EEG Microstate Alterations in Anhedonia Subtypes of Major Depressive Disorder and Their Modulation by Intermittent Theta-Burst Stimulation.

EEG microstate patterns changed differently in lower- and higher-anhedonia groups during two weeks of iTBS. Without sham treatment, the study cannot show that stimulation caused the clinical or EEG changes.

Wu J, Deng Z, Cheng X, Li S, Qiu N, Hu L, Chen Z, Yao D, Pu L, Yan H.
Depression and anxiety · Publication date: 2026-09-21
Added to site: 2026-09-24
DOI: 10.1155/da/1982576

Electronic publication date verified in Europe PMC and the full-text article XML; first indexed 2026-09-23. This source date is separate from the site's addition date.

Modalities

iTBS, rTMS, EEG

Clinical focus

Major depressive disorder, Anhedonia, EEG microstates

Population

Right-handed adults aged 18 to 60 with major depressive disorder and clinically significant anhedonia; healthy controls were matched on age, sex and education

Sample

50 adults with major depressive disorder, 25 with high anhedonia and 25 with low anhedonia, plus 25 healthy controls

Intervention / method

Twice-daily weekday iTBS over the left dorsolateral prefrontal cortex for two weeks, with resting EEG before and after treatment

Comparator

High- versus low-anhedonia patient subgroups and healthy controls; no sham stimulation

Clinician summary

After iTBS, most low-anhedonia microstate measures no longer differed from controls, while several abnormalities persisted in the high-anhedonia group. Within the high-anhedonia group, symptom improvement correlated with changes in microstate A and B duration.

How to interpret the findings

No sham arm, 25 patients per subgroup, two-week intervention, no long-term follow-up, medication heterogeneity and subtype classification based on a single questionnaire. Microstate-to-network interpretations are group-level candidates, not validated individual treatment selectors.

Equipment and disclosures

Wuhan Yiruide TMS system with an iron-core figure-8 coil; 64-channel BrainAmp MR32 EEG amplifier

Supported by China's Brain Science and Brain-like Intelligence Technology major project, the National Natural Science Foundation of China, the S&T Special Program of Huzhou and the Chengdu Municipal Health Commission. The authors declared no conflicts of interest.

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