Primary Motor Cortex Plasticity In Male Patients With Depression

Depressive disorders, which are associated with poor quality of life, are one of the common mental disorders. The cortical plasticity of patients suffering from depressive disorders is a hot research in recent years, and study of cortical plasticity provides theoretical foundation for treatment of depressive disorders.In this study, fifteen healthy men served as controls, who work in Ningbo Kangning Hospital, and fifteen depressive men were patients who were in hospital.High-frequency repetitive transcranial magnetic stimulation was used to investigate the plasticity of left primary motor cortex of both healthy and depressive men, and the relationship between severity of major depressive disorder and plasticity was explored.Besides, we also investigated the possible impact of antidepressants on the plasticity of depressive men. Rotary pursuit task was used to measure the difference of motor learning skill and visual-motor harmonization between healthy and depressive men.The results were as follows:(1) The difference of the motor-evoked potentials at 5, 10 and 30 min between healthy and depressive men had reached significant levels, and the motor-evoked potentials at 15min reached marginal significance.(2)Higher SDS score was accompanied with lower MEP value.(3)No significant correlation between the dose of antidepressants and MEP was found.(4) In the four tests of rotating point and number of probe fall from the rotating point, the depressive group and healthy group had not reached significant levels.The conclusions were as follows:(1)Depressed patients suffered worse cortical plasticity than healthy men.(2)The more severe depressive disorder was in depressed patients, the worse the impairment of plasticity of M1 was.(3)Antidepressants did not impact the plasticity of M1 of depressive men directly.(4)We found no significant difference of motor learning skill and visual-motor harmonization between depressive and healthy group. Our results revealed that depression was not accompanied with the impairment of rotary motor learning skill,which suggested that cortical plasticity,as well as rotary motor learning may share different physiological mechanisms.