We did not have any issues with either of the children, when they got evaluated by the neurologist he picked up on everything just by watching the children and asking us questions. We already had an evaluation by early intervention and the PCP had decided they were both on the spectrum as well. My daughter being severe you cannot hide her issues at all so she was easy, but they picked up on my sons social issues right away and after a few simple tests found his other issues, plus at the time he was barely verbal.

I think it all depends on where you take the children and how good they are at what they do. Most professionals in the business pick up on the queues right away just as you would seeing another autistic child because you have one. I have found that if a doctor is on the fence about giving you a solid diagnosis they do not know what they are doing or are afraid to give it to you.

I wasn't impressed by the ADOS. My little one had to undergo it 3 times within a 2 month period by 3 different evaluators (developmental pediatrician, school district psychologist, and Regional Center psychologist). All 3 agreed on the diagnosis of "classic" autism. However, all 3 had different results of the ADOS despite what appeared to me to be similar behavior on the part of my DD. The developmental pediatrician said she met the criteria for both social and language impairment. The school district psychologist said she met it for language but not social. The Regional Center psychologist said she met it for social but not language. DD is more interested in social interaction than a lot of kids with ASD, so I wasn't surprised by the disagreement about whether or not she met the criteria for that domain. But she very clearly has a language delay and when the speech therapist tested her at the same time, she came out <1st percentile. So I don't know how on earth the Regional Center psychologist could claim that she wasn't language impaired.

Don't have experience with DSM-V, but I understand that makes it a bit harder to get ASD diagnosis as communication was removed one of the three core deficits which were under DSM-IV leaving social and repetitive behaviours. Our psychologist used three different methodologies including ADOS and all of the observation and testing took about 4 hours. Our son was very young as well at 26 months. We did get the ASD diagnosis despite being highly verbal given deficits in social and repetitive behaviour. We didn't really prepare for it - just need to show up and have some snacks. Expect a lot of questions but don't need to prepare. The psychologist / team will lead with any semi structured play for observation. We had done a lot of the online assessment for ASD so we were mentally prepared for the diagnosis. Two years later unfortunately the diagnosis was correct. The diagnosis just gave us a label to get help and get everyone on the same page eventually with respect to early intervention. It didn't tell us anything that we didn't know ie our child needed help.

Forgot to mention that we brought a toy that our son loved to fixate on (small helicopter) - he would take that everywhere and spin the rotor for long time. Anything small that you can help recreate what you see at home, I would bring that to the observation.

Thanks so much to everybody. I'm feeling better after reading all your very helpful answers. Will still be a ball of nerves, but I'm neurotic like that ;) I'm definitely going to bring some of the stuff he fixates on and just hope for the best.