Molecular Signatures of TMS Response in Treatment-Resistant Depression

Official title

The Relationship Between Plasma Metabolomics and Proteomics Profiling and Response to Transcranial Magnetic Stimulation Therapy in Treatment-Resistant Depression

Overview

Transcranial Magnetic Stimulation (TMS) therapy is an approved and effective treatment option for treatment-resistant depression (TRD). This study aims to identify biomarkers that predict TMS treatment response in TRD, provide insights into the neurobiological mechanisms underlying TMS efficacy, and contribute to personalized treatment strategies. By establishing proteomic and metabolomic signatures, this research seeks to enhance clinical decision-making, reduce healthcare costs, and improve patient outcomes in TRD. The findings will align with the precision medicine movement in psychiatry, advancing biomarker-driven therapeutic approaches for treatment-resistant depression.

Detailed description

This prospective cohort study aims to investigate the relationship between plasma proteomic and metabolomic profiles and the treatment response to transcranial magnetic stimulation (TMS) in patients with treatment-resistant depression (TRD). TRD is defined as a subtype of major depressive disorder (MDD), characterized by an inadequate response to at least two adequate trials of antidepressant therapy. Despite the clinical efficacy of TMS as a non-invasive neuromodulation treatment, the biological underpinnings that determine patient responsiveness remain unclear. This study addresses that gap by evaluating blood-based molecular biomarkers that may predict or reflect TMS treatment outcomes.

A total of 55 TRD patients, diagnosed according to DSM-5-TR criteria and confirmed through the SCID-5 structured clinical interview, will be enrolled. An additional 55 healthy individuals matched for age and sex will serve as a control group for baseline plasma comparisons. Patients will undergo a standardized TMS protocol using the MagVenture™ X100™ device. The protocol includes 20 treatment sessions over four weeks, with each session delivering 1,800 pulses of intermittent theta burst stimulation (iTBS) targeting the left dorsolateral prefrontal cortex (DLPFC). Motor threshold will be assessed weekly to calibrate treatment intensity to 90% of the resting motor threshold.

Blood samples will be collected from TRD patients prior to the first TMS session and after the 20th session, while healthy controls will provide samples at a single time point. Proteomic analysis will be conducted using LC-MS/MS following protein extraction, digestion, and purification. Metabolomic profiling will be carried out using LC-MS coupled with ion mobility spectrometry, enabling the identification of a wide range of plasma metabolites.

Psychiatric assessments, including the Hamilton Depression Rating Scale (HAM-D), Patient Health Questionnaire-9 (PHQ-9), Pittsburgh Sleep Quality Index (PSQI), and the Clinical Global Impression (CGI) scale, will be administered at baseline and post-treatment to monitor clinical outcomes. Data integration and bioinformatics analyses will be performed using MaxQuant, Perseus, and MetaboAnalyst 6.0, enabling the identification of differentially expressed proteins and metabolites associated with treatment response.

The primary objective of the study is to determine whether plasma proteomic and metabolomic profiles differ significantly between TMS responders and non-responders. Secondary objectives include identifying predictive biomarkers for TMS efficacy and assessing biological changes correlated with clinical improvement.

Primary outcomes will focus on identifying molecular signatures that correlate with treatment responsiveness. Secondary outcomes will include changes in depression severity scores, documentation of any adverse effects related to TMS, and examination of correlations between biomarker expression and pharmacological history.

This study is crucial for advancing personalized treatment approaches in psychiatry. By identifying objective, blood-based biomarkers of TMS response, it may become possible to tailor treatment strategies, reduce unnecessary interventions, and improve therapeutic outcomes for individuals suffering from TRD.

