We also evaluated the external validity of the SVC and SVR models by implementing the following procedures. Firstly, we examined whether the ReHo classifier features in data set 1 could effectively differentiate individuals with AUD from HCs in an independent dataset. Subsequently, without any model fitting, we applied the SVC model trained on data set 1 to an independent sample comprising patients with AUD and HCs. Secondly, we evaluated whether the ReHo predictor feature in data set 1 could effectively predict addiction severity (as measured by AUDIT and MAST scores) in individuals with AUD within the independent dataset. The SVR model, trained using the initial dataset, was directly applied to data set 2 without any additional model fitting.
