Monoamine Oxidase A (MAO‐A) Genetic Variants in Psychopathic Disorders and Their Impact on Brain Structure and Function

The study of psychopathic disorders, which refers to both psychopathy and antisocial personality disorder (ASPD), has benefited from a rich array of neuroimaging and molecular genetic studies seeking to elucidate the neural underpinnings of these conditions and their symptom clusters. One genetic marker that has captivated the interest of researchers is monoamine oxidase A (MAO-A). The reason for this attention relates to the fact that MAO-A genetic polymorphisms have been associated with psychopathic disorders at the group level, and they also show a relation with altered neuroimaging findings in ASPD and psychopathy. This chapter provides a general overview of the structure and function of MAO-A to provide the unfamiliar reader with the necessary background information. It also provides a review of extant studies implicating MAO-A genetic variants in the pathophysiology of psychopathic disorders. The chapter discusses the emerging evidence base connecting MAO-A genetic polymorphisms with structural and functional brain changes.