The Study About Affective Psychosis Task Switching

Objective There are many affective psychosis patients in hospital, include bipolar-disorder, maniac, depression. The core symptoms of maniac and depression episodes are flight of thought and inhibition of thought. Flight of thought refers to associative thinking quickly, inhibition of thought presented thinking and reacting slowly. From a phenomenological point of view, their cognitive flexibility are questionable, and cognitive abilities in patients with mania are better than depression. To confirm this hypothesis, this study used task-switch paradigm to explore manic episodes and depressive episodes about cognitive flexibility differences.Methods Thirty-one patients who met ICD-10 diagnosises for Manic or Bipolar affective disorder without psychotic symptoms as one patient group, thirty patients who met ICD-10 diagnosises for depression or Bipolar affective disorder currently moderate depressive episode as another patient group, and fifteen healthy control group subjects matched for age, gender, education were assessed by a neuropsychological tests including Digit Span Test(DST) and Verbal Fluency Test(VFT). At the same time uesing Bech-Rafaelsen scales assess manic performance and HAMD scals assess depressive disoders. Then all subjects take task cueing paradigm. The experiment consists of three parts: the first part is odd-even single-task block, the second part is big-small single-task block, the third part is mixed task block consist odd-even judgment and lager than big-small tasks.Results 1:There were significant differences between two patient groups and control group on DST and VFT tasks(P﹤0.01), the control group is better than manic group(P<0.01)and depressive group(P<0.01),but not between manic group and depressivegroup(P>0.05).2:On odd-even and big-small tasks, the switch cost have significant differences between three groups(P﹤0.05),the control group is less than manic(P﹤0.05)and depressive group(P﹤0.05),but not between manic group and depressive group(P>0.05);3:There are not significant differences about RT and ER mixing cost between three groups on odd-even task(P>0.05), but on big-small task RT mixing cost have significant differences(P﹤0.05), the control group is less than manic group(P﹤0.05)and depressive group(P﹤0.05),but not between manic group and depressive group(P>0.05).4:There are significant correlation between education years, disease course and neuropsychological test scores, the frontal verbal fluency is correlated with response time of switching task(P﹤0.05 or P﹤0.01).Conclusion There are some problems in affective psychosis patients about cognitive flexibility. About switch cost, two patient groups are lager than the control group,but not between manic group and depressive group. About mixing cost, there are not significant differences between the three groups. Impaired cognitive flexibility is associated with prefrontal cortex function.