The Dichotic Listening Research For Different Chinese Rhyming Words In Major Depressive Disorders (MDD) By Focused Attention

Objective: to compare the brain function asymmetry characters between patients with MDD and healthy controls, and whether there are differences between MDD with or without a comorbid with anxiety disorder, between different levels of education, and between before and after drug administer. Method: The study examined the ear advantage of 58 healthy subjects, 115 patients with MDD using two kinds of rhyming words by the method of focused attention, and 34 patients in the MDD group were examined again after taking drugs six weeks later. Results: 1.In healthy group, no ear advantage was found in true words test, but appeared significant right ear (left-hemisphere) advantage in pseudo-words test. 2.In MDD group, there was no ear advantage in true words test, but enhanced right ear (left-hemisphere) advantage in pseudo-words test, there was a significant difference between the MDD and healthy subjects. 3. In true words test, no ear advantage was found in MDD with a comorbid anxiety disorder; but in without a comorbid anxiety disorder, In pseudo-word test, two groups appeared right ear (left-hemisphere) advantage, and that the right ear(left-hemisphere) advantage in the group of MDD without anxiety disorders was larger than that of group of MDD with anxiety disorders, there was a significant difference between this two groups.4.There were no differences in true words test among the level of education; the right ear (left-hemisphere) advantage in the group of lower education was larger than that of higher education group in pseudo-words tests. 5. HAMD, KAMA and SCL-90 ratings correlate significantly with neither asymmetry scores of true words nor that of pseudo-words. 6.There were no differences between before and after drug administer in ear advantage in the group of MDD. Conclusions: 1 .There is no ear advantage for process and cognition of true words but as for that of pseudo-words appear right ear (left-hemisphere) advantage in healthy Chinese. 2.Patients with MDD have a greater right ear (left hemisphere) advantage for Chinese words processing than healthy subjects. 3.The patients with or without a comorbid anxiety disorder have a larger right ear (left-hemisphere) advantage for Chinese words processing than those of healthy subjects, and patients without a comorbid anxiety disorder appear larger than those of patients with a comorbid anxiety disorder. 4.Patients of lower education appear larger right ear (left-hemisphere) advantage than that of higher education. 5.Asymmetry scores don't correlate significantly with scale scores. 6.The pseudo-words is the better choice as stimuli for dichotic listening test.