Study on iTBS Regulating the Reward Circuit Function to Improve Anhedonia in Depression (iTMMDD)

Study on the Efficacy of iTBS Targeting NAc and sgACC in Regulating the Reward Circuit Function to Improve Anhedonia in Depression

The goal of this clinical trial is to learn if the proposed intermittent theta burst stimulation (iTBS) protocol can effectively improve anhedonia symptoms in depressed patients. The stimulation targets in our protocol include (1) dual-target stimulation at the left dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC). (2) single-target stimulation at the left DLPFC.

The main questions it aims to answer are:

• Whether iTBS of dual-target stimulation (left DLPFC and OFC) can improve the symptoms of anhedonia and better than single-target stimulation at the left DLPFC?
• Whether iTBS of the dual targets of left DLPFC and OFC can improve the symptoms of anhedonia by correcting the abnormal functional connectivity of DLPFC-NAc and OFC-sgACC, regulating the functional abnormalities of NAc and sgACC, and indirectly repairing the overall dysfunction of the reward circuit.
• Researchers will compare dual-target stimulation to single-target stimulation and sham dual-target stimulation (a dedicated sham coil is utilized which produces an identical audible click and physical sensation) to see if the proposed iTBS protocol works to treat anhedonia.

Participants will:

• Take 6 sessions of dual-target iTBS or single-target iTBS every day, for 5 consecutive days.
• Visit our hospital at 1 week, 4 weeks, and 8weeks after the iTBS treatment completion, for clinical evaluation and brain image examination.

Study Overview

• Status: Recruiting
• Conditions: Anhedonia; Major Depression; Melancholic Depression; Theta Burst Stimulation
• Intervention / Treatment: Device: Left DLPFC + OFC iTBS; Device: Left DLPFC iTBS

Detailed Description

Anhedonia, defined as the diminished capacity to experience pleasure, is a core symptom of Major Depressive Disorder (MDD). Patients with anhedonia exhibit a pervasive loss of interest or pleasure in all or almost all previously enjoyable activities, which frequently leads to a profound reduction in the desire to engage in rewarding behaviors. Previous studies have reported that anhedonia occurs in 37% to 72% of depressed individuals. Patients with depression accompanied by anhedonia tend to respond poorly to medication and psychotherapy but show relatively better responses to conventional physical treatments such as electroconvulsive therapy (ECT). Research has shown that improving anhedonia significantly enhances social functioning in depressed patients. Therefore, more effective treatments targeting anhedonia are needed. Achieving breakthroughs in therapeutic approaches and understanding their underlying mechanisms will contribute substantially to progress in this field.

Theta-burst stimulation (TBS) utilizes a stimulation pattern that closely mimics the natural firing frequencies of cerebral neurons. Accumulating evidence has demonstrated the clinical efficacy of intermittent TBS (iTBS) in alleviating depressive symptoms. Thus, this study aims to investigate and evaluate whether the proposed iTBS protocol can effectively improve anhedonia symptoms in depressed patients by regulating functional abnormalities.

The stimulation targets in our protocol include (1) dual-target stimulation at the left dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC). (2) single-target stimulation at the left DLPFC.

The main questions it aims to answer are:

1. Whether iTBS of dual-target stimulation (left DLPFC and OFC) can improve the symptoms of anhedonia and better than single-target stimulation?
2. Whether iTBS of the dual targets of left DLPFC and OFC can improve the anhedonia symptom by correcting the abnormal functional connectivity of DLPFC-NAc and OFC-sgACC, regulating the functional abnormalities of NAc and sgACC, and indirectly repairing the overall dysfunction of the reward circuit?

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Wenbin Guo, PhD; Phone Number: +86 73185360921; Email: guowenbin76@csu.edu.cn

Study Locations

• China
  • Hunan
    • Changsha, Hunan, China, 410000
      • Recruiting
      • The Second Xiangya Hospital of Central South University
      • Contact: Meiqi Yan, Master; Phone Number: +86 18155517736; Email: meiqi7012@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Aged 18-45 years, and right-handed;
2. Diagnosed with major depressive disorder (MDD) by at least two qualified psychiatrists, according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), with a Montgomery-Åsberg Depression Rating Scale (MADRS) score ≥ 20 or a 17-item Hamilton Depression Rating Scale (HAMD-17) score ≥ 17;
3. Evaluated by a psychiatrist as having prominent anhedonia, and meeting the cutoff criteria on two self-report anhedonia scales, including a Snaith-Hamilton Pleasure Scale, Chinese version (SHAPS-C) score ≥ 20, or a Temporal Experience of Pleasure Scale, Chinese version (TEPS-C) score ≤ 76;
4. Medication type and dosage remained unchanged for at least 4 weeks prior to treatment initiation and throughout the study period;
5. MADRS item 10 score ≤ 4.

