Diffusion magnetic resonance imaging for treatment response prediction in schizophrenia spectrum disorders: A systematic review

A substantial portion of schizophrenia spectrum disorder (SSD) patients exhibit resistance to antipsychotic treatments, emphasizing the need for reliable treatment response biomarkers. Previous magnetic resonance imaging (MRI) studies have identified various imaging predictors in SSD. This study focuses on evaluating the effectiveness of diffusion MRI sequences, diffusion tensor imaging (DTI) and diffusion-weighted imaging (DWI), in predicting antipsychotic response in SSD patients. A systematic search for relevant articles was conducted in PubMed, Embase, Scopus, and Web of Science on February 11, 2024. Twelve studies involving a total of 742 patients were systematically reviewed. The baseline DTI/DWI biomarkers revealed significant associations with antipsychotic treatment response. Notably a consistent negative link was found between response and baseline fractional anisotropy (FA) in fronto-temporo-limbic white matter tracts, specifically the superior longitudinal fasciculus, providing moderate-level evidence. In addition, weak-level evidence was found for the negative association between the treatment response and baseline FA in the corpus callosum, internal, and external capsule tracts. Collectively, this review demonstrated that obtaining pre-treatment brain diffusion MRI scans, particularly from white matter tracts of fronto-temporo-limbic network, can assist in delineating the treatment response trajectory in patients with SSD. However, additional larger randomized controlled trials are required to further substantiate these findings.