I want to second genetic testing! I had it done for myself after taking medicine for depression for years without it helping, and my doctor and I were able to find something that has helped me a lot.
I'm not sure if there's different companies that do it, but just so you have a name, the one I used was Genesight. I think my insurance told me that they wouldn't cover it, so I was able to get it for free.
Hi, I'm currently engaged to a wonderful man who I love very much. He is diagnosed with both ADHD and bipolar disorder, and has been since he was a kid. He's had a long time for him and his doctor to experiment with which medications work well for him and get him stable, and so, to be very honest, I don't think I really notice much of anything that I attribute to his bipolar. If he had never told me about it and had only mentioned his ADHD, I don't think I would have ever known.
I'll admit that I don't know very much about bipolar, so it's very possible that maybe my fiance is lower on the "spectrum" (if one exists - I personally have depression and autism so this is where my first hand experience lies) than your son, but like you mentioned, your son is early in his journey compared to where my fiance is at. But I want you to know that there is definitely hope, especially with parents who love and care for him - and you must, since you're here asking about him.
If this is your first experience with mental health care, it might be advantageous to research groups in your area for help. For instance, in my area there's NAMI, which was a big help for my fiance's mother when he got his diagnosis.
If you'd like to ask more questions about my experience, feel free to shoot them my way!
More relevant than ever: 
Looks like his desk is a great place to use the bathroom instead!
I do think that medication is key, and luckily my fiance is very dedicated to taking his pills diligently. If your son is seeking treatment, then that's a great step in the right direction. And with your support, I think he will definitely be on the right path. Best of luck! I'll be rooting for him and you :)