Can ADHD be evident at 18 months old?

[SinkGirl]

My twins are 2 this weekend. One had a lot of health issues from birth, which were improving and he was doing well developmentally when he started walking at 17 months... then he had a big skills regression, stopped doing many things he had learnt, stopped playing with toys or mimicking, regressed vocally etc.

Since then he’s been diagnosed with a vision disorder and an MRI has shown brain damage from the neonatal period but they say it’s probably not related to the regression. He’s now being assessed by various teams, just started portage, waiting for SALT, having blood tests for various genetic and metabolic disorders.

ASD has been mentioned multiple times as a possibility but I’m not sure it fits. Yes, he has had a skills regression and struggles with communication (no pointing, no words but his twin is the same) but there are no meltdowns, no difficulties with eye contact, nothing related to emotions that I can see. The biggest issues are that he seems completely unable to focus on anything, and is constantly active - running, jumping, spinning etc. Also sensory seeking (mainly constant mouthing of objects).

Could it be ADHD at this stage or is it too early? I’m just trying to familiarise myself with the possibilities so I can help him as much as possible

I don't know whether they can diagnose it, however both mouthing and acting like the Duracell bunny are both totally normal at 18 months. In fact probably less normal not doing either.

Thanks :)

His twin mouths stuff too - he’ll pick something up, quick lick or chew, then plays with it. But the other only picks things up to chew them, is chewing on something or other from the time he gets up to the time he goes to bed, literally constantly. His only interest in objects is chewing them (and if they disintegrate, consuming them). His brother is a crazy climber who loves a good run around, but this one constantly is moving in some way or other at all times.

It’s so hard not to compare. I know the doctors are concerned with the delays (they’ve assessed him to be half his age or less in all areas except physical) so will see what happens.

My brother was diagnosed with ADHD back in the 90s but he was older and I know understanding of it has progressed since then. My mum died before I had the twins so I can’t ask her about it.