Exclusion Criteria:

1. A history of epilepsy, seizures, stroke, or other serious organic brain diseases;
2. Presence of severe infectious diseases, malignant tumors, or other major unstable medical conditions;
3. Intellectual disability or developmental delay, presence of psychotic symptoms, or meeting the diagnostic criteria for other psychiatric disorders;
4. A history of substance abuse or psychoactive substance use;
5. Presence of intracranial implants (e.g., aneurysm clips, shunts, stimulators, cochlear implants, or electrodes), or any other metallic objects in or near the head that cannot be safely removed (excluding dental fillings);
6. Contraindications to MRI or structural intracranial abnormalities detected on MRI;
7. Pregnant or breastfeeding women;
8. Receipt of electroconvulsive therapy (ECT) within the past 6 months, or transcranial magnetic stimulation (TMS) within the past 3 months;
9. Current daily use of lorazepam > 2 mg (or an equivalent dose), or use of antiepileptic drugs at any dose;
10. Presence of strong suicidal ideation, or a MADRS item 10 score > 4.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Left DLPFC + OFC iTBS Group; iTBS Parameter Specifications: 60 cycles of 10 bursts of three pulses at 50 Hz were delivered in 2-second trains (5 Hz) with an 8-second intertrain interval. The total duration of a single session is 10 minutes, comprising 60 trains and yielding a total of 1,800 pulses per session. Treatment Protocol for Left DLPFC+OFC iTBS Group: Stimulations are first delivered to the left DLPFC-NAc functional region using the specified iTBS parameters (1,800 pulses per session), performed 3 sessions daily with a 50-minute interval between sessions. Subsequently, stimulation was applied to the left OFC-sgACC functional region with the identical parameters (1,800 pulses per session), also performed 3 sessions daily with a 50-minute interval. This yields a cumulative total of 10,800 pulses over 5 consecutive days, for a total of 54,000 pulses.	Device: Left DLPFC + OFC iTBS; iTBS Parameter Specifications: 60 cycles of 10 bursts of three pulses at 50 Hz were delivered in 2-second trains (5 Hz) with an 8-second intertrain interval. The total duration of a single session is 10 minutes, comprising 60 trains and yielding a total of 1,800 pulses per session. For the Left DLPFC + OFC iTBS Group, stimulation is first delivered to the left DLPFC-NAc functional region using the specified iTBS parameters (1,800 pulses per session), performed 3 sessions daily with a 50-minute interval between sessions. Subsequently, stimulation is applied to the left OFC-sgACC functional region with the identical parameters (1,800 pulses per session), also performed 3 sessions daily with a 50-minute interval. This yields a cumulative total of 10,800 pulses over 5 consecutive days, for a total of 54,000 pulses.; Other Names: intermittent theta-burst stimulation (iTBS)
Experimental: Left DLPFC iTBS Group; iTBS Parameter Specifications: 60 cycles of 10 bursts of three pulses at 50 Hz were delivered in 2-second trains (5 Hz) with an 8-second intertrain interval. The total duration of a single session is 10 minutes, comprising 60 trains and yielding a total of 1,800 pulses per session. Treatment Protocol for Left DLPFC iTBS Group: For Group B, stimulations are delivered solely to the left DLPFC-NAc functional region using the specified iTBS parameters, performed 6 sessions daily with a 50-minute interval between sessions. This yields a cumulative total of 10,800 pulses over 5 consecutive days, for a total of 54,000 pulses.	Device: Left DLPFC iTBS; iTBS Parameter Specifications: 60 cycles of 10 bursts of three pulses at 50 Hz were delivered in 2-second trains (5 Hz) with an 8-second intertrain interval. The total duration of a single session is 10 minutes, comprising 60 trains and yielding a total of 1,800 pulses per session. For the left DLPFC iTBS Group, stimulation is delivered solely to the left DLPFC-NAc functional region using the specified iTBS parameters, with 6 sessions performed daily, each with a 50-minute interval between sessions. This yields a cumulative total of 10,800 pulses over 5 consecutive days, for a total of 54,000 pulses.; Other Names: intermittent theta burst stimulation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total score of Montgomery-Åsberg Depression Rating Scale (MADRS)	The Montgomery-Åsberg Depression Rating Scale (MADRS) scores will be evaluated before and after treatment. Total score: 0-60. A higher score means worse depressive symptoms.	*Baseline; * Day 2- Day 6 (every treatment day); *1 week post-treatment; *4 weeks post-treatment; *8 weeks post-treatment.
