Is there any practical difference between the various assessment methods?

I had a relaxed assessment, broken down in sections over 4 appointments with a private clinical  psychologist. I provided pages and pages of situations and things I find difficult etc, and a complete breakdown of all the key areas for diagnosis, for each life stage lol. My adult children, mother, sister and ex all provided a little write up about how I am/was growing up. 
I had to fill in a sensory questionnaire, and the AQ50 twice, and something else that I don’t recall. I also had a complete cognitive assessment lasting several hours to assess my strengths and weaknesses. Lots of questions, memory tests, visual processing, verbal reasoning, all sorts. I was observed, and I had a a lengthy one to one in depth interview etc.

The report included some advice and suggestions, and we covered a few of these topics during the interview. There was support available, but I wasn’t in a position to pay, having just paid for this assessment, and my daughters. 

Some private assessments are the same as the NHS ADOS, which is too rigid and quite frankly, childish. The questions asked are standard, and if you present more like a masking female, you aren’t likely to get a diagnosis. But this also depends on the budget available in your town…..My teenage daughter had that first, and we were both shocked at the level of it, considering it was ‘the advanced one for adults’…..

Aside from diagnosis, the lack of post-diagnostic adult support and assessment (where it really should be a “one stop shop” rather than people having to research/search for support themselves, without thier even knowing what kind of support they even want or need) from either the NHS, Councils or autism charities, is incredibly frustrating - of those private autism charities that do not (exclusively) cater to children’s autism, these are incredibly expensive and still require a GP referral, which post-Covid, is very difficult to even get an appointment with a GP, even if on the phone or online - in one sense, I get why children with autism are the priority, but where does this leave us adults with this condition, where in many cases, we are diagnosed later in life and neither is there support for friends/family/employers, etc, to help them better understand and/or help us to manage our condition/disability - there are so many parallels here with the struggles for LGBT rights and equality, which as an older Irish gay man living 21 years in the U.K.,, I’m only too familiar with 

I would disagree. If something is not necessary, merely a recommendation, it remains not necessary. It does not become 'quasi-necessary'.

The main problem is that the team-based approach is proving unworkable, leading to waiting times for autism assessment of over two years in some areas. Whereas the intensive, multi-clinician team approach is probably necessary for the diagnosis of young children, for adults who are fully capable of describing their traits and experiences, it is a ridiculous level of overkill. This is particularly so because being a diagnosed adult usually leads to no meaningful support. Clinicians doing autism assessments of adults are not gatekeeping an El Dorado of financial benefits.

CG 142 guidance dated June 21 paragraph 1.2.5 actually says a comprehensive assessment SHOULD be team based and draw on a range of professional skills.

The important word here is 'should' and its legal definition which is an advisory term and not a mandatory term like 'will' and 'shall'.

its is very easy to see why some clinics particularly private ones will interpret this as mandatory. As they avoid any potential issues at a later date if someone appeal a diagnosis result. 

I am not sure i would say its factually wrong either as it probably how their lawyers haver interpreted the guidance to avoid future liability

I was diagnosed by a consultant psychiatrist. The psychiatric approach for adult autism diagnosis seems to place more emphasis on the patient's own history, with tests and direct observation taking a less prominent role. Which suited me, because my masking is pretty flawless; only when I'm exhausted or very, very anxious would my autistic traits be at all noticeable. 

Martin,

thanks for the explanation makes quite a bit more sense to me now. My assessment was via private medical insurance through work so i didn't have a choice in who i went to.

ADOS is a horrible and stressful assessment method to go through and i know a lot of people write this off as childish, on the plus side of the feedback was extremely positive in identifying communication and sensory issues and a big help towards unmasking.

Grogu's Dad said:

On my assessment report it says that to get a successful clinical Autism diagnosis you must meet the criteria of both ADI and ADOS and the assessment must be carried out by a multi discipline assessment team with all disciplines being in agreement.

Well, this is factually wrong. That is just some clinicians thinking that their approach is the best, but extending that idea - wrongly - to become "All other approaches are invalid".

Taken verbatim from the NICE guidelines for the assessment of ASD, "Diagnostic assessment, which in the UK uses ICD-10, is often within a multi-disciplinary team but at a minimum is by a qualified clinician, usually a clinical psychologist, psychiatrist or neurologist." From the document: Autism Recognition, referral, diagnosis and management of adults on the autism spectrum, National Clinical Guideline Number 142, p. 25.

I think there is a welter of problems regarding diagnosis and support. The NHS seem to have chosen the most long-winded and expensive method of making adult autism diagnosis. Firstly, it seems to be based on that used for children, with very little modification for application to adults. Secondly, it involves a team of clinicians and takes a long time, therefore it is expensive and allows ridiculous backlogs to build up. This has been recognised by the NHS increasingly paying for private assessments that are quicker and often employ only one, suitably qualified, clinician (the 'Right to Choose' scheme).

Many employers, local governments, social services and educational institutions etc. have no idea what constitutes a valid autism diagnosis and entirely wrongly deny people support that they are fully entitled to. Very often some incompetent pen-pusher makes up erroneous rules, unfortunately, they are not often challenged, as they ought to be.

Grogu's Dad said:

i get the feeling it can be a bit of a lottery how the assessment and follow up support process plays out

It certainly seems to be with the NHS. They are mostly well meaning but under resourced and seriously overworked so the quality of the service is variable at best.

If you can afford it I would recommend going private and get a therapist who has experience of working with autists.

To discuss the different methods of assessment in depth you probably need to speak to a psychologist of psychiatist who specialises in that field, but that will cost quite a bit I suspect.