Who came up with the diagnostic word “disorder”?

I just can’t wrap my mind around this: Using the word “disorder” to tell people that they have a mental illness that is
nothing to be ashamed of, it’s just like diabetes or any other physical
illness.

How can any
amount of anti-stigma campaigns neutralize the wrongness that this word
conveys?

Merriam-Webster defines it like
this:

: a confused or messy state
: a lack of order or organization

: a state or situation in
which there is a lot of noise, crime, violent behavior, etc.

medical : a physical or
mental condition that is not normal or healthy

Full Definition of
DISORDER

1 :  lack of order

2 :  breach of the peace or public order

3 :  an abnormal physical or mental condition

 

Examples of DISORDER

The mayor is concerned
that a rally could create public disorder.

problems of crime and
social disorder

Millions of people suffer
from some form of personality disorder.

 Related to DISORDER 

Synonyms

chance-medley, confusion,
disarrangement, disarray, dishevelment, chaos, disorderedness, disorderliness,
disorganization, free-for-all, havoc, heck, hell, jumble, mare’s nest, mess,
messiness, misorder, muddle, muss, shambles, snake pit, tumble, welter

Antonyms

order, orderliness

Related Words

anarchy, lawlessness,
misrule, riot; knot, snarl, tangle; labyrinth, maze, web; maelstrom, storm;
bollix, clutter, litter, mishmash, shuffle; hodgepodge, medley, miscellany,
morass, motley

Near Antonyms

method, pattern, plan,
system