Co-occurrence Of Schizo-obsessive Traits And Its Association With Executive Function And Executive Control Network:An Exploratory Study

Empirical findings suggest that there is an overlap between schizophrenia and obsessive compulsive disorder(OCD).At the same time,these two disorders also have high comorbidity rate.Recent imaging findings also suggest that patients with schizophrenia and OCD exhibit executive dysfunction and altered resting-state functional connectivity(rs FC)within executive control network(ECN).However,very little is known about the executive functions and brain imaging data in subclinical samples of these two clinical groups,i.e.,individuals with schizotypal traits(SPT)and obsessive-compulsive traits(OCT).In particular,little is known about the impact of co-occurring SPT and OCT on executive functions and the corresponding altered rs FC.The present dissertation aimed to specifically examine these issues.Study 1examined the prevalence of coexisting schizotypal and obsessive compulsive traits in a sample of healthy college students.We also conducted a moderation analysis to explore the effect of these two traits on executive function.We recruited 3119 participants to complete the Schizotypal Personality Questionnaire(SPQ)and the Obsessive–Compulsive Inventory-Revised(OCI-R).A subset of them(n = 575)also completed the Chinese versions of the Dysexecutive Questionnaire(DEX).The findings showed that the prevalence of co-occurring schizotypal and OCD traits was 3.33%.Both traits had a negative impact on executive function.There was also an interaction between the disorganization dimension of schizotypal traits and OCD traits,which had a significant moderating effect on executive function.Study 2 aimed to explore the performance difference of executive function in 33 individuals with high SPT,26 individuals with high OCT,32 individuals with high schizo-obsessive traits(SOT),and 31 individuals with low traits(LT).We administered the Hayling Complement Sentence Test(HCST),the Six-Element Test(SET)and the Sustained Action to Response Task(SART)to measure specific components of executive functions.Moreover,all the participants needed to complete a self-reported Dysexectuive Questionnaire(DEX).We also conducted a moderating analysis to explore the effect of SPT and OCT on executive function behavioral performance in high SOT group.Our findings showed the high SOT and high SPT group did not exhibit impairments in all the executive function behavioral tests.However,the high SOT group reported increased scores of DEX compared with the other three groups.The high SPT group also reported increased DEX scores compared with the LT group.Moreover,the high OCT group exhibited significantly higher number of error ‘b’(disinhibition in semantic performance)and the total errors in the HCST compared with the LT group and the high SPT group.Moderation analysis showed that SPQ scores moderated the relationship between OCI-R scores and the number of error ‘a’(inhibition ability)of the HCST in the high SOT group.Study 3 examined the ECN-related functional connectivity and its relationship to behavioral executive functions in individuals with high SPT,high OCT,high SOT,and individuals with LT.We recruited 30 high SPT,25 high OCT,29 high SOT and 29 LT to undergo the resting state imaging scans.All the participants also completed a go/shift/no go task after the brain scan.Our findings showed the high OCT group exhibited significantly better shift ability(decreased shift reaction time and increased shift accuracy rate)than the high SOT group.Compared with the LT group,the high SOT group exhibited increased functional connectivity within the ECN,while the high SPT group exhibited decreased functional connectivity within the ECN.Moreover,the high OCT group exhibited decreased functional connectivity within the ECN and between the ECN and the default mode network(DMN)compared with the LT group.Correlation analysis showed that increased functional connectivity within the ECN correlated positively with the go reaction time in the high SOT group,decreased functional connectivity within the ECN correlated negatively with the shift reaction time in the high SPT group,and decreased functional connectivity between the ECN and the DMN correlated positively with the shift accuracy rate in the high OCT group.In conclusion,these findings suggest that there is an approximately 3% rate of co-occurring high ST and OCT in a college student sample.Regarding the performance of executive functions,individuals with high SOT reported more abnormal behaviors and had no behavioral test deficit compared with the other three groups.The functional imaging data suggested that individuals with high SOT exhibited increased functional connectivity within the ECN compared with the LT group,and also correlated with reduced executive function.However,individuals with sole high SPT and sole high OCT exhibited decreased connectivity within the ECN compared with the LT group.