Ming from Agents of Speech explains why formal therapy isn't recommended for 18-month-olds. At that age, language is still minimal and conditions like speech delay or ADHD can't be reliably diagnosed. Clinicians look for matching, sound imitation, single words, and play skills instead.
So what does your child want from you usually is to want food, snacks to drink, some social time with you, play with some toys. So speech therapy or any type of therapy is not going to be optimal and it's not actually recommended because a lot of times when we are doing therapy we need a diagnosis and we need assessments. Assessments are typically very difficult to conduct for 18 months old child because the language profile of an 18 month old child is very minimal. Like are they able to match, are they able to imitate sounds, are they able to say one or two single words, how well do they comprehend stuff, how well do they play? There isn't much to actually assess on and if you're talking about oh is my child speech and language delay or do they have adhd, you can't really put a finger on the diagnosis because it requires a child to be at an older age in order to see what's going on.
