Exploring the mechanism of the electroacupuncture treating the generalized anxiety disorder using fMRI

INTERVENTION: healthy group:none;Treatment group:transcutaneous auricular vagus nerve stimulation;control group:stimulation of Scaphoid part of upper ear ; CONDITION: generalized anxiety disorder PRIMARY OUTCOME: HAMA‐17;fMRI; SECONDARY OUTCOME: HAMD‐24;SDS;SAS; INCLUSION CRITERIA: 1. DSM‐5 diagnostic criteria for generalized anxiety disorder of mental disorders in the United States 2. The 17 item score of Hamilton Anxiety Scale (HAMA): 29> score = 7 3. Age 18‐70 4. Right handedness 5.Those who have not used anti anxiety drugs (including western medicine and traditional Chinese Medicine) and other psychotropic drugs 2 weeks before treatment, or those who have used but have stopped for 2 weeks 6. Education level above junior high school