For more background on diseases and to help you generate search terms, it can be beneficial to find secondary sources discussing the epidemiology and historical context of specific diseases. The following sources can help you get started.
The Cambridge World History of Human Disease by Kenneth F. Kiple (Editor)
Combining recent medical discoveries with historical and geographical scholarship, this is the most comprehensive history of human disease since August Hirsch's monumental Handbook of Geographical and Historical Pathology in 1880. Accessible to laypeople and specialists alike, The Cambridge World History of Human Disease explores the patterns of disease throughout the world as well as the variety of approaches that different medical traditions have used to fight it. The volume traces the concept of disease as medicine developed from an art to a science, then addresses the history of disease in each major world region. The final and largest part offers the history and geography of each significant human disease - both historical and contemporary - from AIDS to yellow fever. A truly interdisciplinary history, it includes contributions from over 160 medical and social scientists from across the globe. Together with The Cambridge World History of Food (2000), The Cambridge World History of Human Disease provides an extraordinary glimpse of what is known about human health as the twenty-first century begins.
Arranged in the same sequence as the DSM-5, this reference tool covers what has changed from the DSM-IV, what the change means for diagnosis, and the implication of these changes on the selection of effective, evidence-based treatment. Reichenberg also covers the major changes to the DSM-5 such as the replacement of the multi-axial system, the developmental and lifespan approach, and cultural and gender considerations.