The correct options are:
Difference with AMD is...
Different to ...
Different from...
"Difference with AMD is..." used when stating a characteristic of AMD that is unique or different from other similar objects. No real comparison is being made.
"Different to" and "Different from" are used intentionally to make comparisons, between another similar object, and "AMD". But, if you aren't comparing two things, then the second two options cannot be used. They are used only when comparing.
I had not previously been aware of seeing it printed other than as two words, but the practice seems not to be particularly new. The OED records the hyphenated noun in-between as meaning ‘(a) An interval. (b) A person who intervenes.’ The first citation is dated 1815:
He's fallen in love with Lady Naglefort, because she's an in-between.
It’s followed a year later in Jane Austen’s ‘Emma’ by:
Busy . . . talking and listening, and forming all these schemes in the
in-betweens.
As an adjective meaning ‘placed between’, it occurs first, once again hyphenated, in 1898:
White or pale-coloured silk, with an in-between layer of chiffon.
Best Answer
According to Merriam-Webster, 'in-between' is used as a noun or adjective whereas 'in between' is an adverb or preposition.
Hope this helps.