Dose-response effects of cognitive control training on depression

Vander Zwalmen, Y., Demeester, D., Hoorelbeke, K., Verhaeghe, N., Baeken, C., & Koster, E. H. W. (2025). The more, the merrier? Establishing a dose–response relationship for the effects of cognitive control training on depressive symptomatology. Journal of Consulting and Clinical Psychology, 93(3), 161–175. https://doi.org/10.1037/ccp0000945

Rationale

Depression is prevalent globally, with high recurrence rates (Bockting et al., 2015).

Cognitive impairments often persist after depressive episodes and increase recurrence risk (Buckman et al., 2018; Semkovska et al., 2019).

Cognitive control, important for regulating emotions (Joormann & Vanderlind, 2014), is targeted by computerized cognitive control training (CCT), which has shown effectiveness in reducing depressive symptoms (Siegle et al., 2007; Hoorelbeke & Koster, 2017).

Previous research using adaptive PASAT (aPASAT) indicated positive effects, but optimal training dosage remained unclear (Vander Zwalmen, Liebaert et al., 2024).

This study addresses the gap by experimentally examining dose-response relationships using randomized controlled methods to clarify optimal CCT dosage for sustained symptom improvement and inform clinical practice.

Method

The study used a randomized controlled trial design.

Participants were randomly assigned to one of six groups, each receiving a different amount of cognitive control training (CCT) sessions over 4 weeks.

Depressive symptoms and other cognitive and emotional transfer effects were examined shortly after training, as well as at 3- and 6-month follow-ups.  

Procedure:

The study procedure consisted of:

• Telephone screening and lab baseline measures.
• Random assignment to 0, 1, 5, 10, 15, or 20 training sessions (15 minutes each).
• Training completed at home.
• Post-training lab measures.
• Follow-up assessments at 3 and 6 months.

Sample:

• The study included 216 participants.  
• Participants were individuals with remitted depression.  
• The study did not report the racial or ethnic background of participants.
• The age range of participants was 18-71 years old. The average age of participants across the six groups was between 35.9 and 40.1 years old.  
• Breakdown of gender for each group is as follows:
  • Control Group: 7 males, 30 females
  • 1-Session Group: 13 males, 25 females
  • 5-Session Group: 11 males, 25 females, 1 other
  • 10-Session Group: 14 males, 22 females
  • 15-Session Group: 14 males, 18 females
  • 20-Session Group: 14 males, 18 females, 4 other  

Measures:

The study used self-report questionnaires and cognitive tasks to measure outcomes.  

• Task-specific transfer: Assessed with a standardized version of the Paced Auditory Serial Addition Task (PASAT).  
• Near transfer: Measured with a dual n-back task.  
• Subjective cognitive functioning: Measured with the effortful control (EC) subscale of the Adult Temperament Questionnaire (ATQ-EC).  
• Depressive symptomatology: Assessed with the Beck Depression Inventory-II (BDI-II).  
• Residual depressive complaints: Remission from Depression Questionnaire (RDQ)

Results

Hypothesis 1:

The study hypothesized a dose-response relationship between cognitive control training (CCT) and depressive symptoms in individuals with remitted depression.

Result:

The study found that a minimum of 10 CCT sessions was required for a significant decrease in depressive symptoms shortly after training.

This effect was observed for groups that completed 10 and 20 CCT sessions.  

Hypothesis 2:

The study also explored the effects of CCT on other cognitive and emotional transfer effects.

Result:

Reductions in perseverative thinking were observed in groups that received 10 or more CCT sessions, and these reductions remained present until the 6-month follow-up.  

Insight

This study is informative because it systematically examined the dose-response relationship of CCT in individuals with remitted depression.

The finding that at least 10 CCT sessions are needed to produce short-term improvements in depressive symptoms and long-term reductions in perseverative thinking extends previous research by providing specific dosage recommendations.

Previous research had shown that CCT has positive effects, but it was unclear how many sessions are needed for these benefits.

The study’s results suggest that a minimum “dose” of CCT is necessary to achieve clinical benefits.

Future research could investigate the mechanisms underlying these dose-dependent effects and explore the optimal spacing of CCT sessions.

