Leiden University Student Repository

Argeșeanu, Gabriela (2025)

Changes in Defensive Functioning During Psychotherapy: A Meta-Analysis of Observer-Rated and Self-Reported Perspectives

Master thesis | Psychology (MSc)

In this meta-analysis, changes in defense mechanisms were studied during diverse psychodynamic and cognitive-behavioural interventions in adult clinical populations. The primary aim was to determine whether overall defensive functioning (ODF) improves over the course of psychotherapeutic treatments. A search of studies published in English between 1991 and 2024 was conducted using PubMed. Eligible studies included those that assessed ODF before and after treatment using either the Defense Mechanism Rating Scale (DMRS) or the Defense Style Questionnaire (DSQ). Studies with very small or non-clinical samples were eliminated. The final synthesis included 14 effect sizes from 12 studies. A multilayered aggregated calculation was applied using R (version 4.4.3) with the readxl and metafor packages. ODF changes obtained d = 0.56, 95% CI [0.34, 0.78], z = 5.07, p < .001. Findings indicated a significant moderate effect in ODF changes during psychotherapies. Evidence is primarily limited by...Show moreIn this meta-analysis, changes in defense mechanisms were studied during diverse psychodynamic and cognitive-behavioural interventions in adult clinical populations. The primary aim was to determine whether overall defensive functioning (ODF) improves over the course of psychotherapeutic treatments. A search of studies published in English between 1991 and 2024 was conducted using PubMed. Eligible studies included those that assessed ODF before and after treatment using either the Defense Mechanism Rating Scale (DMRS) or the Defense Style Questionnaire (DSQ). Studies with very small or non-clinical samples were eliminated. The final synthesis included 14 effect sizes from 12 studies. A multilayered aggregated calculation was applied using R (version 4.4.3) with the readxl and metafor packages. ODF changes obtained d = 0.56, 95% CI [0.34, 0.78], z = 5.07, p < .001. Findings indicated a significant moderate effect in ODF changes during psychotherapies. Evidence is primarily limited by methodological heterogeneity and variation in assessment tools. Despite these limitations, the results support the effectiveness of psychotherapies in improving defense mechanisms, specifically when treatment duration is longer and through observer-rated interpretation. These conclusions highlight the clinical implications of defense restructuring across various psychotherapies.Show less

meta-analysis(

) defense mechanisms(

) psychotherapy(

) defensive functioning

Author

Argeșeanu, Gabriela

Faculty

Faculty of Social & Behavioural Sciences

Specialisation

Clinical psychology

Supervisors

Babl, A.M.

ECTS Credits

20

Language

en