It's absolutely manageable with medication and good therapy.
The medication is there to get them calm enough so the therapy can do it's work. But the medication will probably also be something they need to take their whole lives. The worst seems to happen when people go off their medications, in my experience.
There is also now genetic testing that can be done before prescribing medication so you can know exactly the best biological pathways that your body has. In essense, which drugs are most easily metabolised by your body.
This gives psychiatrists a better path to finding a good set of drugs that can help instead of going in scattershot. Knowing which drugs will be best metabolised by your body avoids wasting time on drugs that don't metabolise well.
I strongly suggest the genetics testing for this and I stress the importance of finding a good therapist your son trusts.
You're welcome. The company my psychiatrist used to do it is called GeneSight if that helps at all.
Be careful though, they have a lot of negative reviews about people's doctors saying it is covered and then getting a bill for services. I did not have that experience, mine was definitely fully covered and I have not received a bill. Check with your insurance to be sure, and if you're open to paying it out of pocket, it sounds like $300 to $500 is about the cost most people pay when insurance doesn't cover it.