Rumination Across Depression, Anxiety, And Eating Disorders: A Meta-Analytic Review

Rumination is a repetitive thought process focused on symptoms, causes, and consequences of distress.

It’s a common feature in disorders like depression, anxiety, and eating disorders, potentially exacerbating symptoms and prolonging negative mood states.

Studying rumination is crucial because it may be a transdiagnostic factor underlying multiple psychological disorders.

Understanding its role can inform more effective assessment, diagnosis, and treatment approaches, potentially leading to improved outcomes across various mental health conditions.

Rickerby, N., Krug, I., Fuller-Tyszkiewicz, M., Forte, E., Davenport, R., Chayadi, E., & Kiropoulos, L. (2024). Rumination across depression, anxiety, and eating disorders in adults: A meta-analytic review. Clinical Psychology: Science and Practice, 31(2), 251–268. https://doi.org/10.1037/cps0000110

Key Points

• The primary methods of this meta-analysis included comparing rumination levels between patients with depression, anxiety, and eating disorders and healthy controls, as well as examining correlations between psychopathology severity and rumination.
• Factors like total rumination, brooding, and reflection were found to be significantly higher in patients with major depressive disorder (MDD), generalized anxiety disorder (GAD), social anxiety disorder (SAD), and anorexia nervosa (AN) compared to healthy controls.
• Significant medium to large correlations were found between psychopathology severity and rumination for MDD, GAD, SAD, and AN.
• This research has certain limitations such as the small number of studies available for some diagnostic groups, potential publication bias, and reliance on self-report measures of rumination.
• Rumination appears to be a transdiagnostic factor across depression, anxiety, and eating disorders, with implications for assessment, diagnosis, and treatment approaches.

Rationale

This meta-analysis aimed to examine rumination across depression, anxiety, and eating disorders in adults. The rationale for conducting this study was based on several key factors:

1. Previous research has identified rumination as a potential transdiagnostic process that may underlie multiple psychological disorders (McLaughlin & Nolen-Hoeksema, 2011; Nolen-Hoeksema & Watkins, 2011). However, most studies have focused on rumination in specific disorders rather than comparing across diagnostic categories.
2. While past meta-analyses have investigated rumination in depression and anxiety disorders (Aldao et al., 2010; Olatunji et al., 2013), or in eating disorders alone (Smith et al., 2018), there was a need for an updated and comprehensive review examining rumination across all three diagnostic categories.
3. Previous reviews often combined different anxiety disorders into a single group, potentially obscuring differences between specific diagnoses like GAD, SAD, and panic disorder. This study aimed to examine rumination in these anxiety disorders separately.
4. There was a lack of research on the specific components of rumination (brooding and reflection) across different disorders. This meta-analysis sought to address this gap by analyzing these subtypes when possible.
5. The most recent comprehensive review of rumination across depression, anxiety, and eating disorders (Aldao et al., 2010) only included studies up to 2008. An updated meta-analysis was needed to incorporate more recent research.
6. Previous reviews lacked quality assessments of included studies, limiting the ability to evaluate the strength of the evidence. This study aimed to conduct a formal quality appraisal.
7. There was a need to examine potential moderators of the relationship between rumination and psychopathology, such as age, gender, and clinical factors, which had shown mixed results in past research.

By addressing these gaps in the literature, this meta-analysis aimed to provide a more comprehensive and up-to-date understanding of rumination as a transdiagnostic process across depression, anxiety, and eating disorders.

Method

This meta-analytic review adhered to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. The project was registered on PROSPERO on July 31, 2020.

Search strategy and terms:

The initial search was conducted on July 29, 2020, using Medline, Embase, and PsychInfo databases.

Grey literature in the form of doctoral dissertations was searched on ProQuest Theses and Dissertations Global on August 4, 2020. A follow-up search was performed on all databases on December 1, 2021.

The search was limited to articles published after July 2008.

Medical Subject Headings (MeSH) terms for each disorder (depressive disorder, anxiety disorder, and eating disorder) were searched in combination with truncated terms for relevant specific disorders within the diagnostic categories set out in the DSM-5. The MeSH term “rumination” and associated truncated terms were also searched.

The full search strategies for each database are provided in the online supplementary materials.

