Intervention Effect of High Definition Transcranial Direct Current Stimulation (HD-tDCS) on Anxiety Disorder

Intervention Effect of High Definition Transcranial Direct Current Stimulation (HD-tDCS) on Anxiety Disorder

To investigate the intervention effect of high definition transcranial direct current stimulation (HD-tDCS) on anxiety symptoms and somatic symptoms in patients with anxiety disorder and its underlying neural mechanism by MRI.

Anxiety is characterized by excessive fear, anxiety, or avoidance of a range of external and internal stimuli. Somatic symptoms often co-occur with anxiety and are part of the manifestation of anxiety. The purpose of this study was to explore the relieving effect of high definition transcranial direct current stimulation (HD-tDCS) on the symptoms of anxiety.

60 patients with anxiety disorder diagnosed by DSM-5 were recruited from the fourth people's Hospital of Hefei and the first affiliated Hospital of Anhui Medical University. All participants underwent a structured interview and routine laboratory examination before and after receiving HD-tDCS. After meeting the inclusion criteria and obtaining informed consent, each participant will complete the clinical evaluation, functional magnetic resonance imaging (fMRI) and HD-tDCS treatment conducted by trained researchers at the Neuropsychological Synergetic Innovation Center of Anhui Medical University. All the participants were randomized (1:1) to receive "active" or "sham" treatment protocol. The anode was placed over Fz with return electrodes placed at Fpz, Cz, F3 and F4. Fourteen 2-mA sessions (ramp-up and ramp-down periods of 30 and 30 seconds, respectively) were applied for 20 minutes each day over 14 consecutive sessions. Sham HD-tDCS was delivered using the same protocol and current intensity, but the period of active stimulation was only during the ramp-up and ramp-down periods of 30 and 30 seconds.

Before and after the HD-tDCS treatment, the patients had receiving a battery measure of neuropsychological tests and Magnetic resonance imaging scan in multimodalities. Neuropsychological assessment included MoCA, Stroop Test, VFT, DST, AVLT, HAMD, HAMA, PHQ15, BSS(Beck scale for suicide ideation),ISI,SDS, RRS, TEPS, AES, FPQ, PVAQ and AAS. Multimodal fMRI includes 3D-T1, rs-fMRI, DTI and ASL.

Neuropsychological evaluation and magnetic resonance imaging data were obtained again 24 hours after the last treatment. The symptoms of the patients were followed up one month after the end of treatment.They were instructed to focus their answers on the past week. Afterwards, they were unblinded by the study coordinator.

Inclusion Criteria:

• the patients were diagnosed by more than 2 psychiatrists and met the diagnostic criteria of DSM-5 for anxiety, and HAMA>14, PHQ-15>5.
• the age ranged from 18 to 60 years old, and the length of education was more than 5 years.
• the visual acuity or corrected visual acuity is normal, right-handed, can cooperate with the completion of various experimental tests.

Exclusion Criteria:

• accompanied by severe somatic diseases, such as severe heart, liver, renal insufficiency and so on.
• accompanied by other neurological diseases, such as stroke, epilepsy and so on.
• pregnant and lactating women.
• accompanied by other mental disorders, such as drug abuse, schizophrenia, schizophrenic affective disorder, hysteria, autism and so on.
• patients with MRI taboos or factors affecting imaging quality, such as cardiac pacemaker, cochlear implant, cardio-cerebrovascular metal stent, metal denture, etc.
• those who could not cooperate with those who completed the relevant experiments, such as patients with depressive stupor, claustrophobia and so on.