The purpose of this study is to assess the safety, tolerability and effects on behaviour of Syntocinon given intranasally (by a spray into the nostrils) compared to placebo (an inactive saline substance that contains no medication) in participants with frontotemporal dementia/Pick's disease. This study will take place in approximately 15 centres across Canada and the United States. Approximately 112 patients in total will be enrolled in this study. In the first phase we will examine which of three different dosing schedules of oxytocin may be more effective. In the second phase of the study, patients entering the study will be randomized to the oxytocin dosing schedule that appeared most effective in the first phase.