Yes and there is a good reason but not what you think though. They do not keep you out due to the Ritalin. They keep you out because the Ritalin usage requirement says a condition that requires it's usage is still there. It didn't leave at puberty. Meaning probable sensory problems. I passed two military physicals while only having vision in one eye at a time. That is a sensory problem. At the same time I was diagnosed in early childhood in mid 1960's with ADHD. I did not have it and my reaction to Ritalin pointed to that fact.
These type problems can mean anything from no depth perception to inability to properly hear and understand orders. The Ritalin usage is a flag for a underlying Neurological condition and nothing more. That is the big secret the military understands about Ritalin usage.
What a pile of cr@p. There is no scientific basis for that statement. If you've got one, name it.