The work begins with an extensive introduction by Democritus Junior, who surveys the universal folly and melancholy of mankind across all ranks, professions, and nations. Arguing that almost the entire world is mad and driven by idleness, ambition, and greed, the author sets out to anatomise the specific disease of melancholy to alleviate both his own and others' suffering. The text is methodically divided into partitions that systematically examine the causes, symptoms, prognostics, and cures of the malady. Burton provides a detailed physiological and psychological foundation, beginning with an anatomical digression on the body, humours, spirits, and faculties of the soul.
He proceeds to categorize the varieties of melancholy, distinguishing between transitory emotional states and fixed, clinical disorders. The causes are traced through divine, astral, hereditary, and environmental influences, as well as the abuse of the six non-natural things. Particular attention is given to the physical and mental symptoms, ranging from groundless fear and suspicion to severe delusions and despair. The treatise ultimately seeks to serve as a comprehensive guide for spiritual and physical healing, offering both medical remedies and philosophical consolation for the troubled mind.