As a general rule, a lot of vitamins and supplements are ‘expensive pee’, but tailored formulas or protocols, based on diagnostics (that may not be mainstream and Medicare funded) that are interpreted by trained integrative or orthomolecular specialists, is not the same as reading Dr Google and going to the local chemist and buying a handful of vitamins!
Some of the specialists I recommend are able to work through a Mental Health Care Plan or Allied Health Care Plan (Dietary). These can be obtained from your GP (providing they support your request for referral under one of these plans).
What I do like to see in a specialist I refer to is a holistic approach that takes into account lifestyle factors. The more highly trained to understand the gut-brain-microbiome axis combined with some understanding of how epi-genetics is playing a role in diagnosis and tailored natural medicine, the higher on my preferred referral list.