Disclosed are polymorphic forms of sodium benzoate with a X-ray diffraction pattern comprising characteristic peaks at a reflection angle 2 ? of approximately 5.9, 30.2, and 31.2 degrees； or a X-ray diffraction pattern comprising characteristic peaks at a reflection angle 2? of approximately 3.7,5.9, and 26.6 degrees.Also disclosed herein are methods of preparing the polymorphic forms of sodium benzoate and uses thereof in treating and/or reducing the risk for a neuropsychiatric disorder.
