Is the prayer of one suffering from obsessive-compulsive disorder valid if he bases it on the minimum and does not perform the prostration of forgetfulness?

Whoever is afflicted by waswas (obsessive doubts) should base their actions on the most frequent occurrence, not the least. If they base it on the least frequent and perform what they doubted, their prayer is not invalidated, and they should prostrate after the salutation (prostration of forgetfulness).

Leaving the post-salutation prostration (of forgetfulness) does not invalidate the prayer; rather, one should perform it whenever they remember.

Therefore, the prayer of one afflicted by waswas is valid, and there is nothing against them.