I wandered by r/ADHD and got stunned that the sub has over 1.4 million members. Even more than that was reading through the content and noting that greater than 50% of the posts were about drugs. Another significant portion was questions about getting diagnosed and symptomology, ostensibly with for purpose of obtaining those drugs at a later time. What the hell is this thing?
Looking through the posts it’s obvious that a fairly significant portion are attempting to conform their behavioral reports to fit the diagnostic criteria, however underlying that is this shotgun pattern of phenomenology. My impression is that the diversity of this population clearly doesn’t fit in a single label, the descriptions of their “attention” issues are so broad that it’s impossible for them to be governed by even remotely similar mechanics.
Looking at dementias, I feel like it’s a huge mistake at this point to segregate “Alzheimer’s Disease” and “Parkinson’s Disease” as they appear to be caused by exactly the same etiology, just affecting different parts of the brain stem. I’m still looking at “Fronto-temporal Dementia” and a few others and feel fairly certain that a similar pattern will emerge.
It reminds me that we actually differential these conditions against each other, e.g. if you have Parkinson’s you can’t have AD. Considering none of these conditions have a consistent etiological or pathological description (not technically right, most are defining AD by Ass plaques but it’s probably wrong), how harmful are these differentials when there is overlap?
The big fix for the DSM-IV’s validity issues was removing the differential between “ADHD” and “Autism”, and allowing the language to be much more relaxed regarding “co-morbidity”. What would a similar categorical shuffle for “dementia” definitions look like? Would it improve research focus or would we still be in the heterogeneous mess that “ADHD” and “Autism” are stuck in?
Thinking about this further, I think it might be appropriate to lump “Autism Spectrum” and “Schizophrenia Spectrum” conditions together as the evidence seems to suggest that these might be the same conditions at different ends of the model. My gut instinct is that “Autism” is an extremely dorsal presentation of some aspect of the hippocampal stream and “Schizophrenia” is an extremely ventral aspect. The stream imbalance is probably a downstream artifact of processing elsewhere however, rather than initiated in the hippocampus. Think of the hippocampus as plastically reflecting stream processing elsewhere.