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This page is an AI-assisted Turkish summary of the study presented at the 26th World Congress of Psychiatry. The study belongs to the presenting authors; please refer to the original source when citing it.

Reorganization of prefrontal resting-state functional connectivity following ISTDP-based psychotherapy in treatment-resistant depression: a graph theory study

Prefrontal resting-state functional connectivity reorganization following istdp-informed psychotherapy in treatment-resistant depression: a graph-theory

In treatment-resistant depression, 10 weeks of ISTDP-based psychotherapy was associated with symptom improvement and reorganization of prefrontal network topology measured using fNIRS.

The study aimed to investigate whether 10 weeks of psychodynamic psychotherapy based on Intensive Short-Term Dynamic Psychotherapy (ISTDP) was associated with changes in prefrontal resting-state functional connectivity (RSFC) in treatment-resistant depression (TRD). Fifteen patients with TRD were enrolled, two dropped out, and 13 patients with TRD and 16 healthy controls (HC) remained; the TRD group received psychotherapy, while controls underwent repeated assessments without intervention. Five-minute recordings of prefrontal RSFC were obtained at baseline and week 10 using a 48-channel functional near-infrared spectroscopy (fNIRS) system. HbO2 signals underwent motion correction and band-pass filtering (0.009 to 0.08 Hz); global, intrahemispheric, and interhemispheric connectivity and region-of-interest-to-region-of-interest (ROI-to-ROI) measures between prefrontal Brodmann areas were calculated, and graph theory metrics derived from binarized networks (thresholds of 0.2 to 0.6) were summarized using the area under the curve (AUC). Depressive symptoms improved significantly in the TRD group without medication changes (HAM-D-17: from 21.38±3.04 to 13.15±6.26, p<0.001). Although baseline RSFC values did not differ between groups, significant group x time interactions emerged for global and hemispheric connectivity, and post-treatment differences remained significant after false discovery rate (FDR) correction; ROI analysis revealed a change in connectivity between the left dorsolateral prefrontal cortex (DLPFC) and the left orbitofrontal cortex (OFC) (uncorrected p<0.05). Network analyses detected no change in efficiency, but the clustering coefficient AUC decreased and the small-worldness AUC increased in the TRD group, while no longitudinal network changes were observed in controls. The findings suggest that ISTDP-based psychotherapy is associated with symptom improvement and reorganization of prefrontal network topology, and that portable fNIRS-based network measures may serve as feasible indicators of psychotherapy-related brain changes; however, these findings require replication in larger controlled studies.

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