Inclusion and exclusion criteria:

Inclusion criteria:

• Published and unpublished empirical articles and doctoral dissertations written in English
• At least one measure of rumination
• Participants aged 18-65 years
• Primary diagnosis of depression, anxiety, or eating disorder confirmed through clinical interview or provided by a health professional
• Cross-sectional and interventional studies with baseline measures of rumination, brooding, or reflection

Exclusion criteria:

• Participants younger than 18 or older than 65
• Self-report symptoms meeting clinical threshold without a formal diagnosis
• Primary diagnosis other than depression, anxiety, or eating disorder
• Sample comprised entirely of participants in remission
• Comorbid medical conditions
• Measures of repetitive negative thinking without a rumination subscale
• Only ecological momentary assessment (EMA) of rumination without baseline trait measure

Statistical measures:

Data analysis was conducted using the R package meta. Random effects modeling was used for the main analyses.

Standardized mean differences were used for group difference-based analyses, while r values (converted to z scores for analysis and back-transformed to r values for interpretation) were used for correlational analyses.

Heterogeneity was evaluated using Cochrane’s Q and quantified using I2. Metaregression was used to follow up on significant heterogeneity effects where data permitted.

Publication bias was assessed using funnel plots and Egger’s test.

Results

Group Differences in Rumination:

• Total rumination was significantly higher in MDD, GAD, SAD, and AN groups compared to healthy controls. No significant difference was found for panic disorder (PD).
• Brooding was significantly higher in MDD, GAD, and SAD groups compared to healthy controls.
• Reflection was significantly higher in MDD and SAD groups compared to healthy controls.
• The largest differences in effect sizes for brooding were observed in the SAD group, followed by MDD and GAD.
• For reflection, the largest differences were found in the MDD group, followed by SAD.

Correlations Between Psychopathology and Rumination:

• Significant medium to large correlations were found between symptom severity and total rumination in MDD, GAD, SAD, and AN groups.
• Strong positive correlations were observed between depressive symptoms and brooding in MDD, and between anxiety symptoms and brooding in SAD.
• A smaller positive correlation was found between depressive symptoms and reflection in MDD.
• Nonsignificant correlations were observed between anxiety symptoms and brooding in GAD and PD, and between anxiety symptoms and reflection in SAD.

Moderation Effects:

• Gender was the only significant moderator, with stronger associations between depressive symptoms and brooding observed in samples with a higher proportion of males in the MDD group.
• Age, presence of comorbidities, and medication use were not significant moderators for group differences or correlations in the MDD group.

Publication Bias:

• Egger’s test showed publication bias for MDD group comparisons with healthy controls on total rumination and brooding.
• No significant publication bias was found for other comparisons and correlations, but this may be due to the small number of studies in some analyses.

Quality Appraisal:

• Studies generally reported hypotheses, aims, objectives, main outcomes, and patient characteristics well.
• External validity and internal validity regarding bias were generally sufficient.
• Issues were identified with reporting of recruitment periods, adjustment for confounding factors, and statistical power.

Insight

This meta-analysis provides several key insights into the role of rumination across depression, anxiety, and eating disorders:

1. Transdiagnostic nature of rumination: The findings support the conceptualization of rumination as a transdiagnostic process, with elevated levels observed across MDD, GAD, SAD, and AN compared to healthy controls. This aligns with and extends previous theoretical models, such as the response-styles theory (Nolen-Hoeksema, 1991) and the transdiagnostic model (Nolen-Hoeksema & Watkins, 2011).
2. Disorder-specific patterns: While rumination was elevated across multiple disorders, the strength of associations varied. For example, the relationship between rumination and psychopathology was strongest for MDD and SAD, followed by GAD and AN. This suggests that while rumination is indeed transdiagnostic, its role may be more pronounced in certain disorders.
3. Importance of examining specific anxiety disorders: By analyzing GAD, SAD, and PD separately, the study revealed important differences that may have been obscured in previous research combining anxiety disorders. For instance, rumination was not significantly elevated in PD compared to controls, contrasting with findings for GAD and SAD.
4. Differential roles of brooding and reflection: The analysis of rumination subtypes provided novel insights. Brooding showed stronger associations with psychopathology than reflection, particularly in SAD. This extends previous findings and suggests that certain components of rumination may be more closely linked to specific disorders.
5. Gender as a potential moderator: The finding that associations between depressive symptoms and brooding were stronger in samples with more males challenges some previous research and highlights the need for further investigation into gender differences in rumination.
6. Limited research in eating disorders: The study highlighted a significant gap in research on rumination in eating disorders, particularly for specific diagnoses like bulimia nervosa and binge eating disorder.

