Objective To analyze the influence of low-frequency repetitive transcranial magnetic stimulation (rTMS) combined therapy on mismatch negativity (MMN) and contingent negative variation (CNV) in patients with Parkinson's disease complicated with depression.

Methods Seventy patients with Parkinson's disease complicated with depression admitted to Suzhou Hospital Affiliated to Anhui Medical University in 2024 were selected as the patient group, and divided into the rTMS combination group and simple medication group according to the random number table method, with 35 cases in each group. Additionally, 20 healthy individuals who underwent physical examinations at Suzhou Hospital Affiliated to Anhui Medical University during the same period were selected as the control group. The simple medication group was given citalopram tablets at a dose of 20 mg/d, and the rTMS combination group was treated with the same dosage of citalopram combined with low-frequency rTMS on the dorsolateral right frontal lobe for 12 weeks. Before and after the treatment, the Hamilton Depression Scale (HAMD-17) score, MMN and CNV in patients were detected. The general information and examination indicators among three groups were compared.

Results After 12 weeks of treatment, the HAMD-17 scores in patient group decreased (P ＜ 0.05), and the HAMD-17 score decreasing in the rTMS combination group was more significantly than that in simple medication group (P ＜ 0.05). Before treatment, the latency of MMN and CNV in patient group was longer than that in control group (P ＜ 0.01), and the amplitude of CNV was lower than that in control group (P ＜ 0.01). After 12 weeks of treatment, the latency of MMN in the patient group shortened (P ＜ 0.05), the latency of CNV shortened (P ＜ 0.05), and the amplitude increased (P ＜ 0.05). Moreover, the shortening of MMN and CNV latency in the rTMS combined group were more significant than that in simple medication group (P ＜ 0.05), and the increasing of CNV amplitude was more significant than that in simple medication group (P ＜ 0.05).

Conclusions Both citalopram and citalopram combined with rTMS can have therapeutic effects on Parkinson's disease complicated with depression, and the latter is superior to the former. The combination of rTM can further improve the mental symptoms of patients.