It is likely that multi-factorial aldehyde "insults" or contributions are at work in any one case of onset of dopamine deficiency and its rate of progression. Each person will have a different combination of contributions to the aldehyde overwhelm which result in the dopamine deficiency, and everyone will have a different "final straw that broke the camels back". This is why so many difference potential "causes" of PD have been identified in the scientific literature, but why no single universal cause has been found true for everyone. It is also why there is no one universal supplement, drug, diet or therapy which is beneficial for all people with PD, and why every one of us has a very different response to these.