Hypotheses involving mediation are common in the behavioral sciences. Mediation exists when a predictor affects a dependent variable indirectly through at least one intervening variable, or mediator. Methods to assess mediation involving multiple simultaneous mediators have received little attention in the methodological literature despite a clear need. We provide an overview of simple and multiple mediation and explore three approaches that can be used to investigate indirect processes, as well as methods for contrasting two or more mediators within a single model. We present an illustrative example, assessing and contrasting potential mediators of the relationship between the helpfulness of socialization agents and job satisfaction. We also provide SAS and SPSS macros, as well as Mplus and LISREL syntax, to facilitate the use of these methods in applications.

https://link.springer.com/content/pdf/10.3758/BRM.40.3.879.pdf

Asymptotic and resampling strategies for assessing and comparing indirect effects in multiple mediator models

Reliability coefficients often take the form of intraclass correlation coefficients. In this article, guidelines are given for choosing among six different forms of the intraclass correlation for reliability studies in which n target are rated by k judges. Relevant to the choice of the coefficient are the appropriate statistical model for the reliability and the application to be made of the reliability results. Confidence intervals for each of the forms are reviewed.

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Intraclass correlations: uses in assessing rater reliability.

The Mini-International Neuropsychiatric Interview (M.I.N.I.) is a short structured diagnostic interview, developed jointly by psychiatrists and clinicians in the United States and Europe, for DSM-IV and ICD-10 psychiatric disorders. With an administration time of approximately 15 minutes, it was designed to meet the need for a short but accurate structured psychiatric interview for multicenter clinical trials and epidemiology studies and to be used as a first step in outcome tracking in nonresearch clinical settings. The authors describe the development of the M.I.N.I. and its family of interviews: the M.I.N.I.-Screen, the M.I.N.I.-Plus, and the M.I.N.I.-Kid. They report on validation of the M.I.N.I. in relation to the Structured Clinical Interview for DSM-III-R, Patient Version, the Composite International Diagnostic Interview, and expert professional opinion, and they comment on potential applications for this interview.

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The Mini-International Neuropsychiatric Interview (M.I.N.I.) : The development and validation of a Structured Diagnostic Psychiatric Interview for DSM-IV and ICD-10

Assessing the quality of reports of randomized clinical trials : is blinding necessary?

Researchers often conduct mediation analysis in order to indirectly assess the effect of a proposed cause on some outcome through a proposed mediator. The utility of mediation analysis stems from its ability to go beyond the merely descriptive to a more functional understanding of the relationships among variables. A necessary component of mediation is a statistically and practically significant indirect effect. Although mediation hypotheses are frequently explored in psychological research, formal significance tests of indirect effects are rarely conducted. After a brief overview of mediation, we argue the importance of directly testing the significance of indirect effects and provide SPSS and SAS macros that facilitate estimation of the indirect effect with a normal theory approach and a bootstrap approach to obtaining confidence intervals, as well as the traditional approach advocated by Baron and Kenny (1986). We hope that this discussion and the macros will enhance the frequency of formal mediation tests in the psychology literature. Electronic copies of these macros may be downloaded from the Psychonomic Society's Web archive at www.psychonomic.org/archive/.

/pdf/spss-and-sas-procedures-for-estimating-indirect-effects-in-51fap1x8sl.pdf

SPSS and SAS procedures for estimating indirect effects in simple mediation models.

Mediation is said to occur when a causal effect of some variable X on an outcome Y is explained by some intervening variable M. The authors recommend that with small to moderate samples, bootstrap methods (B. Efron & R. Tibshirani, 1993) be used to assess mediation. Bootstrap tests are powerful because they detect that the sampling distribution of the mediated effect is skewed away from 0. They argue that R. M. Baron and D. A. Kenny's (1986) recommendation of first testing the X --> Y association for statistical significance should not be a requirement when there is a priori belief that the effect size is small or suppression is a possibility. Empirical examples and computer setups for bootstrap analyses are provided.

/pdf/mediation-in-experimental-and-nonexperimental-studies-new-36pi5vkg4y.pdf

Mediation in experimental and nonexperimental studies: New procedures and recommendations.

Critics of labeling theory vigorously dispute Scheff's (1966) provocative etiological hypothesis and downplay the importance of factors such as stigma and stereotyping. We propose a modified labeling perspective which claims that even if labeling does not directly produce mental disorder, it can lead to negative outcomes. Our approach asserts that socialization leads individuals to develop a set of beliefs about how most people treat mental patients. When individuals enter treatment, these beliefs take on new meaning. The more patients believe that they will be devalued and discriminated against, the more they feel threatened by interacting with others. They may keep their treatment a secret, try to educate others about their situation, or withdraw from social contacts that they perceive as potentially rejecting. Such strategies can lead to negative consequences for social support networks, jobs, and self-esteem. We test this modified labeling perspective using samples of patients and untreated community residents, and find that both believe that "most people" will reject mental patients. Additionally, patients endorse strategies of secrecy, withdrawal, and education to cope with the threat they perceive. Finally, patients' social support networks are affected by the extent to which they fear rejection and by the coping responses they adopt to deal with their stigmatized status.

https://www.jstor.org/stable/pdfplus/2095613.pdf

A modified labeling theory approach to mental disorders : an empirical assessment

Are inverse relations between psychiatric disorders and socioeconomic status due more to social causation (adversity and stress) or social selection (downward mobility of genetically predisposed)? This classical epidemiological issue is tested by focusing on ethnic status in relation to socioeconomic status. Ethnic status cannot be an effect of disorder because it is present at birth whereas socioeconomic status depends on educational and occupational attainment. A birth cohort sample of 4914 young, Israel-born adults of European and North African background was selected from the country's population register, screened, and diagnosed by psychiatrists. Results indicate that social selection may be more important for schizophrenia and that social causation may be more important for depression in women and for antisocial personality and substance use disorders in men.

https://science.sciencemag.org/content/sci/255/5047/946.full.pdf

Socioeconomic status and psychiatric disorders: The causation-selection issue.

Psychiatric research has benefited from attention to measurement theories of reliability, and reliability/agreement statistics for psychopathology ratings and diagnoses are regularly reported in empirical reports. Nevertheless, there are still controversies regarding how reliability should be measured, and the amount of resources that should be spent on studying measurement quality in research programs. These issues are discussed in the context of recent theoretical and technical contributions to the statistical analysis of reliability. Special attention is paid to statistical studies published since Kraemer's 1992 review of reliability methods in this journal.

Patrick E. Shrout

Papers

Intraclass correlations: uses in assessing rater reliability.

Mediation in experimental and nonexperimental studies: New procedures and recommendations.

A modified labeling theory approach to mental disorders : an empirical assessment

Socioeconomic status and psychiatric disorders: The causation-selection issue.

Measurement reliability and agreement in psychiatry