Comparative study for effects of repetitive transcranial magnetic stimulation on cognitive function in unipolar depression

Abstract

Objective To investigate the effects of left dorsolateral prefrontal cortex with 10HZ , 80%motor threshold repetitive transcranial magnetic stimulation ( rTMS ) on the cognitive function in unipolar depression. Method Sixty-nine patients with unipolar depression were randomly assigned to either the real rTMS group or the sham rTMS treatment( the control group) ,all patients were given extended releasing venlafaxine. the cognitive function was evaluated using P300 and Repeatable battery for the assessment of neuropsychological status ( RBANS-immediate memory, visuospatial, language, attention, delayed memory, total score), Wisconsin card sorting test ( WCST-Right responses, Completed categories, Total errors , Preservative errors, Nonpreservative errors ). The depression severity was assessed with the 24-item Hamilton Rating Scale for Depression(HAMD-24). All of tests were examined before and after six weeks with thirty times rTMS. Results At the end of six weeks treatments, regarding the WCST,real rTMS group showed better improvement in the right responses than control group(33.23±10.29 vs 27.09 ± 9.82, F= 16. 116 , P= 0. 000), besides right responses, real rTMS group had better performance in the rest items than control group(F=4.862 ～ 17.758, P= 0.031 ～ 0.000) ;concerning the RBANS, real rTMS group was significantly superior to control group in total score( (88.83 ± 16.48 ) vs (78.85 ± 13.51 ), F= 8. 425,P = 0. 005 ), besides total score , the real rTMS group had better performance in some rest factors than control group (F= 10.088 ～20. 801, P=0. 002 ～0.000);real rTMS group showed better improvement in the amplitude of P3than control group( (8.27 ± 2.97 ) μV vs ( 7.37 ± 2.66) μV, F= 5. 838 , P=0.018 ) ;real rTMS group demonstrated better improvement in HAMD-24 than control group( (4.7 ±2.4)vs ( 11.2 ±5.1 ), F= 29.537, P=0. 000).Conclusion rTMS can significantly improve cognitive function and depressive symptoms with unipolar depression. Key words: Unipolar depression; Cognitive function; Repetitive transcranial magnetic stimulation