MidWestMom, New Zealand's health care system is very similar to Australia's. In fact, our countries are so close in so many ways that when we visited NZ, we were covered under their health system, just as they are when they visit Australia.
Pagankat, have you had a neuropsychologist assessment done? It should be possible for you but it can be expensive. I'm not sure if your health system has mental care plans (which we have un Australia) which makes it more possible to get services such as psychologists, chiropractors etc covered under Medicare. If you have private health insurance you should be able to get some rebate back for a neuropsychologist, plus you should be able to claim anything more on your taxes.
A neuropsychologist assessment is like IQ testing plus. Schools do it too, but generally not in anywhere near enough detail. School IQ testing will give you a fairly rough idea of where the child is doing well and where not so well. When the child is fairly young, the testing is more limited. Also if the child has learning problems in any way, the testing is likely to not be accurate. However, low results in some areas and not in others can pinpoint areas of concern and show where the child could benefit from added assistance. Never accept an IQ score as set in stone; especially if you have a difficult child. Also, when the sub-scores in the IQ test (there are a lot of little tests within one larger IQ test) show large differences between scores, then the results should not be averaged out to give you one single IQ number. The low scores in such a case are usually an underestimate due to the child's learning problems. These large gaps are a signpost to the disability, but in the hands of (often school) inexperts, not only do these get missed, but higher scores in the rest of the sub-tests can mask the low scores, and this is why school testing can so often misdiagnose a gifted but learning-disabled child as "not doing so badly after all, when you consider he's not as smart as you thought."
A gifted but learning disabled child will be far more frustrated in so many ways and also needs stimulation plus remedial assistance. But being missed on both counts can lead to a lot more problems.
If your child has already been tested at school, you can get the school sub-score results sent to a neuropsychologist of your choice, for more detailed testing. That way there is no need to repeat the basic tests, but any areas of interest can be studied in more detail by the private expert. It does cost, but it is worth it because it gives a detailed snapshot of how the child is coping in a lot of ways.
If finances are an issue, see if you can get a referral to a specialist clinic at a major hospital near you. It can take a lot longer, we had to wait about 18 months which can seem a lifetime when you're desperate for answers and help for your child. But for us, even though it's 12 years after difficult child 3's first neuropsychologist assessment, it was such a good multidisciplinary assessment that it is still referred to for an accurate picture of how he presented across the range when he was 4 years old.
I don't know which of your major cities would have the services you need; my guess is, pretty much all of them could do it. But thorough assessment in a number of areas, including speech (even if his speech is normal - this needs to be formally confirmed and sometimes there can be subtle issues in the fine detail), psychology, pediatrics, occupational therapy - all have something to offer in terms of expertise in leading to a diagnosis. Whether or not to medicate is not their issue, their main aim is to assess. Medication is always your choice, in the long run.
Marg
Too funny and too familiar. 
