Genetics can make you predisposed to it, from my understanding.
The whole "nature vs. nurture" argument applies, as it does with most things in a clinical sense when it comes to psychology.
Somebody isn't born a schizophrenic (this applies to ADHD, so bear with me here), but they are predisposed to it if they have the right genetics. Typically the genes are passed from immediate family. So, say somebody with the right genetic makeup smokes marijuana, they are incredibly likely - if not inevitably - to experience psychosis. Sometimes, however, trauma can also set off psychosis. Personally, I was born with the right genetic makeup for psychotic disorders, and I eventually did develop it, and it became a full, diagnosable disorder. This was from trauma plus my inheriting my father's genetic makeup. He also developed psychosis from drugs, because somehow he had the right gene makeup for it, too.
But I digress.
When it comes to ADHD, Gen Alpha and Gen Z are more likely to develop it because we were raised on the internet and with smartphones (well, the majority of us). If they have the right genetic makeup, they are more likely to develop ADHD if they spend time online (such as TikTok) due to the rapidly-changing internet landscape.
Nature and nurture both play a role. Although, sometimes it throws a wrench in the whole nature and nurture aspect and you can literally just develop it willynilly if you have the right genes. That's the nature part.
The nurture part can also apply, but it's less common. Take the teenagers who saw those tick girls on TikTok and then they suddenly developed ticks. It's a social contagion and I'd argue it could be a mass psychosis. That's why there's so many cases of ADHD/autism in the younger generations - it's a social contagion because of the internet leading them to believe they have these disorders, so they actually do develop the symptoms of said disorders.
The brain is a very, very funny thing. While these "nurture disorders" are not real, so to speak, they present themselves as real.
It's all too complicated even for me to understand (someone who has studied clinical psychology for the better part of a decade + has diagnosed ADHD, schizoaffective, and complex PTSD), but I'm still trying to understand it.
TikTok is a social plague on society, and the sooner it's gone, the better and more my generation and the upcoming generations can be "normal"/neurotypical.