Remission Rate of Montgomery-Åsberg Depression Rating Scale (MADRS) scores	The proportion of patients in each group achieving remission. Remission is defined as a MADRS score < 11 points.	* Day 2- Day 6 (every treatment day); *1 week post-treatment; *4 weeks post-treatment; *8 weeks post-treatment.
Response Rate of Montgomery-Åsberg Depression Rating Scale (MADRS) scores	The percentage change in MADRS scores from baseline, calculated as [(MADRSpre - MADRSpost) / MADRSpre] * 100%.	* Day 2- Day 6 (every treatment day); *1 week post-treatment; *4 weeks post-treatment; *8 weeks post-treatment.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total score of the Temporal Experience of Pleasure Scale - Chinese Version (TEPS-C)	Total score: 20-120. The lower score means worse anhedonia.	*Baseline; *Day 6; *1 week post-treatment; *4 weeks post-treatment; *8 weeks post-treatment.
Remission rate of Temporal Experience of Pleasure Scale - Chinese Version (TEPS-C) score	Remission means the TEPS-C score > 76. The TEPS-C remission rate is the proportion of patients in each group whose TEPS-C scores increased to >76 after treatment.	*Day 6; *1 week post-treatment; *4 weeks post-treatment; *8 weeks post-treatment.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total score of the 17-item Hamilton Depression Rating Scale (HAMD-17)	Total score: 0-52. A higher score means worse depressive symptoms.	*Baseline; *Day 6; *1 week post-treatment; *4 weeks post-treatment; *8 weeks post-treatment.
Total scores of the Chinese version of the Snaith-Hamilton Pleasure Scale (SHAPS-C) score	Total score: 14-56. A higher score means worse anhedonia.	*Baseline; *Day 6; *1 week post-treatment; *4 weeks post-treatment; *8 weeks post-treatment.
Brain MRI	Resting-state magnetic resonance imaging scans will be conducted. Resting-state functional connectivity (rs-FC) changes before and after treatment will be assessed by fMRI. And its potential correlation with clinical symptom changes will be further explored.	*Baseline; *Day 6, up to 1day delay; *8 weeks post-treatment.
Questionnaire: The Beck Scale for Suicide Ideation (BSI) scores	The Beck Scale for Suicide Ideation (BSI) scores will be evaluated before and after treatment. Total score: 0-38. Higher scores indicate greater severity of suicidal ideation.	*Baseline; *Day 6; * 1 week post-treatment; * 4 weeks post-treatment; * 8 weeks post-treatment.
Total Score of the Repeatable Battery for the Assessment of Neuropsychological Status Update (RBANS)	The RBANS is an instrument used to assess cognitive functioning. The Total Scale Score will be evaluated. The standard score range is typically 40 to 160 (index score based). A higher score indicates better cognitive performance.	*Baseline; *Day 6; * 8 weeks post-treatment.
Wisconsin Card Sorting Test (WCST) Perseverative Errors scores	The WCST is an assessment of executive function and cognitive flexibility. This measure evaluates the number of perseverative errors, which occur when a participant continues to apply a previous sorting rule after the rule has changed. For this 48-card version, the theoretical score ranges from 0 to 48. A higher score indicates worse cognitive flexibility and greater executive dysfunction.	*Baseline; *Day 6; *8 weeks post-treatment.

Collaborators and Investigators

• Sponsor: Guo Wenbin
• Investigators: Principal Investigator: Wenbin Guo, PhD, Second Xiangya Hospital of Central South University

Study record dates

Study Major Dates

• Study Start (Actual): May 19, 2026
• Primary Completion (Estimated): July 3, 2027
• Study Completion (Estimated): July 3, 2027

Study Registration Dates

• First Submitted: May 24, 2026
• First Submitted That Met QC Criteria: September 8, 2026
• First Posted (Actual): September 10, 2026

Study Record Updates

• Last Update Posted (Actual): September 10, 2026
• Last Update Submitted That Met QC Criteria: September 8, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Neurobehavioral Manifestations; Mood Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Depressive Disorder; Depressive Disorder, Major; Anhedonia
• Other Study ID Numbers: LYG20260013; ChiCTR2600125718 (Registry Identifier: Chinese Clinical Trial Registry)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared to ensure strict confidentiality and protect participant privacy.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No