Just to jump into diagnosis for a minute :
And Keep in mind I'm oversimplifying a tad / not covering every eventuality
- Disorders are "normal" things taken to extremes. Like everyone has bad memories, regrets, anger, shame, nightmares, anxiety, etc. But not everyone has PTSD.
- Most disorders share symptomology with other disorders. Some, so closely, that they're either sister-disorders (like ADHD & Bipolar disorder are sister disorders), or are actually spectrum disorders (autism spectrum is one of the better known ones).
- Disorders are classified by possessing a whole constellation of symptoms along with a few hands down requirements. With PTSD, that's CriterionA.
Black & White thinking is both a totally normal human personality characteristic as well as a symptom in several constellations. Aspies, BPD, Depression, and several other disorders all have it in their constellations.
When you have a disorder you'll sometimes twig to someone else also having the same disorder ... But an important thing to remember is that even if our radar goes off... It can be wrong. My ADHD radar pings all the time, and most of the time I'm correct (just like if you hear someone talking about something in PTSD-land, your radar pings). But it's very, very, very important not to self diagnose. Because there is always a whole host of other things something could be... And treating for the wrong thing is actually quite dangerous. Not in simply medication-land, but what works for someone who is neurotypical (or has disorderA) will often make things worse if you're actually dealing with disorderB. And then it also spawns a whole lot of confusion/misinformation.
_________ just a few examples______
To use ADHD (since it's the disorder I'm most familiar with).
Meds... When my son is having problems sleeping, I'll make him a triple shot of espresso. Bam. Out like a light. Why? Because ADHD has opposite-stimulant-reaction. ((But give that to a neurotypical kid and they've got insomnia, and give it to a bipolar kid and you've just triggered a manic episode.))
Misinformation... I can't count how many times someone has said their "ADHD" was cured! Simply by taking this supplement! ...Long suffering sigh... No. Your malnutrition was cured by taking a nutritional supplement.
Work smarter not harder... Neurotypical kid forgetting to do half the things asked of them? Cut back on the number of things asked of them. Slowly add more responsibility until they can prove they can do what they're first asked. ADHD kid forgetting to do half the stuff asked of them? Give them more stuff to do. Because whether you give them 2 things to do, or 20, they're working at about half mast. Give them 2, they'll get 1 done. Give them 20, they'll get about 10 done. What you want to work on with ADHD is increasing the percentage, not the total. If you never give them three, until they can do 2... You're setting them up for failure. Just like giving a neurotypical kid 3 before they can do 2 is setting them up for failure.