To investigate the effect of Temporal Interference Stimulation (TIS) on associative memory (AM) in patients with depressive disorder

Depression group: thirty patients with depressive disorder diagnosed by DSM-5 were recruited from the Second Affiliated Hospital of Anhui Medical University. All participants underwent a structured interview and routine laboratory examination before and after receiving TIS treatment. After meeting the inclusion criteria and obtaining informed consent. Each patient received either 30-minute or sham TIS.

Before and after the treatments, the patients had received a battery measure of neuropsychological tests, and MRI scan in multimodalities. Neuropsychological assessment included HAMD, ANSAQ, HAMA, PHQ15, BSSI, PSQI, ISI, RRS, Barratt,Buss&Perry and PVAQ. Multimodal MRI includes 3D-T1, rs-fMRI, and DTI.

Healthy controls: thirty healthy participants, who met the same exclusion criteria as the depressed patients but without a diagnosis of depression, were matched to the patients in terms of age, sex, and years of schooling.

The incidental memory task with emotional pictures were applied to evaluate the associative memory (AM) of thirty depressed patients at pre- and post-TIS compared to thirty healthy controls.

Inclusion Criteria:

• the patients were diagnosed by more than 2 psychiatrists and met the diagnostic criteria of DSM-5 for depression, and HAMD>17, BSS>6, PHQ-15>5.
• 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