Effects of tDCS on Fear Reversal in Patients With Anxiety Disorders

Официальное название

A Randomized, Double-Blind, Controlled Study of Transcranial Direct Current Stimulation Intervention on Fear Reversal in Patients With Anxiety Disorders

Обзор

This study evaluates the effects of single-session Transcranial Direct Current Stimulation (tDCS) on fear reversal learning in patients with anxiety disorders. Participants will be randomized into four groups to receive either active stimulation targeting specific brain regions (right DLPFC or vmPFC), an active control stimulation, or sham stimulation. The main goal is to determine if modulating these brain areas can improve the ability to update safety and threat associations.

Подробное описание

Anxiety disorders are characterized by deficits in fear regulation and cognitive flexibility, specifically the inability to inhibit fear responses when a threat becomes safe (fear reversal). Neurobiological models suggest this is linked to hyperactivity in the right dorsolateral prefrontal cortex (rDLPFC) and hypoactivity in the ventromedial prefrontal cortex (vmPFC).

This randomized, double-blind, sham-controlled study aims to verify if tDCS can improve fear reversal performance. The study involves 140 patients with anxiety disorders assigned to one of four arms:

Cathodal tDCS over the right DLPFC (inhibitory); Anodal tDCS over the vmPFC (excitatory); Sham tDCS (placebo); Anodal tDCS over the left DLPFC (active control). During the 25-minute stimulation session, participants will perform a computerized fear reversal task. Physiological data (Skin Conductance Response) and subjective anxiety ratings will be recorded simultaneously to assess the intervention's impact on cognitive and emotional regulation.

Вмешательства

• Устройство Cathodal tDCS (rDLPFC)
  Current intensity: 2.0 mA. Duration: 25 minutes. Cathode placed over F4 (10-20 system), Anode over contralateral deltoid.
• Устройство Anodal tDCS (vmPFC)
  Current intensity: 2.0 mA. Duration: 25 minutes. Anode placed over Fpz (10-20 system), Cathode over Oz.
• Устройство Sham tDCS
  Current ramps up for 30 seconds and then fades to zero to mimic skin sensation, with no sustained current for the rest of the 25 minutes.
• Устройство Anodal tDCS (lDLPFC)
  Current intensity: 2.0 mA. Duration: 25 minutes. Anode placed over F3 (10-20 system), Cathode over contralateral deltoid.

Первичные конечные точки

• Mean Accuracy Rate in the Reversal Phase of the Fear Reversal Task [Срок оценки: During the intervention (Day 1, approximately 25 minutes)]

Вторичные конечные точки (3)

• Reaction Time in the Reversal Phase [Срок оценки: During the intervention (Day 1, approximately 25 minutes)]
• Skin Conductance Response (SCR) Amplitude [Срок оценки: During the intervention (Day 1, approximately 25 minutes)]
• Subjective Anxiety Score (VAS) [Срок оценки: During the intervention (Day 1, assessed intermittently during the 25-minute task)]

Критерии участия

Критерии включения

Age between 18 and 60 years old. Right-handed. Meeting the DSM-5 diagnostic criteria for Gambling Disorder (GD). South Oaks Gambling Screen (SOGS) score ≥ 5. Normal or corrected-to-normal vision and hearing. Willingness to provide written informed consent and participate in the study.

Критерии исключения

History of other severe psychiatric disorders (e.g., schizophrenia, bipolar disorder, severe depression) or neurological diseases (e.g., epilepsy, stroke, brain tumor).

History of substance abuse or dependence (excluding nicotine) in the past 6 months.

Current use of psychotropic medications that may affect cortical excitability (e.g., antidepressants, antipsychotics, anticonvulsants).

Presence of metallic implants in the head or neck area (e.g., cochlear implants, aneurysm clips) or cardiac pacemakers.

Skin lesions or sensitivity at the stimulation sites on the scalp. Pregnancy or lactation. Participation in other neuromodulation studies within the last 3 months.

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Да

Дизайн исследования

Распределение

Рандомизированное

Модель

Параллельные группы

Маскирование

Тройное слепое

Основная цель

Лечение

Центры проведения

Китай · 1 центр

• Shenzhen Kangning Hospital — Гуанчжоу

Идентификаторы

NCT: NCT07405463 · KN2025407

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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