We can buy melatonin over the counter here but it is a much lower dose than by prescription. Could your GP refer you to a geriatrician or gerontologist, different name but they deal with illnesses of the aged. My GP referred my husband to a geriatrician who then referred my husband to the memory clinic and reviews him every six months. Someone like that may be of some assistance. You don't really need a psychiatrist to prescribe a sleep medication. I can understand that a doctor may be reluctant to prescribe sleeping medication for a person with dementia. There are other medications other than Zoplicone that could be worth a try.