Theory and prior research suggests that patients’ attachment orientations may be an important moderator that impacts treatment efficacy (Levy et al., 2018). Attachment theory provides a framework for understanding individual differences in interpersonal characteristics and patterns of emotional regulation (Mikulincer & Shaver, 2007). Patients with anxious attachment tend to desperately seek closeness, while avoidant patients suppress attachment needs.
Zilcha-Mano, S., Goldstein, P., Dolev-Amit, T., Ben David-Sela, T., & Barber, J. P. (2021). A randomized controlled trial for identifying the most suitable treatment for depression based on patients’ attachment orientation. Journal of Consulting and Clinical Psychology, 89(12), 985–994. https://doi.org/10.1037/ccp0000696
Key Points
- This randomized controlled trial (RCT) is the first designed a priori to test whether patients’ attachment orientations moderate the efficacy of two psychotherapies for depression.
- Patients were randomly assigned to 16 weeks of supportive therapy (ST) focused on providing emotional support, or supportive-expressive therapy (SET), combining emotional support with expressive techniques to explore conflicts.
- As hypothesized, attachment anxiety moderated outcomes – anxious patients benefited more from SET than ST. However, attachment avoidance did not moderate outcomes.
- In exploratory analyses, patients high in both attachment anxiety and avoidance (disorganized attachment) also benefited more from SET than ST.
- The findings demonstrate the clinical utility of using attachment orientation to match patients to optimal therapy. More RCTs designed a priori to test such precision medicine approaches are needed.
Rationale
Depression is highly prevalent globally, but many available psychosocial treatments have similar modest response rates of around 50% (Cuijpers, 2017). This highlights the need to identify which treatments work best for which patients.
Theory and research suggest patients’ attachment orientations may moderate treatment efficacy, but most studies are correlational or post hoc analyses.
Most studies examining attachment as a moderator of depression treatment outcomes are correlational or post hoc analyses, yielding mixed findings.
This RCT was the first prospectively designed to test whether patients with contrasting attachment anxiety would respond differently to therapies theorized to operate via distinct mechanisms.
Specifically, anxious patients were expected to benefit more from exploratory supportive-expressive therapy (SET) challenging their attachment patterns, while avoidant patients would fare better with emotionally supportive supportive therapy (ST) (Daly & Mallinckrodt, 2009).
Method
Patients were randomly allocated to 16 weekly sessions of supportive therapy (ST) or supportive-expressive therapy (SET) using a validated balancing procedure to optimize baseline equivalence across conditions.
Therapists with over 5 years of clinical experience delivered both interventions following specialized training and certification. Adherence was confirmed through coded video review.
Assessments were conducted at baseline and weekly for depression severity (HAM-D). The 36-item Experiences in Close Relationships scale (ECR) measured attachment anxiety and avoidance dimensions pre-treatment.
Sample
100 clinically depressed Israeli outpatients aged 18-60 years (mean 31 years), 57% female. Exclusions included bipolar disorder, psychosis, and eating disorders.
Statistical Analysis
Moderation was tested using multilevel models with pre-registered hypotheses.
Multilevel models tested treatment condition by attachment orientation interactions on depression trajectory, controlling for nesting within therapists. Logistic regressions tested moderating effects on categorical outcomes.
Categorical outcomes like response rates (50% improvement) were compared via logistic regression.
The trial design, hypotheses and analysis plan were pre-registered to uniquely evaluate attachment orientation as the first prospectively examined moderator of differential psychotherapy efficacy (see Zilcha-Mano et al., 2018).
Results
This rigorous randomized trial found no overall differences in improvement between supportive therapy (ST) and supportive-expressive therapy (SET) for depression. Both treatments had response rates of around 70%.
However, there were significant differences in outcomes when considering patients’ attachment styles measured at baseline:
- Anxiously attached patients, who desperately seek closeness and struggle with regulating emotions, had better depression improvement in SET than ST. The difference was clinically meaningful.
- Avoidantly attached patients, who suppress emotional needs and distance from others, did not have significantly different outcomes between therapies. Avoidance did not predict optimal treatment response.
- In exploratory analyses, patients showing a disorganized attachment style high in both attachment anxiety and avoidance benefited the most from SET, which integrates supportive and expressive elements.
Insight
This pioneering RCT provides proof-of-concept for the clinical utility of matching patients with contrasting attachment styles to therapies targeting distinct mechanisms of change.
Patients prone to clinging in relationships responded better to therapy addressing those relationship patterns, compared to supportive talk therapy alone. However, patients who dismiss intimacy showed similar improvements across approaches.
Larger prospective moderator trials and research explicating attachment changes in therapy can further advance personalized mental healthcare.
The findings also reveal limitations around using avoidance alone to personalize treatment, given attachment styles may shift over therapy.
Strengths
- RCT prospectively designed to test moderator hypotheses
- Use of validated attachment measure
- Robust analytic approach controlling for nesting within therapists
- High retention and data completeness
Limitations
- Small sample, with limited power to detect smaller effects
- Used self-report attachment measure
- Israeli outpatients may differ from other populations
- Did not study patient-therapist attachment match
Implications
The clinically significant moderating effects for attachment anxiety and disorganized attachment suggest assessing patient attachment could improve outcomes by guiding personalized therapy selection.
The lack of avoidance effects indicates a more nuanced approach is needed for guiding precision mental health.
Keep Learning
- Why might assessing patient characteristics like attachment styles be important for selecting optimal therapies? What other characteristics might be relevant treatment moderators?
- This study found attachment anxiety but not avoidance moderated outcomes. Why might that be? How might attachment styles change over the course of therapy?
- What additional research is needed to translate these findings into more precision mental healthcare? What barriers stand in the way?
- How could the theoretical basis, scientific rigor, and real-world applicability of research on personalized therapy be improved? Which stakeholders need to be involved?
References
Primary reference
Zilcha-Mano, S., Goldstein, P., Dolev-Amit, T., Ben David-Sela, T., & Barber, J. P. (2021). A randomized controlled trial for identifying the most suitable treatment for depression based on patients’ attachment orientation. Journal of Consulting and Clinical Psychology, 89(12), 985–994. https://doi.org/10.1037/ccp0000696
Other references
Cuijpers, P. (2017). Four decades of outcome research on psychotherapies for adult depression: An overview of a series of meta-analyses. Canadian Psychology/Psychologie canadienne, 58(1), 7–19. https://doi.org/10.1037/cap0000096
Daly, K. D., & Mallinckrodt, B. (2009). Experienced therapists’ approach to psychotherapy for adults with attachment avoidance or attachment anxiety. Journal of Counseling Psychology, 56(4), 549–563. https://doi.org/10.1037/a0016695
Friedrich, M. J. (2017). Depression is the leading cause of disability around the world. JAMA, 317(15), 1517. https://doi.org/10.1001/jama.2017.3826
Levy, K. N., Kivity, Y., Johnson, B. N., & Gooch, C. V. (2018). Adult attachment as a predictor and moderator of psychotherapy outcome: A meta-analysis. Journal of Clinical Psychology, 74(11), 1996–2013. https://doi.org/10.1002/jclp.22685
Mikulincer, M., & Shaver, P. R. (2007). Attachment in adulthood: Structure, dynamics, and change. Guilford Press.
Zilcha-Mano, S., Dolev, T., Leibovich, L., & Barber, J. P. (2018). Identifying the most suitable treatment for depression based on patients’ attachment: Study protocol for a randomized controlled trial of supportive-expressive vs. supportive treatments. BMC psychiatry, 18(1), 1-8.
