Neah - let us say that 9 out of 12 is significant. If you had 2 out of 3 say for coronary artery disease or diabetes, you'd have a diagnosis.
Whilst I agree it is significant and local help should be sought ASAP, I disagree to try and compare mental health to physical health. Physical health is measurable, can be screened, recorded, imaged, and confirmed. Mental health... not so easy.
You can have every symptom of PTSD and not have PTSD, all because the severity is mild in each symptom and does not meet that last criterion, where
"the disturbance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning."
You could have the bare minimum of symptoms, yet each is severe and causing clinically significant distress. You get the idea...
I've had some long conversations with psychiatrists about this over the years, and at the end of the day most concluded something to the likes of, it all comes down to good medical diagnostic capabilities in their view with best guess based on experience.
It's not uncommon a person with PTSD will lie on their assessment forms, dismissing near most important aspects and downgrading the severity of their lifestyle. Well, it is a majority with PTSD who will downgrade their severity. To an untrained specialist, they would conclude the person doesn't have PTSD. Then you have those who want to have it, so they tick all the severe / close to severe answers, say the right words, and they get a PTSD diagnosis when it's likely they don't have PTSD at all.
Thinking about it, near every shrink I have spoken with or has taught me about aspects of PTSD over the years, seem to elude towards those who try to imply they have PTSD usually do not. Those who dismiss their severity, the shrink is usually making phone calls to spouses or family members to get them into their office for a true picture of the person, if they can't completely tell just by looking at their demeanour.
It was like talking with my local GP the other week... he see's it daily with all these web doctors walking in his door telling him what is wrong with them. The majority tend to leave disappointed and upset... apparently it is quite normal they then doctor hop until they get enough actual medical information to present with the correct words and symptoms to display. I know the medical terms, hypochondriac. Apparently the web makes their job interesting...