I understand you may have found a lot of help for yourself from stimulants, but please do understand that they are not do all solution for everyone.
I didn't say that it was a solution for everyone. Probably I didn't speak English, so my mistake.
What I understood is that he had a diagnosis of ADHD and needed a stimulant but there were issues about anti-doping.
What you say is that he didn't have yet a diagnosis and no recent evaluation (less than a year) has been done. So I apologize for the misunderstanding.
I said that if your son can benefit of it, then, it worthes the effort to manage this situation with the team's doctor and with the federation. But first, you have to get a proper diagnosis and a complete evaluation. The complete evaluation will help if your son were in need for an authorization to take a stimulant before competing.
If the psychiatrist thinks that he can benefit from a stimulant, then he can provide the whole documentation about it, like evaluations and so on. Then, after that you get the whole evaluation and a treatment plan, you will be able to manage the anti doping problem.
Think that an evaluation is a photo taken at a T moment. Exactly when you make a blood drawn, it is like a photo at a T moment.
It may change over the time. The test given during childhood may not be accurate any more.
So I won't encourage you enough about getting him a complete evaluation (not only an IQ test, but a complete evaluation). Also, if you are in need to fight for the anti doping stuff, it will be a powerful tool to help.
I will say that a complete evaluation is a master piece to fight in these kind of situations. Without it, it's preaching in the desert.
You said that he was evaluated as a child.
If I were you, I would make him evaluated to see what does he have exactly, and get him treated for what he has. Therapy may not be enough for him, and leaving him untreated does not improve anything, no matter what is the diagnosis.
Years passed on since he did the tests, and tests evolve with age.
If stimulants are right for him, it can help convincing the federation that he is given them because he needs them. If they are not the right solution
medically speaking, then, they are not the right solution medically speaking and it's not a problem.
Not treating the problem, whatever it is ADHD, BiPolar (BP), personality disorder etc... worsens the gambling problem more often than not. Not treating the problem because of fear of antidoping tests won't help him at all. The gambling is a way to self medicate his root issue.
So, to make my saying clear, and with the info you have just had provided to me (I understood before that he had been diagnosed with ADHD, my mistake), the first step is thinking to make him have a diagnosis and the proper treatment for his root problem. Because gambling is fueled by the root problem, whatever it is ADHD, BiPolar (BP), personality disorder etc... and if you want to deal with gambling, you cannot spare yourself from getting him diagnosed and treated for his problem.
Gambling and substance abuse is exactly the same pattern, so the history of substance abuse does not surprise me.
Also, if he has ADHD and is treated with stimulants, he will be much less likely abuse substance (as incredible as it seems). The same holds true if he has BiPolar (BP) and is medicated with a mood stabilizer etc etc...
The right medication/medications combo for a mental health condition is the most protective tool you can offer him to protect him against substance abuse and pathological gambling, along with therapy. But therapy alone is more often than not far from being enough.
If he gets a diagnosis of ADHD at the end and stimulants are not enough efficient/are abused/carry unacceptable side effects, I repeat that non stimulant medications can be used, and it exists. But if a non stimulant is inefficient, it makes no sense to keep it just because of anti doping rules.
If, after all the complete neuropsychologist evaluation, ADHD is diagnosed and a stimulant is prescribed, then, it will be time to deal with the administrative sport problem. But if he were taking a stimulant for an eventual ADHD, you would need the whole neuropsychologist evaluation for the therapeutic authorization.
But it may not even be needed if he does not take a medicine considered as doping. So you don't need to dwell about it right now, it is putting the cart before the horse right now.
Really, the first and foremost problem is having him properly diagnosed and treated. Then, you will have plenty of tools to deal with the anti doping rules problems and its administrative complications. At the moment, the anti doping concern is putting the cart before the horse.
The first and foremost priority right now is getting him evaluated and treated for his condition,
whatever the condition is and whatever the medicines he needs. Then, after you have had him evaluated, diagnosed and treated, you will be able to care about the anti doping rules administrative complications if this problem remains after he gets diagnosed and treated.
Don't put the cart before the horse by thinking about the anti doping problem. Instead, hyperfocus about getting him diagnosed and treated, because this is the first and foremost priority. Later, you will be able to manage the anti doping problem if it is still a problem after you got him evaluated, diagnosed and treated.
An administrative problem can always be solved by a way or another, even when it seems impossible to do so. That's also why I was telling you all this about the federation and such (the vast majority of administrative problems follow the same pattern and are solved by the main same solutions), and giving you these tricks I learnt.
But first and foremost, worry about getting him the proper diagnosis and treatment, then the anti doping problem can be solved. For your own sake and his, don't dwell too much about the anti doping problem, because it's not an emergency right now.
Instead, hyperfocus on getting him evaluated, diagnosed and treated for the root problem and pathological gambling.
Take things one day at time, you will be manage to solve all this on a way or another. Baby step after baby step, everything will get better.
Hang in there