Interventions

• Device TMS
  Transcranial Magnetic Stimulation (TMS) is a non-invasive brain stimulation technique approved for the treatment of major depressive disorder (MDD), particularly in individuals with treatment-resistant depression (TRD). TMS targets the left dorsolateral prefrontal cortex (DLPFC), a brain region often underactive in depression, and modulates neural activity through magnetic pulses. This study aims to evaluate the effects of TMS on plasma proteomic and metabolomic profiles in patients with TRD. P

Primary outcome measures

• Plasma Proteomic Profile Changes After TMS in Patients with Treatment-Resistant Depression [Time frame: From enrollment to end of treatment at 4 weeks]
• Plasma Metabolomic Profile Changes After TMS in Patients with Treatment-Resistant Depression [Time frame: From enrollment to end of treatment at 4 weeks]
• Fold Change in Baseline Proteomic Markers Between Treatment Responders and Non-Responders [Time frame: From enrollment to end of the treatment at 4 weeks]
• Variable Importance in Projection Scores of Predictive Proteins [Time frame: Baseline and End of 4-week treatment]
• Area Under the ROC Curve for Predictive Proteomic Markers Between Treatment Responders and Non-Responders [Time frame: Baseline and End of 4-week treatment]
• Fold Change in Baseline Plasma Metabolomic Markers Between TMS Responders and Non-Responders [Time frame: Baseline]
• Variable Importance in Projection Scores of Baseline Plasma Metabolomic Markers Between TMS Responders and Non-Responders [Time frame: Baseline and End of 4-week treatment]
• Area Under the ROC Curve of Baseline Plasma Metabolomic Markers Between TMS Responders and Non-Responders [Time frame: Baseline and End of 4-week treatment]

Secondary outcome measures (6)

• Change in Depression Severity Based on Hamilton Depression Rating Scale (HAM-D, 17-item) [Time frame: From enrollment to the end of the treatment at 4 weeks]
• Change in Depression Severity Based on Patient Health Questionnaire-9 (PHQ-9) [Time frame: From enrollment to the end of the treatment at 4 weeks]
• Change in Subjective Sleep Quality Measured by Pittsburgh Sleep Quality Index [Sleep Quality] [Time frame: From enrollment to end of the treatment 4 weeks]
• Correlation Between Antidepressant Medication Use and Clinical Response to TMS Measured by Hamilton Depression Rating Scale-17 [Time frame: From enrollment to end of the treatment at 4 weeks]
• Change in Headache and Scalp Pain Severity Measured by Visual Analog Scale (VAS) [Tolerability] [Time frame: Baseline and End of 4-week treatment]
• Incidence of Seizure Events [Time frame: From enrollment to end of the 4 weeks]

Eligibility criteria

Inclusion criteria

• Diagnosis of Major Depressive Disorder (MDD) according to DSM-5-TR criteria.
• Inadequate clinical response to at least two different antidepressants and/or anti-obsessive agents administered at therapeutic doses and durations.
• Clinical symptoms not better explained by metabolic or organic medical conditions.
• No epileptic activity detected on routine electroencephalography (EEG) prior to TMS initiation.
• Routine pre-TMS laboratory tests reveal no abnormalities that may significantly affect treatment response, including:
• Normal thyroid hormone profile
• No significant vitamin deficiencies
• No markedly elevated inflammatory markers
• No history or current evidence of hearing loss on clinical evaluation; if present, evaluation by an otolaryngologist will be obtained.
• Age 18 years and older.
• Ability to provide written informed consent.

Exclusion criteria

• Any contraindication to TMS as identified in the standardized pre-TMS risk assessment form.
• Presence of epileptic focus detected on pre-TMS EEG.
• History of significant head trauma, loss of consciousness, or intracranial surgery.
• Presence of metal implants or foreign bodies incompatible with TMS (e.g., aneurysm clips, surgical clamps, metallic fragments).
• Abnormal thyroid hormone levels in pre-TMS laboratory testing.
• Significantly elevated inflammation markers (e.g., CRP) in pre-TMS bloodwork.
• Vitamin deficiencies associated with cognitive impairment (e.g., B12, folate) in pre-TMS labs.
• Electrolyte imbalances on pre-TMS blood testing.
• History of psychotic disorder or bipolar I/II disorder.
• History of substance-induced psychosis or bipolar disorder.
• Current or past substance use disorder (including alcohol, stimulants, or illicit drugs), unless abstinent from substances (excluding alcohol) for a minimum of 12 months.
• Voluntary discontinuation of TMS during the treatment course.
• Any serious adverse event or unexpected clinical condition during treatment that necessitates discontinuation of TMS.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Diagnostic

Study locations

Turkey (Türkiye) · 2 centers

• Gulhane Training and Research Hospital — Ankara
• Gulhane Training and Research Hospital — Ankara

Identifiers

NCT: NCT07039370 · 2025/245 / 46418926

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