Anxiety, Affect, Self-Esteem, and Stress: Mediation and Moderation Effects on Depression
and Stress: Mediation and Moderation Effects on Depression. PLoS
ONE 8(9): e73265. doi:10.1371/journal.pone.0073265
Anxiety, Affect, Self-Esteem, and Stress: Mediation and Moderation Effects on Depression
Ali Al Nima 0
Patricia Rosenberg 0
Trevor Archer 0
Danilo Garcia 0
Ben J. Harrison, The University of Melbourne, Australia
0 1 Department of Psychology, University of Gothenburg , Gothenburg, Sweden, 2 Network for Empowerment and Well-Being , University of Gothenburg , Gothenburg , Sweden , 3 Department of Psychology, Education and Sport Science, Linneaus University , Kalmar, Sweden, 4 Center for Ethics, Law, and Mental Health (CELAM) , University of Gothenburg , Gothenburg , Sweden , 5 Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
Background: Mediation analysis investigates whether a variable (i.e., mediator) changes in regard to an independent variable, in turn, affecting a dependent variable. Moderation analysis, on the other hand, investigates whether the statistical interaction between independent variables predict a dependent variable. Although this difference between these two types of analysis is explicit in current literature, there is still confusion with regard to the mediating and moderating effects of different variables on depression. The purpose of this study was to assess the mediating and moderating effects of anxiety, stress, positive affect, and negative affect on depression. Methods: Two hundred and two university students (males = 93, females = 113) completed questionnaires assessing anxiety, stress, self-esteem, positive and negative affect, and depression. Mediation and moderation analyses were conducted using techniques based on standard multiple regression and hierarchical regression analyses. Main Findings: The results indicated that (i) anxiety partially mediated the effects of both stress and self-esteem upon depression, (ii) that stress partially mediated the effects of anxiety and positive affect upon depression, (iii) that stress completely mediated the effects of self-esteem on depression, and (iv) that there was a significant interaction between stress and negative affect, and between positive affect and negative affect upon depression. Conclusion: The study highlights different research questions that can be investigated depending on whether researchers decide to use the same variables as mediators and/or moderators.
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Mediation refers to the covariance relationships among three
variables: an independent variable (1), an assumed mediating
variable (2), and a dependent variable (3). Mediation analysis
investigates whether the mediating variable accounts for a
significant amount of the shared variance between the
independent and the dependent variablesthe mediator changes in
regard to the independent variable, in turn, affecting the
dependent one [1,2]. On the other hand, moderation refers to
the examination of the statistical interaction between
independent variables in predicting a dependent variable [1,3]. In
contrast to the mediator, the moderator is not expected to be
correlated with both the independent and the dependent
variableBaron and Kenny [1] actually recommend that it is
best if the moderator is not correlated with the independent
variable and if the moderator is relatively stable, like a
demographic variable (e.g., gender, socio-economic status) or a
personality trait (e.g., affectivity).
Although both types of analysis lead to different conclusions [3]
and the distinction between statistical procedures is part of the
current literature [2], there is still confusion about the use of
moderation and mediation analyses using data pertaining to the
prediction of depression. There are, for example, contradictions
among studies that investigate mediating and moderating effects
of anxiety, stress, self-esteem, and affect on depression.
Depression, anxiety and stress are suggested to influence individuals
social relations and activities, work, and studies, as well as
compromising decision-making and coping strategies [4,5,6].
Successfully coping with anxiety, depressiveness, and stressful
situations may contribute to high levels of self-esteem and
selfconfidence, in addition increasing well-being, and psychological
and physical health [6]. Thus, it is important to disentangle how
these variables are related to each other. However, while some
researchers perform mediation analysis with some of the variables
mentioned here, other researchers conduct moderation analysis
with the same variables. Seldom are both moderation and
mediation performed on the same dataset. Before disentangling
mediation and moderation effects on depression in the current
literature, we briefly present the methodology behind the analysis
performed in this study.
Note: * p,.05, ** p,.01.
doi:10.1371/journal.pone.0073265.t001
Mediation and moderation
Baron and Kenny [1] postulated several criteria for the analysis
of a media (...truncated)