Intervention Effect of High Definition Transcranial Alternating Current Stimulation (HD-tACS) on Depressive Disorder

Intervention Effect of High Definition Transcranial Alternating Current Stimulation (HD-tACS) on Depressive Disorder

To investigate the intervention effect of high definition transcranial alternating current stimulation (HD-tACS) on suicidal ideation in patients with depressive disorder and its underlying neural mechanism by magnetic resonance imaging (MRI) and electroencephalography (EEG).

Forty patients with depressive disorder diagnosed by DSM-5 were recruited from the Anhui Mental Health Center and the first affiliated Hospital of Anhui Medical University. All participants underwent a structured interview and routine laboratory examination before and after receiving high definition transcranial alternating current stimulation (HD-tACS) treatment after meeting the inclusion criteria and obtaining informed consent. Each participant will complete the clinical evaluation, magnetic resonance imaging (MRI), electroencephalography (EEG), and HD-tACS treatment conducted by trained researchers at the Anhui Mental Health Center. All the participants were randomized (1:1) to receive an "active HD-tACS" or "sham HD-tACS" treatment protocol. tACS: the central electrode was placed over F3 with return electrodes placed at Fp1, Fz, F7 and C3. Fourteen 2-mA sessions (ramp-up and ramp-down periods of 15 and 15 seconds, respectively) were applied for 30 minutes per session, twice daily over 7 consecutive days, and the stimulus frequency was set as individual alpha frequency (IAF). Sham HD-tACS 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 15 and 15 seconds.

Before and after the treatments, the patients received a battery measure of neuropsychological tests, resting EEG, and MRI scans in multimodalities. The neuropsychological assessment included HAMD, MADRS, BDI, HAMA, BSS, C-SSRS, PHQ15, RRS, TEPS, PVAQ, MoCA, Stroop Test, VFT, DST, and AVLT. Multimodal MRI includes 3D-T1, rs-fMRI, and DTI. The symptoms of the patients were followed up one and two months after the end of treatments.

Inclusion Criteria:

• the patients were diagnosed by more than 2 psychiatrists and met the diagnostic criteria of DSM-5 for depression, and item 3 of the HAMD≥3.
• the age ranged from 18 to 65 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