Sorry this is a bit long, but hopefully it will be useful to you.
The main thing with autism is in the areas of social interaction and communication skills. Both children and adults with autism typically show difficulties in verbal and non-verbal communication, social interactions, and leisure or play activities. Autism affects each person on an individual basis, so the symptoms are unique to each individual, they can be in any combination and range anywhere from mild to severe. You can have 2 people with the excat same characteristics and they will act completely different from each other. There are also different forms of autism.... autistic disorder (aka classic autism), asperger's disorder (some refer to it as high functioning autism), and pdd-nos (pervasive developmental disorder-not otherwise specified aka atypical autism). Each has it's own criteria for a diagnosis and each form can also range anywhere from mild to severe . This will tell you about what criteria has to met to be diagnosed with the forms of autism: http://www.autism-society.org/site/PageServer?pagename=about_whatis_PDD There are also related conditions of autism, which can have similiar symptoms and/or share some symptoms of autism or can co-exist with autism: http://www.autism-society.org/site/PageServer?pagename=about_whatis_related When someone is evaluated for autism, various medical tests may be ordered to rule out or identify other possible causes of the symptoms because many of the behaviors associated with autism are shared by other disorders. To be diagnosed with autism, they would need to be evaluated by a psychologist; developmental pediatrician; pyschiatrist; or a neurologist. The evaluation they use would depend on who they see. An accurate diagnosis should be based on observation of the individual's communication, behavior, and developmental levels. You may find he has a form of autism or a related disorder order of autism or something entirely different, you won't really know unless he's evaluated, even if you have any doubts it's better to know for sure than to wonder or to find out at a later time he does.
You're basic symptoms are: http://www.autism-society.org/site/PageServer?pagename=about_whatis_char
Insistence on sameness; resistance to change
Difficulty in expressing needs, using gestures or pointing instead of words
Repeating words or phrases in place of normal, responsive language (echolalia)
Laughing (and/or crying) for no apparent reason showing distress for reasons not apparent to others
Preference to being alone; aloof manner
Tantrums
Difficulty in mixing with others
Not wanting to cuddle or be cuddled
Little or no eye contact
Unresponsive to normal teaching methods
Sustained odd play
Spinning objects
Obsessive attachment to objects
Apparent over-sensitivity or under-sensitivity to pain which ties into Sensory Integration- any of their senses can be over or under sensitive
No real fears of danger
Noticeable physical over-activity or extreme under-activity
Uneven gross/fine motor skills
Non responsive to verbal cues; acts as if deaf, although hearing tests in normal range
Aggressive and/or self-injurious behavior
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If you are in the US, you can request from his school an evaluation for learning disabilities. Do everything in written form or email so you have copies rather than doing it orally. They will require you to sign a consent form for the evaluation, once they receive the consent, then they have up to 60 days to perform the evaluation. A school cannot make a medical diagnosis of a specific form of autism (autistic disorder aka classic autism, asperger's disorder, pdd-nos -pervasive devlopmental disorder not otherwise specified aka atypical autism), their diagnosis would be autism spectrum disorder instead of a specific form e.g. my son had a diagnosis of autistic disorder from a psychologist outside of school in which I provided documentation of the evaluation and diagnosis of, when he was evaluated from the school he was diagnosed with autism spectrum disorder rather then the specific form he does have. An evaluation from the school should consist of a speech and occupational therapist and a psychologist. They must take into consideration anything you provide to them whether in written or oral form in regards to his disability (ies) such as the results of his speech and occupational assements that have been done. Depending on the results of the evaluation and any other conditions he may have will depend on the services he receives. If they find he meets the requirements set forth by IDEA (individual with disabilities education act), then he would receive an IEP (individualized education program), which outlines exactly how he is to be taught. Once the results are discussed with the parents and if he is found to be eligible for an IEP then they have 30 days to have a IEP team meeting and set up his IEP, but the meeting to discuss the results can also include the IEP team to set up an IEP for him as well. During the meeting to discuss the results they must provide you a copy of the evaluations and the results of them, including what types of tests they used and their purpose. An IEP will state short & long term goals, any modifications, accommodations, supplements and related services (speech/occupational therapies, counseling, transportation, and more) he may need. If he does not meet the requirements set forth by IDEA, then he may receive a 504 plan, which allows him to receive some help, but not all that is available under IDEA.....Section 504 of the Rehabilitation Act of 1973 requires public schools to provide accommodations to students with disabilities even if they do not qualify for special education services under IDEA. The definition of a disability under Section 504 is much broader than the definition under IDEA. All IDEA students are also covered by Section 504, but not all Section 504 students are eligible for services under IDEA. Regardless, the parents will be either a part of the IEP team or the 504 planning committee.
If he does receive special ed services under IDEA, that does not necessarily mean he'll be in a special ed class, they have what is called least restrictive enviroment (LRE), which basically states that to the fullest extent possible children with disabilities must be educated with children who do not have disabilities. Depending on his needs will determine which educational setting is best for him. You do have the right to request an Independent Education Evaluation (IEE) from the school if you do not agree with their evaluation and you can request that the school pay for this.
Even if you have him evaluated through the school, I would still have him evaluated outside of the school, the evaluation outside of the school will be much more detailed than just testing him for the educational aspect of it e.g.it took 1 month for my son to be evaluated outside of the school, the school only took 2 hrs to evaluate him, it will also allow him to receive any services he may need related to autism/other disorder(s) outside of a school setting besides the speech and occupational therapy he is currently receiving.
This link is to IDEA, this page will tell you about evaluations, eligibility determinations, IEPs, & educational placements.
http://idea.ed.gov/explore/view/p/%2Croot%2Cstatute%2CI%2CB%2C614%2C
This link is to the US Dept. Of Ed. IEP Guide, it will tell you everything about an IEP starting from the evaluation to the team members and their roles, to the IEP content, a list of services he can receive, and more. http://www.ed.gov/parents/needs/speced/iepguide/index.html
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Personally I would not recommend anything by Jenny McCarthy, she is a joke.
I blame her along with DAN doctors for making people believe there is a cure for autism, to me that is a sense of false hope. She states she uses a variety of biomedical treatments for son (what DAN doctors use), one of which is the GFCF diet (gluten free casein free). She states that her son has recovered/been cured from autism, but yet she states that if anything in any of the biomedical treatments are changed such as having a food that is not acceptable in the gfcf diet, not giving a supplement, etc., he becomes worse, why does he become worse..because the autism is still there. I don't get it, if her son is in fact recovered, cured, or his autism has become reversed, however she'd like to put it (she's used them all), why would she continue to treat him for something he no longer haves, it makes no sense. That would be like me having a cold, taking medicine for it, the cold goes away but yet I still continue to take medicine for it even though I no longer have it ..I know that there's a major difference between having a cold and having autism, but wanted to make a point. Autism affects each person on an individual basis, each treatment has to be done on a trial basis, what may work for one, may not necessarily work for the other or you may not see the same results. These biomedical treatments are simply a way to help manage/control the behaviors associated with autism in some, they are not by any means a cure. If in fact she stopped any of the biomedical treatments, the behaviors associated with his autism would again become more profound and harder to manage/control. I see it all the time on here how people claim they have reversed/cured/recovered the autism in their child/children, but yet everyone of them are still treating their child/children with biomedical treatments, again why would they continue to treat them for autism if they no longer have it. Please don't take me wrong, these treatments do help some, not all, but they most certainly do not cure, reverse or make them recover from autism.