influences (.32), nonadditive genetic influences (.09), shared environmental influences (.16), and nonshared environmental influences (.43). The magnitude of familial influences (i.e., both genetic and shared environmental influences) was lower in parent-offspring adoption studies than in both twin studies and sibling adoption studies. Operationalization, assessment method, zygosity determination method, and age were significant moderators of the magnitude of genetic and environmental influences on antisocial behavior, but there were no significant differences in the magnitude of genetic and environmental influences for males and females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The accuracy of recidivism risk assessments for sexual offenders: A meta-analysis of 118 prediction studies.

This review compared the accuracy of various approaches to the prediction of recidivism among sexual offenders. On the basis of a meta-analysis of 536 findings drawn from 118 distinct samples (45,398 sexual offenders, 16 countries), empirically derived actuarial measures were more accurate than unstructured professional judgment for all outcomes (sexual, violent, or any recidivism). The accuracy of structured professional judgment was intermediate between the accuracy found for the actuarial measures and for unstructured professional judgment. The effect sizes for the actuarial measures were moderate to large by conventional standards (average d values of 0.67–0.97); however, the utility of the actuarial measures will vary according to the referral question and samples assessed. Further research should identify the psychologically meaningfully factors that contribute to risk for reoffending. (PsycINFO Database Record (c) 2010 APA, all rights reserved)