Transcranial Direct Current Stimulation (tDCS) and Immersive Virtual Reality Meditation (IVRM) for the Treatment of Anxiety Disorders

Transcranial Direct Current Stimulation (tDCS) and Immersive Virtual Reality Meditation(IVRM) for the Treatment of Anxiety Disorders: A Randomized Controlled Trial

The goal of this RCT is to evaluate the post-intervention (week 2) and 1-month post-intervention (week 6) of a 2-week intervention (12 sessions) of combined tDCS (a non-invasive brain stimulation method, with anodal stimulation over lDLPFC and cathodal stimulation over rDLPFC) and immersive virtual reality meditation (IVRM) on anxiety severity among individuals with anxiety disorders, as compared to sham group. We also assess the effects of the intervention on other secondary outcomes as compared to sham group, as well as the tolerability (how well people can handle it) and feasibility (how easy it is to carry out) of this combined intervention.

Exploratory analyses will examine physiological markers, such as heart rate variability (HRV), in relation to treatment response.

Participants will receive total 12 sessions of either active or sham tDCS on DLPFC paired with IVRM. The assessment will be blinded to assessors. No one (participants, researchers, assessors) will be revealed the group allocation. Sham tdcs applies the standard blinding protocol with 30 seconds of ramping up and ramping down periods.

Participants will:

Receive 12 total treatment sessions (twice a day for 2 weeks); each session is 20 minutes of tDCS (active or sham) plus IVRM. The IVRM uses HypnoVR® with 3D scenes (e.g., beach, forest) and 20-minute guided scripts meditation.Take a 20-minute break between the two daily sessions.

Complete assessments at three time points: baseline (before treatment, T0), right after the 2-week treatment (T1), and 1 month after treatment (T2). Assessments include anxiety tests (e.g., HAM-A, Beck Anxiety Inventory), adverse effect questionnaires (for tDCS and IVRM), and physiological checks (e.g., heart rate variability).

Inclusion Criteria:

• Aged 16-70 years;
• Diagnosed with Generalized Anxiety Disorder (GAD) or Mixed Anxiety and Depressive Disorder (MADD) or Major Depressive Disorder with prominent anxiety symptoms, according to the Structured Clinical Interview for DSM-5, Clinical Version (SCID-DSM-5, CV)
• Scored ≥ 8 (i.e., at least mild to moderate anxiety on the 14-item Hamilton Anxiety Rating Scale (HAM-A)) at screening;
• Right handedness;
• Stable dosage of antidepressants or other treatments for depression in recent 4 weeks; and
• Can read and write Chinese

Exclusion Criteria:

• History of significant head trauma, neurological disorders (e.g., epilepsy), seizures, or focal brain lesions;
• First degree relative with epilepsy, significant neurological illness or head trauma, endocrine disease;
• Concomitant unstable medical condition or major neurological conditions;
• Comorbid disorders listed in the DSM-V, e.g., schizophrenia, mental retardation, etc.;
• Current or history of alcohol or drug abuse;
• Inability to provide informed consent