Polymorph forms of (2S)-(4E)-N-methyl-5-[3-(5-isopropoxypyridin)yl]-4-penten-2-amine p-hydroxybenzoate, and methods for their preparation, pharmaceutical composition containing said polymorph(s) and use, are disclosed. The polymorphs can be administered to patients susceptible to or suffering from conditions and disorders, such as central nervous system disorders, to treat and/or prevent such disorders.