“Depression”[mesh] describes a related-but-separate concept from “Depressive Disorder”[mesh], and they live on different branches of the MeSH tree. Functionally however, Depressive Disorder ends up being a narrower heading of Depression:
How much overlap would you expect between “Poisoning” the MeSH heading and “/poisoning” the subheading? It makes sense that they would be at least a little different, given the admonishment in the annotation to “prefer /pois with Category D & J terms”. Would it surprise you to find that they overlap by a little less than a third?
Lastly, I was reminded that subheadings, just like other descriptors, can be broad or narrow (and that the broad ones are exploded by default). This diagram isn’t so much revelatory as it is just pretty…