Shared and Unique Changes in Brain Connectivity among Depressed Patients Remitting with Pharmacotherapy vs. Psychotherapy

Author Information

• Boadie W. Dunlop, MD
  Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA

• Jungho Cha, PhD
  Department of Neurology and Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA

• Ki Sueng Choi, PhD
  Department of Neurology and Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA

• Justin K. Rajendra, BA
  Scientific and Statistical Computational Core, National Institute of Mental Health, Bethesda, MD, USA

• Charles B. Nemeroff, MD, PhD
  Department of Psychiatry and Behavioral Sciences, Institute for Early Life Adversity Research, University of Texas at Austin Dell Medical School, Austin, TX, USA

• W. Edward Craighead, PhD
  Department of Psychology, Emory University, Atlanta, GA, USA

• Helen S. Mayberg, MD
  Department of Neurology and Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA

Abstract

Objective

• To determine the shared and unique changes in brain resting state functional connectivity (RSFC) between patients with major depressive disorder (MDD) achieving remission through cognitive behavior therapy (CBT) vs. antidepressant medication (ADM).

Methods

• PReDICT Trial Design:

  • Randomized adults with treatment-naïve MDD to treatment over 12 weeks.

  • Treatments: 16 individual sessions of CBT or ADM (duloxetine 30–60 mg/day and escitalopram 10–20 mg/day).

  • RSFC Measurement: Resting state functional magnetic resonance imaging (fMRI) scans performed at baseline and week 12.

• Outcome:

  • Change in whole brain RSFC of four seeded brain networks among participants achieving remission.

Results

• Participants: 131 completers (74 female, mean age 39.8 years).

  • Remission achieved by 19 of 40 CBT-treated participants and 45 of 91 medication-treated participants.

• Connectivity Changes Observed:

  1. Shared reduction in RSFC between the subcallosal cingulate cortex and motor cortex for both treatment types.

  2. Reciprocal RSFC changes across multiple networks: primarily increases in CBT remitters, decreases in medication remitters.

  3. In CBT remitters, increased RSFC within the executive control network and its relation to parietal attention regions.

Conclusions

• Remission from MDD relates to unique RSFC changes specific to treatment modality, supporting the clinical practice of treatment switching or combining methods.

• Medication linked to generally inhibitory effects, while CBT enhances RSFC in cognitive control and attention networks.

• Both treatments share a reduction in affective network connectivity with motor systems critical for remission.

Introduction

• Major Depressive Disorder (MDD): Common, debilitating disorder treated primarily through ADM or psychotherapy like CBT.

• Research Goals:

  • Investigate effects of treatment on brain networks via rs-fMRI.

  • Understand shared vs. unique effects of treatments on RSFC that influence outcomes for patients.

  • Address previous limited empirical data on contrasting brain changes post-treatment.

Key Brain Networks in MDD

1. Default Mode Network (DMN)

   • Composed of medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), precuneus, inferior parietal lobes.

   • Dominates during internally focused tasks.

2. Executive Control Network (ECN)

   • Involves the dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), posterior parietal cortex.

   • Important for external task engagement and emotional regulation.

3. Salience Network (SN)

   • Contains ACC, anterior insula, and various subcortical structures (e.g., amygdala).

   • Responsible for detecting and responding to relevant stimuli.

4. Affective Network (AN)

   • Includes key regions for processing affective states, such as SCC.

Study Design and Participants

• Randomized Controlled Trial (PReDICT):

  • Conducted at Emory University and Grady Hospital (2007-2013); approved by relevant IRBs.

  • Included treatment-naïve adults 18-65 years with moderate to severe MDD (HAMD scores).

  • Randomization was 1:1:1 across three treatment groups: duloxetine, escitalopram, or CBT.

Primary Outcomes

1. Remission: Achieve HAMD score ≤ 7 at weeks 10 and 12.

2. Response without remission: ≥50% reduction in HAMD, but >7 at endpoint.

3. Non-response: <50% reduction in HAMD.

Functional MRI Acquisition and Analysis

• fMRI scans were done before randomization and prior to week 12.

