Most people in Belgrade arrange and pay for therapy privately. Serbia's public health system covers psychiatry as a medical specialty, but psychotherapy is not a service the national insurer pays for. The word doesn't appear in the health insurance law, and talking therapy isn't on the list of services a primary care centre can bill. What the public system reliably provides is psychiatric assessment and medication. Talking therapy sits outside it.
The public route starts at a community health centre (dom zdravlja) with your assigned doctor (izabrani lekar), who issues a referral (uput) for specialist care. You'll also need a validated health card. Without either, you can still be seen and simply pay for the consultation.
Private practice needs no referral. On It's Complicated you choose the therapist and arrange it with them directly, and since there's nothing to claim back afterwards, the rate on the profile is what you pay.
Psychologist (psiholog) is defined by a law dating from 1996: it requires a psychology degree and a professional examination. Psychotherapist (psihoterapeut) isn't a protected title. There's no law governing psychotherapy in Serbia and no professional chamber for it, so in principle anyone may use the word.
Psychotherapy training in Serbia runs through institutes accredited by European professional bodies rather than through universities, so the standards that apply are set outside the country. The Association of Psychotherapy Societies of Serbia (Savez društava psihoterapeuta Srbije) issues a national certificate and the European Certificate for Psychotherapy, both requiring several years of training, extensive personal therapy and supervised practice. Neither is a legal requirement and the association binds only its own members, but it's the clearest signal of completed training you'll find on a Belgrade profile. A psychiatrist (psihijatar) is separate again: a medical doctor, licensed by the medical chamber, and the only one of the three the law regulates fully.