Every single person here will tell you, with good reason, NOT to attempt to hide anything when you're doing your paperwork.
The military has been at 105% R/R (Recruitment/Retention) of their required quota, so they have the luxury of being extremely picky of who they accept - with this economy, the military is just too good an option for a lot of people to cast aside.
No matter how small the lie, no matter whether it was intentional or innocent, once they find out, and they WILL find out, you're gone. Let's say you do lie and get in, do your Basic, go to BUDs, and are in Phase II of SEAL training and getting all high-speed up for your swim test. In walks your senior training officer, yanks you into his office by your arm, and gives you a bad conduct discharge for lying on your entry paperwork... all that hard work, all that dedication... all gone, and you now have a blot on your permanent civilian record that is equivalent to a violent felony.
The military is a place for those with higher standards of honor and integrity. Especially SOG! No SEAL will ever offer you peer acceptance if you're not honest.
And that's one thing most people don't understand about SEAL, Ranger, Force Recon, etc:
Even if you complete all the schooling with flying colors, you are NOT a SEAL, Ranger etc until you have done your time in the unit and the unit has offered you a slot. You will not wear the Trident if your first duty unit refuses you, regardless of your training. It's a bit different with Rangers: if you pass RIP and The Phases, you are always "Ranger QUALIFIED." But you are never "A RANGER" until you have 12 months in "The Battalions" (75 Ranger Regiment) and have been accepted by your peers. In the Navy, a SEAL is someone who has meted out the training and already has 1 year in an operational unit with command and peer approval.
So be 100% honest, regardless of what your 1 D Ten T recruiter says. Personally, I'd find another: if he's willing to lie to the service, then he's probably lying to YOU, wouldn't you agree? Signing your name to 8 years of give-your-life away should be a decision made based of fact, not a recruiter's lines of BS.
Since PDD is closely linked with Autism, you're probably going to have to have your jacket screened by the MEPS medical review board. Since you've not been on medication since your pre-teens, which the military uses as a threshold for "clinical prescription dependency," it's highly unlikely that they'll review your case background and refuse to sign off on it.
But this is where you HAVE to be extremely careful, and why I am taking such pains to make all of this loud and clear to you - once it's done, it's done. No going back.
If your recruiter forwards your MEPS packet and your enlistment jacket to the medical review board, and the medical review board denies you entry, you cannot go to another recruiter and try again. Let me repeat that: once the med review board says no, no it is forever - until you can get a civilian doctor to sign off on your condition, which none will do because then are then civilly liable if you get hurt due to this condition they told the military you "really don't have anymore..."
If you want your stuff wired tight, if you want to make sure there are no screw ups, no "uh ohs!" and nothing that can come back and bite you in the butt, you need to immediately begin considering what the Navy is going to be looking at as far as possible issues with accepting you.
With the PDD-NOS, you're a red flag for the military physical and mental standards. It doesn't necessarily bar you from serving, but you don't want some O-4 doctor who didn't get any from the wife unit last night grumbling through his tedious day and haphazardly red stamping you for something he's just not in the mood to investigate. Again, if he does, you're screwed. There's no medical appeals process during enlistment. And you're going to face a team of them, as your condition will require both a physical and a mental review and approval.
Here's what I personally suggest:
Before you even talk to a recruiter again, go to your mental AND physical doctors and, without explaining why, tell them you want a review of your past and current health status to possibly have the diagnosis cleared from your record. It'll be like a felony: it will always be there in your records, but you'll have been "excused" from it, which is a quack's way of saying that your condition is no longer pertinent to any level of your functioning. It's kind of like saying you're cured, but not really. It just means that this disease once affected you and required treatment, but no longer.
Make certain that the doc clearly annotates on your record that this condition no longer affects your physical or mental functioning and has no chance of recurring. That's an automatic military green light of approval if he words it that way. Problem solved.