• Seed Locations for RSFC Analyses: Involved four major brain networks (DMN, ECN, SN, AN) using 5mm radius spheres.

• Statistical Analysis: Linear mixed effects (LME) models to evaluate RSFC patterns across time and treatment type; permutation analyses employed for robustness.

Results

Demographics and Remission Rates

• Study sample: 131 patients (mean age 39.8; 56.5% female).

• Remission rates: 49.5% for ADM and 47.5% for CBT group.

Shared and Unique Connectivity Changes

1. Shared Changes:

   • Statistically significant reduction in RSFC between SCC and left medial motor cortex for both treatment groups.

   • Reductions specific to remitters, not seen in non-remitting patients.

2. Unique Changes per Treatment:

   • CBT Remitters: Significant increased connectivity within the ECN, particularly with parietal attention regions.

   • ADM Remitters: Showed more inhibitory connectivity changes (i.e., decreased RSFC).

   • Comparisons to healthy controls were made for clarity of recovery in connectivity patterns.

Discussion

• Key Findings:

  • Significance of reduced SCC-mM1 RSFC suggests potential importance of disinhibiting motor activation for improving depressive symptoms.

  • The ECN's role in CBT aligns with theories of cognitive control needed to manage depressive symptoms.

  • Observations of increased RSFC between attention networks and primary cognitive functions in CBT remitters exemplify effective treatment mechanisms.

• Implications for Treatment:

  • Understanding RSFC shifts can lead to improved personalized therapy options and indicate when to switch or combine treatments effectively (CBT and ADM).

Conclusion

• The study highlights the distinct and shared neurobiological mechanisms by which CBT and ADM lead to recovery in MDD, calling for further inquiries into personalized treatments.

Acknowledgments

• Supported by multiple NIH grants and contributions from pharmaceutical companies for study medications.

References

• Comprehensive listing of studies detailing effects of treatments on brain connectivity, underpinning findings presented in the study.

Here's how you can leverage the provided research paper "Shared and Unique Changes in Brain Connectivity among Depressed Patients Remitting with Pharmacotherapy vs. Psychotherapy" for your essay, focusing on the psychology/behavioral science viewpoint.

Useful Information / Key Points from the Study

These points can be integrated into your "Literature Review" section under the behavioral science viewpoint, or within your "Worldview Issues" section when discussing how psychology understands what goes wrong in depression.

1. Objective of the Study: The research aimed "to determine the shared and unique changes in brain resting state functional connectivity (RSFC) between patients with major depressive disorder (MDD) achieving remission through cognitive behavior therapy (CBT) vs. antidepressant medication (ADM)."

2. Methodology - Focus on Brain Connectivity: The study used "Resting state functional magnetic resonance imaging (fMRI) scans performed at baseline and week 12" to measure RSFC across four seeded brain networks: Default Mode Network (DMN), Executive Control Network (ECN), Salience Network (SN), and Affective Network (AN). This highlights a neurobiological focus in understanding depression and its treatment.

3. Key Brain Networks in MDD: The paper identifies specific networks relevant to MDD and psychological functioning:

   • Default Mode Network (DMN): "Dominates during internally focused tasks" and involves regions like the medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC).

   • Executive Control Network (ECN): "Important for external task engagement and emotional regulation," involving the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC).

   • Salience Network (SN): "Responsible for detecting and responding to relevant stimuli," including the ACC and anterior insula.

   • Affective Network (AN): Includes regions like the subcallosal cingulate cortex (SCC), crucial for processing affective states.

4. Shared Mechanisms of Remission: A significant finding was a "Shared reduction in RSFC between the subcallosal cingulate cortex and motor cortex for both treatment types." This suggests a common neurobiological pathway, specifically "reduction in effective network connectivity with motor systems critical for remission," regardless of whether CBT or ADM was used. The discussion elaborates on this: "Significance of reduced SCC-mM1 RSFC suggests potential importance of disinhibiting motor activation for improving depressive symptoms."

