In a question/answer forum component I am writing as part of a site, I have two tables that theoretically look like this(that is, I want said data kept for each entity):

THREAD                 POST
thread_id              post_id   
type_id (question)     writer_id
writer_id              thread_id  
title                  parent_id
body (optional)        post_body
followers              date
merge_id               upvotes
date                   dnvotes
upvotes                replies
dnvotes                views
replies                post_type_id (e.g. answer, comment to an answer etc.)
views
anonymous

The only real differences between these entities are merge_id (if a question is merged into another one, this id will reference said question_id), followers, and title. Combining them into one seems a bit cumbersome and bloated to me, and seems to be starting off a bit denormalized I think. And, if they're one, both body and title would have to be be nullable which they shouldn't (I know there can be safeguards in the code).

I also thought of having thread consist of only the attributes not in post which would look like:

THREAD
thread_id (or post_id which would be primary and foreign key refing POST)
title
merge_id
followers

but that doesn't feel quite right either.

Also, if it makes any difference, I plan to have the questions displayed along with the highest ranking answer quite often, in the style of quora.

Any design advice would be much appreciated.

(also, I am keeping them someone generic (thread/post) so that if needed I can use these tables for a blog or whatever else later on.)