I have friends that went through the phase of thinking they had ADHD. Nope. Just sleep deprivation and mental exhaustion. Something incredibly common these days which massively impacts focus, mood, concentration, motivation, frustration, etc. Getting back into physical exercise and correcting sleeping patterns was all they needed to return to how they remembered themselves.

I think adults between 25–45 are especially prone to this. Everyone else is making jokes about having shit sleep and just grinding through, it becomes normalised and people forget that each mind and body has an optimal min/max sleep period—we all differ.