Altered Effective Connectivity in Reward-Related Circuits of Psychogenic Erectile Dysfunction: Insights From Spectral Dynamic Causal Modeling.

Psychogenic erectile dysfunction (pED) is a prevalent form of erectile dysfunction in younger men and is strongly linked to mood disturbances such as anxiety and depression. While previous functional connectivity studies have reported abnormal interactions in cortical and subcortical networks, the causal architecture of the reward circuit in pED remains poorly understood. In this study, we applied spectral dynamic causal modeling (spDCM) to resting-state fMRI data from 27 patients with pED and 31 matched healthy controls to investigate alterations in effective connectivity within the reward circuit. At the group level, parametric empirical Bayes and Bayesian model reduction identified 14 connections that survived a stringent posterior probability threshold (PP > 0.99). Correlation analyses revealed three robust associations after false discovery rate correction: stronger vmPFC-PCC connectivity was negatively correlated with erectile function, while reduced LAI-RAI connectivity and increased LAI self-connectivity were associated with depressive symptoms. These findings suggest that abnormal interactions among default mode, salience, and reward networks may underlie both sexual dysfunction and comorbid mood disturbances in pED. Our results highlight candidate neural pathways that may inform mechanistic understanding and guide future therapeutic strategies, while emphasizing the need for replication in larger samples.