Then obtain a FULL set of your NEW medical records and have 4 copies on hand: one for you, the recruiter, and both review boards (in case you're asked, you want to be prepared - the military likes people who are prepared). Highlight the area where the doc has stated that your condition is not likely to recur, that you require no medication, and that all levels of functioning are normal.
Then go see a REAL f-ing recruiter - one who is worthy of the position he or she serves. If they are telling you to lie, they are lying to you. It ain't their tush on the line, it's YOURS. YOU are the only person ho will be affected by a lie; the recruiter is not responsible, even if you explain that he told you to lie.
And, quite frankly, who wants to serve with someone who can't even be honest? I don't want anyone like that guarding my six, that's for damn sure.
Now, if you want, PM me and I'll hook you up with the Naval recruiter who told me to tell you all this. This guy is 100% the real deal, the area recruitment officer for the entire state. I didn't mention that your local recruiter told you to lie, only that you weren't sure how to proceed.
But I offer you this warning: I've known this gentleman for a good number of years, and he is the real deal. He will not BS you, but if you try and slide anything at all by him, he'll catch you and you can bet your seat you'll never serve a single day in any capacity in any branch of the United States Military. He is one of the few who wears a recruiter pin because he wants our Armed Forces to have the best - this isn't a cake job for relief for him. It's his entire purpose in life: put good guys in, keep bad guys out. He's 100% upfront and honest, and he demands the same.
If you want to start off with a good impression, tell him that a casual conversation with a local recruiter left you with the impression that they just wanted you to leave it off the paperwork since you've not undergone treatment since you were 11, but that you wanted to ensure that the military knew everything about you. That upfront honesty will immediately tell him that you're the type of person he wants to work with.
There's a 1:50 chance he can actually sign you up (you must reside within the state he is authorized to recruit in). But even if he cannot, he'll steer you straight on the skinny as far as exactly what you need to do to make sure you get in hassle free, if at all possible. Then you'll be informed and can go see a local recruiter armed with the information you need.
Oh, and don't mention that you want to be a SEAL. That's an instant red flag for him - he deals with 18-year old kids all day who want to be Chuck Norris. There's NO SUCH THING as a SEAL enlistment contract. You join the Navy with an MOS that is SEAL-suitable, preferable something in Combat Arms, and once you've passed Basic THEN you begin seeking out the avenue to BUDs. The list is incredibly long, the selection process equally as long and a thousand times as vigorous. They will pick apart your life from the time you got your first tooth. Neighbors, friends, family, teachers, doctors... anyone who has ever known you is going to get a knock on the door for an interview before you can even think about taking the physical test for BUDs. By the time you're even in the stack of thousands wanting a slot, they'll know how many times you've masturbated in your life, what side you used to part your hair on, how many aspirin it takes on average to cure your headaches, and what your first dog's name was. I kid you not, brother.
The very vast majority of BUDs plebes already have over 4 years in the military, with a spotless, proven track record. You're not going to go to Basic and then to BUDs. Technically, it CAN happen that way. But it won't, it never does, no way and no how.
If you're dead serious about this, then you had better have your gears synchronized. Because your chances of making it as a SEAL are right at about 1 in over 150,000. Everyone wants to be a SEAL. I want to be a SEAL. Who doesn't want to be the baddest mo fo on the block?
But when he asks you what your aspirations are, simply tell him that you want to serve your country in whatever capacity your country needs you in. He'll take a liking to you immediately. Then, after a few weeks of talking with him here and there, you may broach the idea that, "Well, I think we all think about SEAL training at one time or another, so just out of idle curiosity..."
He's an Operator before he's a recruiter. You'll never know it by talking to him unless you see him in his dress uniform. He's very quiet, very shy and very reserved. He will not waste his time or yours if he doesn't think you mete the mustard. And he's going to immediately brush you off if you call him with this, "I'm a SEAL wannabe" attitude.
If you're certain you know your direction, PM me and I'll get you hooked up with his email address.
Best of luck, bro - you're going to need it.