What is background information?
Background information, or reference information, is the type of information you could get from Wikipedia. These resources will give you trustworthy overviews of a topic and provide you with basic things like dates, events and facts about your topic. Generally, you can think of this information in terms of the who, what, where and when of a topic.
Diagnostic and Statistical Manual of Mental Disorders - 5
The Diagnostic and Statistical Manual of Mental Disorders (DSM) is the handbook used by health care professionals in the United States and much of the world as the authoritative guide to the diagnosis of mental disorders. DSM contains descriptions, symptoms, and other criteria for diagnosing mental disorders.