I think it can be hard to know what you're born with vs. what developed in your brain between ages 0-2 let's say. It's just a theory so we don't have to really lean into it much, but to me it I could definitely see that trauma in such early years may make really strong changes in the brain.
It’s really not hard to trace genetics, however. If one is ONLY studying trauma victims? Then it might be hard to know what runs in families; IE by way of hereditary, vs by way of experience, vs both (dormant genes activated under certain conditions, only). The whole nature/nurture/both, thing. But 4-6% of the population has ADHD. The general population. There are
not clusters of higher rates of ADHD amongst trauma, climate, ethnicity, diet, region, religion, parenting styles, etc. etc. etc. Which were all theories back in the 70s & 80s, and so thoroughly disproven, (and heredity proven), that it was reclassified.
Argued for in the DSMIV (THAT long ago!) & finally changed in the DSM5. Partly that was politics, as other key features were also argued (that it’s not a childhood disorder, which it isn’t; that all 3 types have a hyperactive component -physical, mental, & combined type); as well as a host of minor tweaks. But there wasn’t enough data to make such profound changes all at the same time (in no small part because it had become a “pop-illness” in the 80s, so data was diluted) and because genetics research was absolutely exploding at the time. So it was (to oversimplify) “Get some distance from the 80s BS that diluted understanding; some rock solid longitudinal evidence from socialized med countries that will be looking at a over a century/6+ generations by the time of the next edition; and FFS use the new toys (genetics & genome) to add as much hard science as possible.
Hereditary proven =
1. the only population clusters? Bloodlines/Families, occupations/careers, & “recreational” stimulant use/abuse.
2. It’s in our coding DNA, rather than our non-coding /junk DNA (which requires activation). I haven’t looked up, recently, to see if we know the exact gene sequences, but even 20 years ago we knew roughly where it lived in the genome.
Is there a lot of crossover between Spectrum, ADHD, & PTSD? Yep! There’s sooooome crossover with ALL disorders & conditions, as all disorders share symptoms… but some disorders share more than others. (Just look at what a disorder’s most commonly misdiagnosis are to find its nearest. Like PTSD is commonly misdiagnosed as bipolar disorder, or anxiety & depression.) ADHD & Bipolar Disorder actually share soooooo many symptoms, far far more than PTSD & Bipolar share, that they’re considered “sister-disorders” & often the only way to determine which is which? Is a medication trial. (That also tells you they’re not the same disorder on a spectrum).
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Just to touch on a few shared symptoms between Autism Spectrum, ADHD, & PTSD?
1. The constant flood/influx of information that neurotypical people not only filter out unconsciously, but can do deliberately to an even greater degree
- Autism Spectrum is the most severe (of these 3); on all the time, with no way to filter or organise, nor learn to filter nor organise; only life long coping strategies (or certain oblivion/sensory depriving-drugs) have any effect.
- ADHD is on all the time, but whilst unfiltered, ADHD brains appear to learn to organise it unconsciously, and coping strategies will be necessary 24/7/365 for the duration of their natural lives. Sensory depriving drugs are often used in conjunction, but are (most often) specific to the disorder, as the same drugs that reduce sensory input in ADHD brains, increase it in neurotypical brains.
- PTSD only experiences it in brief episodes of hypervigilance that, like all PTSD symptoms can be completely eliminated.
^^^ Only Spectrum & ADHD (out of these 3) include MASSIVE dysreg as a natural consequence/effect (Autistic & ADHD sensory meltdowns) that can be mistaken for PTSD/Trauma trigger meltdowns/episodes/psychosis, or bipolar “mixed episode” (ripping the clothes off of your body, screaming, hitting/kicking/biting, throwing furniture, breaking everything within sight, smashing yourself into walls/floors, self harm, & suicide). By adulthood most HFA (high functioning autism) & ADHD peeps have learned to a) manage their sensory exposure / windows of tolerance / emotional monitoring & regulation to limit the number & severity of these meltdowns, & b) how to get somewhere private, so even the lesser versions of them are not inflicted on others (both animate & inanimate).
There are many many many other disorders that share “too much information” &/or “sensory processing” issues. Some notable ones? Schizophrenia & schizoaffective disorders, SPD (sensory processing disorder), GAD (general anxiety disorder), OCD (obsessive compulsive disorder), & certain types of eating disorders.
2. Okay this got long, so I’m not going to compare & contrast symptom sets anymore right nooooooow but they CAN be done, for every single shared symptom, of every disorder.