Abstract: The disclosed subject matter provides certain polymorphic forms of Compound (I) as well as pharmaceutical compositions comprising Compound (I) or such polymorphic forms, and methods of using or making such compounds and pharmaceutical compositions. It has now been discovered that Compound (I) can exist in multiple crystalline forms (polymorphs). One particular crystalline form, Form II, has been found to be more thermodynamically stable and, thus, likely more suitable for bulk preparation and handling than other polymorphic forms. Efficient and economic methods have been developed to prepare Compound (I) and Form II in high purity on a large scale. In animal studies, Form II has demonstrated safety and efficacy in treating depressive disorders and, when micronized, improved absorption compared to non-micronized Form II.