Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies are currently being investigated in animal models and clinical studies. However, very little is currently known about the mechanisms that deregulate BDNF gene expression in these disorders. The BDNF gene structure and tissue expression pattern is complex, controlled in humans by 9 different gene promoters. Recently, epigenetic changes at the BDNF gene locus have been proposed to provide a link between gene and environment. In this review, we will summarize the current knowledge of BDNF epigenetic regulation with respect to psychiatric disorders and describe how this information can be applied in therapy and future research.