The longest I've had off was a year and a half. I was really stable leaving as it was summer and the stress of school wasn't a problem. I was actually in a pretty crazy happy mood all that summer. But a month or so before school came in, I slowly went back to my old ways and then plummeted. I didn't go back for a few more months, which was a mistake, and ended up pretty bad. Finally, after my friends were pleading with me, I decided to go back, and my T welcomed me with open arms. I didn't try another T during my break, though, but my T wouldn't have mind, I would guess.