What do you call someone who has a disease or mental condition?

Solution 1:

The phrase person with x or person dealing with x is often used. The terms patient, victim, sufferer and the like all have a significantly negative and helpless connotation that many of us reject. Even survivor is tinged with victimhood that many reject.

We are not defined by our diseases, but are people who happen to be living with (and managing) them.

Solution 2:

I would go with afflicted.

As a verb, to distress with mental or bodily pain; trouble greatly or grievously.

• to be afflicted with arthritis

As a noun, person or persons in constant suffering of body or mind.

• the afflicted often suffer in silence

Solution 3:

You could try: "Those/People diagnosed with 'x'..."