5. Unique Mechanisms of Remission (Treatment-Specific):

   • CBT Remitters: Exhibited "increased RSFC within the executive control network and its relation to parietal attention regions." The discussion reinforces this: "The ECN's role in CBT aligns with theories of cognitive control needed to manage depressive symptoms." Also, "Observations of increased RSFC between attention networks and primary cognitive functions in CBT remitters exemplify effective treatment mechanisms."

   • ADM Remitters: Showed "more inhibitory connectivity changes (i.e., decreased RSFC)" or "generally inhibitory effects."

6. Implications for Treatment: The study concludes that "Remission from MDD relates to unique RSFC changes specific to treatment modality, supporting the clinical practice of treatment switching or combining methods." Understanding these "RSFC shifts can lead to improved personalized therapy options."

Integrating Information into Your Essay (Psychology Behavioral Science Viewpoint)

When writing your essay, especially the "Literature Review" and "Discussion" sections, consider the following for seamless integration of this psychological research:

1. Introduction to Psychological Perspective on Depression: Start by explaining how psychology, particularly cognitive neuroscience, views depression—as a disorder involving dysregulated brain networks and cognitive processes. This study provides empirical evidence for these network changes.

2. Epistemology (Naturalism vs. Supernaturalism):

   • Emphasize a Strictly Psychological (Naturalistic) Epistemology: This study exemplifies a naturalistic approach. It focuses on observable, measurable biological (brain connectivity) and behavioral (response to therapy) phenomena. The causes and treatments are explored within the realm of physical and cognitive processes, without invoking supernatural explanations. You can state that "a strictly psychological epistemology, as demonstrated by studies like Dunlop et al. (2019), focuses on quantifiable changes in brain resting state functional connectivity (RSFC) as both indicators of depressive states and as targets for therapeutic intervention." The causes are seen as imbalances or dysregulations within these neural networks, and treatments aim to re-regulate them.

   • Causes: From this perspective, depression is caused by altered brain connectivity (e.g., within the DMN, ECN, AN, SN) and cognitive patterns (addressed by CBT). Mention specific changes identified: "reductions in RSFC between SCC and motor cortex," "inhibitory effects of medication," and "enhanced RSFC in cognitive control and attention networks with CBT."

   • Treatments: The study squarely places treatments within empirical psychological and pharmacological interventions. "Treatments are designed to normalize these brain functions, either through pharmacological agents that alter neurochemistry and subsequent connectivity, or through psychotherapeutic approaches like CBT that teach cognitive and behavioral strategies to rewire maladaptive thought patterns and, consequently, brain network interactions."

3. Human Nature and Functioning (Psychological Lens): From a psychological standpoint, healthy psychological functioning involves optimal regulation of these brain networks, enabling effective emotional regulation, cognitive control, and appropriate responses to stimuli. Depression is when these systems fail, leading to internal focus (DMN overactivity), impaired executive function (ECN dysregulation), and disturbed affective processing (AN issues).

4. Connecting to Your Personal Theory of Integration: In your "Discussion" section, after presenting the psychological findings, you can begin to reconcile this naturalistic understanding with your broader worldview (cosmology, anthropology, sin, atonement). For example:

   • How might psychological causes (brain dysregulation) relate to your understanding of 'sin' (e.g., 'social sin' contributing to stress, 'personal sin' leading to maladaptive thought patterns that manifest neurobiologically)?

   • Does a naturalistic treatment (like CBT or ADM) fall short of a holistic 'fix' if it doesn't address spiritual dimensions, or does it represent a valid remediation of the physical/cognitive aspects of human brokenness? The study's finding that both treatments lead to remission with distinct brain changes can support the idea that different pathways can lead to healing, potentially opening space for integrating spiritual interventions as complementary.

   • Consider how the "inhibitory effects" of medication versus the "enhancement of cognitive control" by CBT might align with different spiritual disciplines or understandings of human agency in healing.

By carefully selecting these points and explicitly discussing the underlying epistemology of the psychological research, you can effectively integrate this valuable scientific perspective into your critical assignment.