There's no worry honey.! I have a five year old autistic son who is very high functioning he's borderline gifted. But he didnt talk until three years old. Not only didn't he speak he was and still can't understand or follow directions even with pointing gestures. I also have a 18 month old son who is normal and does all the things same as your son. He understands but rarely says words although he was saying a few he now rather points grunts and gestures. But if he's able to understand that level of simple comprehension is a good thing. In my autistic son it took years to reach this level.
We do not know what causes autism or developmental delays. Cutting out dairy only helps if the person has an aversion/allergy to it. Same with gluten or any other allergen. Getting rid of dairy may help one person with autism, but it may not help another. That's the thing with autism, it shows differently in each person. Different treatments help different people. It is very misleading to say that eliminating dairy products will help your child regain their speech. It might not. Same with a gluten free diet. Worth a try, but no guaranteed results. A treatment plan needs to be constructed with a developmental physician that understands autism.
15 months is VERY young. there is no clinically relevant test at this age. Even for 2 years its not been validated experimentally (i.e. diagnosis holding up into older age). This is truly not a clinically significant test until age 6 though its being done at age 1 and certainly has relevance for diagnosing speech delay well before 6.
10% of boys have a speech delay of significance. I think eventually we will get to something like 5% autism because its been thus redefined. Autism diagnosis in the case of ASD not classical autism is a matter of OPINION. One doctor can say autism another can say speech delay. You have to decide what you want. I think there is a significant group of kids with sensory issues and speech and neurological delay but they usually catch up, some in 2 years some in 4, it really can take time. I know social people with poor eye contact and I think its nuts to pathologize kids as is being done and freaking parents out. But again, Im in a minority. There are autism support groups up the wazoo and a whole industry of professionals who are overpaid to remedy this. Then the kids need support when theyre older and dont have it. My advice always is to enjoy your child. If youre concerned about speech you can get free speech services from the state or privately through insurance. You can do ALOT yourself. The first step is always communicating needs. You can do this with body language or words/sounds. Place something he WANTS out of reach. Dont dangle it. Say the word or the movement you want and repeat this. It works phenomenally. Love is what make kids great not interventions. L
Speech regression is one of the first signs of possibly being on the autism spectrum. Dairy products ,especially casein, a milk protein shuts down the brain's speech center. After putting your child on a casein free and hopefully a gluten free diet , too it will take 3 to 6 months to bring back speech. There must be no cheating-- a little bit of dairy will set this time frame back. If ,once you have success, you think removal of dairy couldn't possibly be the answer , start giving your child dairy products again if you dare and you will hear the words being garbled in just 4 days and all words will disappear soon after that. Going dairy free again will take 3 or more months to regain speech. This observation is from a mother of a 35 year old male with autism who lost his speech at 18 months and later regained it. Good luck to you.
Eldermom
Definitely speak to your pediatrician about this. Regression is a sign of a developmental delay.
You're worried: speak about these symptoms with your pediatrician now, she/he will examine your child's behavior and will be able to tell you if they mean something or not. Better be on the safe side.
Good luck!