These findings extend previous research by providing a more nuanced understanding of rumination across multiple disorders and highlighting areas for future investigation.

Further research is needed to:

1. Examine rumination in larger samples of patients with specific anxiety and eating disorder diagnoses.
2. Investigate the causal relationships between rumination and psychopathology using longitudinal designs.
3. Explore the efficacy of rumination-focused treatments across different disorders.
4. Examine potential neurobiological underpinnings of rumination as a transdiagnostic process.
5. Investigate how rumination interacts with other transdiagnostic factors (e.g., perfectionism, intolerance of uncertainty) across disorders.

Strengths

The study had several methodological strengths:

1. Comprehensive scope: The meta-analysis examined rumination across multiple disorders, providing a broader perspective than previous reviews focused on single diagnostic categories.
2. Specific diagnostic groups: By analyzing specific anxiety disorders separately, the study revealed important differences that might have been overlooked in previous research.
3. Analysis of rumination subtypes: The inclusion of brooding and reflection as separate constructs provided more nuanced insights into the role of rumination across disorders.
4. Quality assessment: The study included a formal quality appraisal of included studies, which was lacking in previous reviews.
5. Up-to-date literature: The analysis included studies published up to December 2021, providing a current synthesis of the field.
6. Adherence to guidelines: The study followed PRISMA guidelines and was pre-registered, enhancing its methodological rigor and transparency.
7. Examination of moderators: The analysis attempted to investigate potential moderators of the relationship between rumination and psychopathology, addressing an important gap in the literature.

Limitations

Several limitations should be considered when interpreting the results:

1. Small sample sizes: For some diagnostic groups (e.g., PD, AN) and analyses of brooding and reflection, the number of available studies was small, limiting the reliability and generalizability of findings.
2. Reliance on self-report measures: The assessment of rumination was based on self-report questionnaires, which may be subject to bias and may not fully capture the complexity of ruminative processes.
3. Cross-sectional design: Most included studies were cross-sectional, limiting the ability to draw causal conclusions about the relationship between rumination and psychopathology.
4. Publication bias: Significant publication bias was detected for some analyses, particularly those involving MDD, which may have inflated effect sizes.
5. Limited data on moderators: Insufficient data were available to thoroughly examine potential moderators across all diagnostic groups, restricting analyses to the MDD group for most moderators.
6. Exclusion of remitted patients: By focusing only on current diagnoses, the study may have missed important information about the role of rumination in the course of disorders.
7. Age restrictions: The exclusion of studies with participants under 18 or over 65 limits the generalizability of findings to these age groups.
8. Lack of non-Western samples: Most included studies were conducted in Western countries, potentially limiting the cultural generalizability of the findings.

These limitations highlight the need for further research with larger, more diverse samples, longitudinal designs, and alternative methods of assessing rumination.

Implications

The findings of this meta-analysis have several important implications for clinical psychology practice and research:

