The invention relates to sulphur- and/or selenium-containing compounds that can inhibit the enzyme inositol mono-phosphatase (IMPase), and which can be used in treating conditions that are treatable through inhibition of this enzyme, such as bi-polar disorder, the compounds having a structure of Formula (I), or is a pharmaceutically acceptable salt thereof; Formula (I); in which: E is S or Se and each of phenyl rings A and B is optionally substituted with one or more substituents, in which each substituent is selected independently from: (1) a halogen, which is preferably selected from F, Cl and Br; (2) C1-C4 alkyl, such as C1-C2 alkyl or C1 alkyl, optionally substituted with one or more halogen atoms, each of which is preferably selected from F, Cl and Br; and (3) C1-C4 alkoxy, such as C1-C2 alkoxy or C1 alkoxy; optionally substituted with one or more halogen atoms, each of which is preferably selected from F, Cl and Br.