If you do then you need to define why & when. I personally don't want to see a culture of blocking people off because certain other people on NMP don't like to see their posts. We've been through all this so many times on here and with some it has got to the point of calls for bans and I don't believe it is always about the person's health and more about certain people not liking certain things as can be seen with arguments like "for the good of the forum" which just reminds me of "think of the children".
Simple. Don't post. Let those who want to, do.
Reassurance is certainly an issue but change how you reply. Replying is not just feeding something, unless everyone thinks every doctor and therapist is also an enabler?
You may also want to think about deleting, or rather censoring, the replies of others. It could isolate the OP and it will likely annoy the person taking their time to help too.