1. Assessment and diagnosis: The strong associations between rumination and multiple disorders suggest that assessing rumination could be valuable in the diagnostic process. Clinicians should consider incorporating measures of rumination, particularly brooding, when evaluating patients with depressive, anxiety, and eating disorders.
2. Treatment approaches: The transdiagnostic nature of rumination supports the development and use of treatment approaches that specifically target ruminative processes across disorders. Rumination-focused cognitive-behavioral therapy (RFCBT) and other interventions targeting repetitive negative thinking may be beneficial for multiple conditions.
3. Personalized interventions: The variation in the strength of associations between rumination and different disorders suggests that the emphasis on rumination in treatment may need to be tailored to specific diagnoses. For example, interventions for SAD and MDD may need to focus more heavily on reducing rumination compared to those for PD.
4. Focus on brooding: The stronger associations found for brooding compared to reflection suggest that treatments should particularly target this maladaptive component of rumination.
5. Gender considerations: The finding that associations between depressive symptoms and brooding were stronger in samples with more males highlights the need for clinicians to be aware of potential gender differences in ruminative processes.
6. Transdiagnostic research: The results support the value of transdiagnostic approaches in psychopathology research and suggest that future studies should continue to examine processes like rumination across multiple disorders.
7. Eating disorder focus: The limited research available on rumination in eating disorders, particularly for specific diagnoses like bulimia nervosa and binge eating disorder, indicates a need for more studies in this area.
8. Longitudinal research: To better understand the causal relationships between rumination and psychopathology, more longitudinal studies are needed. This could inform prevention efforts by identifying whether rumination precedes the onset of disorders.
9. Measurement development: The limitations of self-report measures suggest a need for developing and validating alternative methods of assessing rumination, such as behavioral tasks or ecological momentary assessment.
10. Neurobiological research: The consistent finding of elevated rumination across multiple disorders suggests that investigating the neural correlates of rumination as a transdiagnostic process could be a fruitful area for future research.

These implications underscore the importance of considering rumination in both clinical practice and research across a range of psychological disorders.

By targeting rumination as a transdiagnostic process, there is potential to improve assessment, treatment, and prevention efforts for multiple conditions.

References

Primary reference

Rickerby, N., Krug, I., Fuller-Tyszkiewicz, M., Forte, E., Davenport, R., Chayadi, E., & Kiropoulos, L. (2024). Rumination across depression, anxiety, and eating disorders in adults: A meta-analytic review. Clinical Psychology: Science and Practice, 31(2), 251–268. https://doi.org/10.1037/cps0000110

Other references

Aldao, A., Nolen-Hoeksema, S., & Schweizer, S. (2010). Emotion-regulation strategies across psychopathology: A meta-analytic review. Clinical psychology review, 30(2), 217-237. https://doi.org/10.1016/j.cpr.2009.11.004

McLaughlin, K. A., & Nolen-Hoeksema, S. (2011). Rumination as a transdiagnostic factor in depression and anxiety. Behaviour research and therapy, 49(3), 186-193. https://doi.org/10.1016/j.brat.2010.12.006

Nolen-Hoeksema, S. (1991). Responses to depression and their effects on the duration of depressive episodes. Journal of abnormal psychology, 100(4), 569. https://doi.org/10.1037/0021-843X.100.4.569

Nolen-Hoeksema, S., & Watkins, E. R. (2011). A heuristic for developing transdiagnostic models of psychopathology: Explaining multifinality and divergent trajectories. Perspectives on psychological science, 6(6), 589-609. https://doi.org/10.1177/1745691611419672

Olatunji, B. O., Naragon-Gainey, K., & Wolitzky-Taylor, K. B. (2013). Specificity of rumination in anxiety and depression: A multimodal meta‐analysis. Clinical Psychology: Science and Practice, 20(3), 225. https://doi.org/10.1037/h0101719

Smith, K. E., Mason, T. B., & Lavender, J. M. (2018). Rumination and eating disorder psychopathology: A meta-analysis. Clinical psychology review, 61, 9-23. https://doi.org/10.1016/j.cpr.2018.03.004

Keep Learning

1. How might the finding that rumination is elevated across multiple disorders inform the development of transdiagnostic treatment approaches?
2. What are the potential implications of the stronger associations found for brooding compared to reflection? How might this influence cognitive-behavioral interventions for depression and anxiety?
3. Given the limitations of self-report measures, what alternative methods could be developed to assess rumination more objectively or ecologically?
4. How might the observed gender differences in the relationship between depressive symptoms and brooding inform our understanding of gender disparities in depression rates?
5. Considering the limited research on rumination in eating disorders, what specific research questions should be prioritized to advance our understanding in this area?
6. How might the neuroscience of rumination as a transdiagnostic process inform our understanding of the shared neural mechanisms underlying different psychological disorders?
7. Given the cross-sectional nature of most included studies, how could future longitudinal research better elucidate the causal relationships between rumination and psychopathology?
8. How might cultural factors influence ruminative processes across different disorders? How can future research address the limited representation of non-Western samples in this field?