Abstract: Phosphorus-31 magnetic resonance spectroscopy (³¹P MRS) enables the noninvasive assessment of cerebral high-energy phosphates, membrane phospholipid metabolites, and intracellular pH. When combined with magnetization transfer techniques, it can also evaluate enzyme-catalyzed reaction kinetics, providing a unique tool for investigating mitochondrial dysfunction, impaired energy metabolism, and abnormal membrane phospholipid turnover in psychiatric disorders. Conventional ³¹P MRS, including phosphorus-31 magnetic resonance spectroscopic imaging (³¹P MRSI), are limited by low signal-to-noise ratio, insufficient spatial resolution, and time-consuming acquisitions. Recent advances in ultra-high-field magnetic resonance imaging, multichannel radiofrequency coils, rapid spatial-spectral encoding, and advanced reconstruction methods have improved acquisition efficiency and quantitative capability. This review summarizes the basic principles, acquisition and quantification methods, and applications of ³¹P MRS/MRSI in major psychiatric disorders, and discusses potential sources of heterogeneity across studies. Future work should further advance absolute quantification, dynamic metabolic measurements, multicenter standardization, and large-scale longitudinal studies.

Key words: 31P MRS, 31P MRSI, psychiatric disorders, energy metabolism, magnetization transfer spectroscopy