Additionally, research is needed to determine if continued training or booster sessions can maintain the improvement in depressive symptoms over the long term.  

Implications

The findings from this study may inform clinical practice by providing evidence-based recommendations for the dosage of CCT in individuals with remitted depression.

Practitioners can use this information to determine the appropriate number of CCT sessions to include in treatment plans.

Specifically, a minimum of 10 CCT sessions is recommended to achieve benefits in depressive symptoms and perseverative thinking. I

mplementing CCT with an adequate number of sessions may improve treatment outcomes and reduce the risk of depression recurrence.

However, challenges in implementing CCT may include ensuring patient adherence to the training protocol and providing sufficient resources for CCT delivery.  

Strengths

• Employed a randomized controlled trial design.  
• Included a dose-response manipulation with multiple training session groups.  
• Assessed outcomes at multiple time points, including long-term follow-ups.  
• Used a computerized and gamified version of the aPASAT to optimize user engagement.  
• Had a large sample size.  

Limitations

• The study did not include an active control group.
• Exclusive reliance on self-report measures.
• The generalizability of the findings may be limited by the specific characteristics of the sample (e.g., individuals with remitted depression).  

References

Vander Zwalmen, Y., Demeester, D., Hoorelbeke, K., Verhaeghe, N., Baeken, C., & Koster, E. H. W. (2025). The more, the merrier? Establishing a dose–response relationship for the effects of cognitive control training on depressive symptomatology. Journal of Consulting and Clinical Psychology, 93(3), 161–175. https://doi.org/10.1037/ccp0000945

• Bockting, C. L., Hollon, S. D., Jarrett, R. B., Kuyken, W., & Dobson, K. (2015). A lifetime approach to major depressive disorder: The contributions of psychological interventions in preventing relapse and recurrence. Clinical Psychology Review, 41, 16–26. https://doi.org/10.1016/j.cpr.2015.02.003
• Buckman, J. E. J., Underwood, A., Clarke, K., Saunders, R., Hollon, S. D., Fearon, P., & Pilling, S. (2018). Risk factors for relapse and recurrence of depression in adults and how they operate: A four-phase systematic review and meta-synthesis. Clinical Psychology Review, 64, 13–38. https://doi.org/10.1016/j.cpr.2018.07.005
• Hoorelbeke, K., & Koster, E. H. W. (2017). Internet-delivered cognitive control training as a preventive intervention for remitted depressed patients: Evidence from a double-blind randomized controlled trial study. Journal of Consulting and Clinical Psychology, 85(2), 135–146. https://doi.org/10.1037/ccp0000128
• Joormann, J., & Vanderlind, W. M. (2014). Emotion regulation in depression. Clinical Psychological Science, 2(4), 402–421. https://doi.org/10.1177/2167702614536163
• Semkovska, M., Quinlivan, L., O’Grady, T., Johnson, R., Collins, A., O’Connor, J., Knittle, H., Ahern, E., & Gload, T. (2019). Cognitive function following a major depressive episode: A systematic review and meta-analysis. The Lancet Psychiatry, 6(10), 851–861. https://doi.org/10.1016/S2215-0366(19)30291-3
• Siegle, G. J., Ghinassi, F., & Thase, M. E. (2007). Neurobehavioral therapies in the 21st century: Summary of an emerging field and an extended example of cognitive control training for depression. Cognitive Therapy and Research, 31(2), 235–262. https://doi.org/10.1007/s10608-006-9118-6
• Vander Zwalmen, Y., Liebaert, E., Hoorelbeke, K., Nunez Castellar, E. P., Baeken, C., & Koster, E. H. W. (2024). Cognitive remediation for depression vulnerability: Current challenges and new directions. Frontiers in Psychology, 13, Article 903446. https://doi.org/10.3389/fpsyg.2022.903446

Socratic Questions

How could future research address the limitations of this study to further our understanding of the dose-response relationship of CCT?

How might the absence of an active control group limit the conclusions that can be drawn from this study?

In what ways could the reliance on self-report measures introduce potential biases into the study’s findings?

How might the findings of this study be applied to individuals with different types or severities of depression?

What are the potential challenges in implementing cognitive control training (CCT) in real-world clinical settings?