There is an R word in the special needs community that people rarely say and it is not the one you are thinking of. It is regression.
Regression is a contrary brat. You teach your child the skills they need to hold a conversation, play in the sandbox with others, make friends, get through an entire tightly scheduled school day, and to plan their homework. They learn these things and you have a great year. A great six months, a great super long span of time and you think this special needs parenting thing is not so bad. You got it.
Then one day you realize one or more of those things are not happening now the way they used to, that children are being bullied by your child and homework never makes it home and your child is throwing fits at you as if he were three and yesterday he pinched his sister.
This is the fault of regression. Your child no longer has the skill or skills he once had, and you have to go back to square one and start over on teaching him.
Then in your spare moments you rack your brain trying to figure out if your son had a recent trauma that would cause such behaviour. You date his last fever and you call the school and the daycare providers and ask if his regression dates from within two weeks of that day. Because that could be mitochondrial issues, necessitating very invasive testing. You think about seizures and diet and f*@#ing everything, desperate not to get the skills back, which you know is a lost cause, but just to get your kid back on some sort of level playing field so he can be ready to learn all over again.
On the phone with the school they describe the behaviours you have not seen in about two years and you die inside. The school thinks he is being difficult. You explain this is a medical issue, he is AUTISTIC. They insist he learn to love the drag on a pencil and you explain he has sensory issues, that in fact he has SENSORY PROCESSING DISORDER which you have explained until you are blue to everyone at two schools and finally someone says they will let him use marker. So the pencils and the crayons don´t hurt his brain anymore. He can use marker after his one sentence in pencil and you thank the gods for small favors.
But really your kid is just autistic. There are a hundred comorbid disorders that could be diagnosed later in life, but that brat regression is not going to finger anything specific for you. You have to find a pattern. You need the right mind reading supernaturally insightful doctor. You find a story that matches yours so exactly that you start asking questions based on the diagnosis of the kid in that story. One question to the right medical professional might pan out. You fumble around, lost, trying to help your child learn to survive in an unsympathetic world and you just pray that somebody, somewhere, understands that he is not ¨being difficult¨. He is REGRESSING. It is not part of his learning process. It is his neurology.
You start the education back at square one, you alert the medical team and you wait. Because you are helpless. Because regression is not a fight. You just lose. You lose.