Abnormal Neural Activities In Patients With Obsessive-Compulsive Disorder And Its Potential In Building Models For Diagnosis And Prediction Of Early Treatment Effect

Aim: To reveal the early functional brain changes induced by pharmacotherapy in patients with obsessive-compulsive disorder(OCD)in relation to drugs per se or the impact of such drugs on the improvement of OCD and to explore potential neuroimaging biomarkers for OCD diagnosis and prediction of early treatment response.Methods: At baseline(0 day),all participants underwent resting state functional magnetic resonance imaging,and their general information was collected.Subsequently,patients with OCD received paroxetine treatment for 5 weeks(40 mg/day)and were scanned again after the5-week treatment(endpoint=5 weeks).Clinical symptoms of the patients with OCD were assessed at baseline and post-treatment.Parameters,namely,regional homogeneity(Re Ho),fractional amplitudes of low-frequency fluctuations(f ALFF),and voxel-mirrored homotopic connectivity(VMHC)were applied to measure the spontaneous neural activities.Support vector machine(SVM)and support vector regression(SVR)analysis were used to explore the modals for diagnosis and prediction of the early treatment effect.Results: Thirty-four patients with OCD and 36 healthy controls(HCs)were included in the final analysis.Twenty-four among the 34 patients with OCD completed the 5-week follow-up.The treatment duration of patients with OCD who completed the follow-up was 34 ± 5days.After the 5-week treatment,patients with OCD showed significantly clinical improvement relative to their baseline assessments.Compared with HCs,patients with OCD had abnormal Re Ho,f ALFF,and VMHC values in extensive brain regions and networks such as the hippocampal-cortical system,default mode network,sensor-motor network,and visual network.Abnormal baseline f ALFF values in the left precuneus/ posterior cingulate cortex(PCC)(r =-0.526,p = 0.001)and right middle cingulate cortex(MCC)(r =-0.588,p < 0.001)were negatively correlated with the scores of compulsions assessed at baseline.SVM analysis showed that the Re Ho values of the bilateral hippocampus/parahippocampus/fusiform gyrus/cerebellum,f ALFF values of the right precentral gyrus and right MCC,or VMHC values in the superior parietal lobule and postcentral gyrus at baseline could serve as potential neuroimaging features for classification.Re Ho values in the left hippocampus/parahippocampus decreased significantly after treatment.The reduction rate(RR)of Re Ho values was positively correlated with the RRs of the scores of Yale-Brown Obsessive-Compulsive Scale(r = 0.407,p=0.049)and obsession(r = 0.422,p = 0.040).SVR analysis showed that the Re Ho values of the left hippocampus/parahippocampus/fusiform gyrus/cerebellum,the f ALFF values of the left precuneus/PCC and right MCC,or VMHC values of the postcentral gyrus at baseline could serve as potential neuroimaging features for prediction of early treatment effect.Conclusions: Patients with OCD had abnormal spontaneous neural activities in extensive brain regions and networks which might partly explain the nature of OCD.When patients with OCD treatment with selective serotonin reuptake inhibitors(SSRIs),the treatment-induced early functional brain changes might be related to the treatment effects rather than the drugs per se or the side effects.In the early stages of treatment with SSRIs,the remission of OCD symptoms may result from the improvement of anxiety.It is possible to build models for diagnosis and prediction of early treatment response based on spontaneous neural activities in patients with OCD at baseline.