No, this is not false. Reddit is all over posts about this. Any medication has risks how can you deny this? If you take it you accept this (admittedly) small risk.
Sorry, I responded to an exaggeration with one of my own. Mea culpa.
Of course every medication has risks. You should evaluate them for yourself, with a physician.
However, generalizing that to “medication is dangerous and can cause psychosis, or death, and thus you shouldn’t take it because it can have side effects, even if it could otherwise help you” is garbage advice.
Also, the dosages at which stimulants and such are used for ADHD as a therapy (as opposed to abused) are generally quite small, fwiw.