I was reading this thread and tried clicking on the threads linked therein and they don’t work. The format is completely different, the link points to an html page. Is there a way to convert or are the linked threads gone forever?
The threads are probably still there. But as you found out, the links don’t work because of the format change. There’s no way to convert them now.
As it happens, the first link gave the correct thread title. “Search on titles only” with the keyword “psychosis” turned up the thread: http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=7049&highlight=psychosis
Otherwise, you’re stuck with standard keyword search and it’ll be hard to figure out if you’ve found the correct thread.
Also, on old threads some of the posts are out of order - probably GMT vs. Central Time - so the OP may be a few posts from the top.