For the diagnostic criteria I’d try to use a memory palace with a room for all the points from A. to H. The room for B. should have enough space to put all 6 criterias there.
In front of the building, there could be an image that reminds you of the disorder itself. Maybe you know someone who actually had that specific disorder? You could use that person to represent the disorder in general. I do that often when I memorize laws. Some co-workers who work in a specific area of the law or have a specific job, often represent a specific law or sometimes just abstract concepts of the law. Sometimes you just have to set an image to represent something abstract because you probably don’t always have an image that comes to mind instantly (if you do: use what comes up naturally, it usually works best).
Then in the first room I’d put images that represent the information from A. It’s quite hard in the beginning but with training you’ll get better at coming up with images for abstract information.
For example (A.): A depressed person sits in the first room, on the wall you see a calendar where more days than not contain a that the depressed person has drawn there himself/herself. On the other side of the room you see someone else with binoculars and their own calendar also drawing . You could see two seasons passing (like leafs falling or snow for example) to remember that it must be for at least 2 years. Or you could imagine your image for the number 2 (for me that would be a swan) who is affected by the seasons changing.
Some things that come up often in diagnostic criteria (for example: “at least” or “more days than not” etc.) could also be turned into images that will always be the same. This way you will already have images prepared for the things that come up often, this will make it much easier in the long run since you build up like a “visual vocabulary”. For example: “contract” for me will always be two people shaking hands. In constitutional rights it’s often “freedom of …” so I use an image of the statue of liberty + the image that represents the rest (like “freedom of coalition” = a koala hanging on a statue of liberty).
You should try to come up with images that make sense to you. They don’t necessarily have to make sense to anyone else, since everyone thinks/memorizes a bit differently.
I never really memorize anything word by word, but you could search the forum for discussions on verbatim memorization, there might be useful tips for that.
I hope my examples make sense to you You can always ask if you have any more questions.