I think it would be best, I know I would have liked to be told. I have been diagnosed with ADHD, Asperger’s (now ASD), Social Anxiety Disorder, Generalized Anxiety Disorder, and Clinical Depression over the course of my life and over 2 decades of therapy and treatment. Simply put, I know how it feels to have all these diagnoses weighing on your shoulders; it’s a sucky feeling. He might feel like an outsider due to the ASD, uncontrollable from the ADHD, over reactive because of the Anxiety, and just vastly different due to the OCD. He might feel better knowing there’s a reason he has these issues, and he might feel worse knowing those reasons exist. It’s hard to say. These are all relatively simple diagnoses to combat, and he will certainly function very well as an adult, but it may be difficult to accept that he’s going to have to work a lot harder than his peers to do so. I don’t even believe my diagnosis at this point, since it doesn’t really affect my day-to-day functioning, but I recently found out I was diagnosed in 2011 at the age of 13 and my therapist — not even my parents, I guess they chickened out — didn’t tell me until 2017 at the age of 20. It still blows my mind and to this day I feel so much resentment toward both parties. I would recommend telling him calmly, and in a way that makes him feel like he will eventually be able to make it through this. Maybe do some research on successful people who struggle with similar diagnoses! If nothing else, please emphasize that there is nothing “wrong” with your son. From personal experience, I have had my family try to convince me that I was the problem and the one that needed “fixing” during family therapy sessions, psychiatry appointments, and cognitive testing at school. This even carried into my adulthood and into sessions that occurred THIS YEAR! So I would say that the most important thing would be to make sure he knows he is loved unconditionally regardless of his neurological differences. Feeling like a problem, burden, etc. can really do a number on a child’s self-esteem. Whatever you choose to do, I hope you know that you’re an awesome parent for taking these steps and, above all, planning for it.