discontent

(Online therapy is dangerous, critics say. Quacks could set up shop and scam customers. Discontents who are looking for a quick fix could score drugs with a simple mouseclick. The entire mental health industry may degenerate into a mess.)

Dose "discontent" here mean "patients"? But I haven't found this meaning in any English dictionary.

To a certain extent, 'discontents' does mean patients.

The dictionary definition of 'discontent' only gives you part of the answer.

Discontents: people who are discontent.

I would translate it as "People who are not content with conventional treatments"