Like a lot of C&P examiners, he doesn't realize what he's doing when he checks off various boxes on the DBQ. But in this case, his ignorance is probably to your advantage.
This is the exact description from the General Rating Formula for Mental Disorders (the link Carlie posted) for a 10% rating:
[X] Occupational and social impairment due to mild or transient symptoms which decrease work efficiency and ability to perform occupational tasks only during periods of significant stress, or; symptoms controlled by medication.
However, he endorsed the following symptoms/problems, which correspond with the various rating levels as indicated:
[X] Depressed mood [30%]
[X]Anxiety [30%]
[X]Suspiciousness [30%]
[X]Panic Attacks that occur weekly or less often [30%]
[X]Chronic sleep impairment [30%]
[X]Disturbances of motivation and mood [50%]
[X]Difficulty in establishing and maintaining effective work and social relationships [50%]
[X]Difficulty in adapting to stressful circumstances, including work or a work like setting [70%]
[X]Inability to establish and maintain effective relationships [70%]
There are three general scenarios:
1) Mean-spirited or lazy Rater - "The doc checked off the 10% description, so vet gets 10% rating."
2) Perhaps overly generous, less thorough, or "vets have been screwed, so I'm going to give 'em as much as I can" Rater - "Doc checked off two of the 70% items on the Symptom List, therefore vet gets 70% rating."
3) Conscientious, hard-working, caring Rater - Reviews all the relevant evidence, especially progress notes from your treating psychiatrist and/or psychologist (or clinical social worker), statements you and any family members or friends submitted, and your military personnel records. He or she will start with 70% and look for evidence to support that rating, since the C&P examiner did endorse two of the 70% items from the Rating Formula. If the Rater finds information that supports those two items, e.g., frequent, fairly serious problems at work due to PTSD symptoms, strained marriage (or no spouse or partner), no friends, alienates others, etc., then he/she assigns a 70% rating. If the Rater doesn't find evidence (or not enough evidence) for those two items, but he or she does find evidence for other 70% items (see the Rating Formula that Carlie posted for the list), then they rate at 70%. If the only 'evidence' for 70% is the two check boxes the (uninformed) C&P psychologist checked off, then they move down to 50% and look for evidence supporting that rating level. And so on.
In your specific case, from the examiner's report, and especially if your treatment notes are consistent with what the C&P doc wrote, it looks like there is evidence for "Inability to establish and maintain effective relationships", but there is not evidence for "Difficulty in adapting to stressful circumstances, including work or a work like setting" (since you are working and he didn't say anything about major problems on the job). Obviously that would change if your treatment notes or other documentation shows you have been having major problems on the job.
The fact that you haven't been in treatment for the last year is a concern for two reasons:
a) You are suffering from a very painful and disabling mental disorder. Free help is available. Why aren't you getting it? You served honorably, risked your life to protect the rest of us, and you are hurting--get the help and support you deserve!
b) Some Raters will reasonably ask, "If it's so bad, why isn't he getting help?" Now, they can't officially use that against you, but you have to admit it's a reasonable question for them to ask, and it can influence their decision.
But, having said all that, I'd put good money on 50%.
And I'm going to say it again: Get back in treatment. If you didn't like the VAMC, go to a Vet Center. If you didn't like the psychiatrist, ask for another one. If they put you in group therapy when you're uncomfortable with groups of people (duh, it's a major problem with PTSD, I don't know why the VA pushes group therapy so much), insist (politely) on seeing an individual therapist. If they say there's a 6 month waiting list for individual therapy, ask for a referral via the Non-VA Care office to a PTSD specialist in private practice that the VA will pay for (that was part of the new law Congress passed and the President signed into law in the wake of the phony wait list scandal). If they give you the run around, call your Senators and Congressman, your VSO, and your local news stations. If there's one thing VA administrators don't like, it's bad publicity. So if they f--k with you, give 'em hell.
Hopefully you won't need to do that since it sounds like you received decent treatment back when you were going, and, despite all the bad press recently, most VA docs and therapists genuinely care and try to do a good job.
Good luck man. I honor and respect you for your service to our country.
Henry