As VMATs are membrane proteins, structural information is limited and researchers have yet to completely understand the structure of both isoforms. Further studies are needed in order to determine the structure and therefore complete function of these proteins. There is preliminary evidence that the gene for VMAT1 may be linked to susceptibility to schizophrenia, bipolar disorder, and various anxiety disorders. Further studies are needed in order to confirm these findings and to gain a better understanding of the role of VMATs in the central nervous system.