Is it permissible for one afflicted with obsessive doubts (waswas) to ignore the rules of doubt—such as doubting the number of prostrations (sajadat) or units of prayer (rak'at)—in order to get rid of these obsessive thoughts, or must he adhere to them?

The rulings concerning doubt apply to the average person who is not afflicted by waswas (definition) (obsessive whispering). As for the one afflicted by waswas, they should disregard these whispers and pay them no attention; for doubt after an action has no effect, and similarly if doubts become frequent. If you are prone to frequent doubts and you doubt whether you performed one prostration or two, then disregard the doubt and consider it to be two prostrations. And if you doubt whether you recited or not, then proceed on the assumption that you have recited.