81. Relationship Between Untreated Psychosis and Intrinsic Corticostriatal Connectivity in Patients With Recent-Onset Schizophrenia
Year: 2017
Type: article
Abstract: Background: Patients with first-episode psychosis experience psychotic symptoms for a mean of up to 2 years prior to initiation of treatment, and long duration of untreated psychosis (DUP) is associated with poor clinical outcomes. Meanwhile, evidence compiled from numerous studies suggests that longer DUP is not associated with structural brain abnormalities. To date, few studies have examined the relationship between DUP and functional neuroimaging measures. In the present study, we used seed-based resting-state functional connectivity to examine the impact of DUP on corticostriatal circuitry. Methods: We examined patients with first-episode schizophrenia who underwent resting state scanning prior to entering 12 weeks of prospective treatment with second-generation antipsychotic drugs. DUP was quantified based on interviews with patients and their families. Patients were followed during treatment and response to treatment was defined, a priori, based on minimal psychotic symptom items of the Brief Psychiatric Rating Scale. We generated functional connectivity maps from 6 regions of interest (ROIs) within the striatum in each hemisphere. Group level analyses were performed for each ROI, independently, with log transformed DUP as a covariate. Significance was defined at P <0.05, cluster corrected. Post-hoc mediation analyses were performed on a composite measure of corticostriatal connectivity derived from the significant results of our DUP analysis. Results: We included 85 patients in our analyses (mean age 21; 61 males, 24 females), who had a mean DUP of 102 weeks (SD=77; median=35 weeks). We found that increased DUP correlated with decreased functional connectivity between striatal nodes and frontal and parietal regions, some of which are within the central executive network. In post hoc analyses, a primary explanatory factor within these significant connections showed a mediation effect between DUP and treatment response. Conclusion: Our results indicate that variation in corticostriatal circuitry may play a role in the relationship between longer DUP and worsened response to treatment. Future prospective studies are necessary to further characterize potential causal links between DUP, striatal circuitry and clinical outcomes.
Source: Schizophrenia Bulletin
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2603174010