The period between 1880 and 1913, commonly known as the fin de siècle, was a time of great social, political and industrial change, an era in which the Victorian man saw his position within his society, his workplace and his family home undergo a radical transformation. It was also a period of evolution within the realm of mental medicine, which saw the development of radical new treatments across Europe and America. The methods, discourses and ideologies that underpinned these novel practices played a key role in the conception of mental illness, as well as the reconfiguration of the curative practices employed in its management. This thesis seeks to explore the depiction both of mental illness and of these new remedial discourses within the popular fiction of the period. Focusing specifically on the presentation of male madness, it seeks to extend the growing number of studies on masculinity and insanity in the nineteenth century, by considering its position at this late point of the period. It also breaks new ground by studying the depiction in fin de siècle literature not of illness, but of treatments for disorder, an area that has been considerably neglected critically. Divided into chapters based on genre, this thesis examines the portrayal of various types of madness in middle class male literary characters, arguing for a distinctive link between social anxieties and mental breakdown. It also explores how the fictional text engages with the scientific advancements of the period in treating mental illness, the key role played by narrative in both the creation of the story and the creation of the cure, and the clear interrelation and reciprocal influence between psychology and fiction at the end of the nineteenth century.