Cricket Wellington chief executive Peter Clinton said Ryder and his management requested the leave for the player to have some time away from top-level cricket, to concentrate on his wellbeing.
"It's no secret that Jesse's had a rough past fortnight, and the advice from professionals associated with his care is that he's just not in the right frame of mind for first-class cricket," Clinton said.
"We're very aware of the pressures that Jesse is under, and we support him taking a break if that's what's required to help him through this. We'll assist his return to the park when he's ready to go, and not rush him beforehand.
"While Jesse is a professional athlete and understands he has certain obligations to the fans, media and public, we'd ask that everyone gives him a little space now so that he can concentrate fully on getting himself ready again for professional cricket."
Ryder's manager Aaron Klee confirmed the decision to request leave from cricket was made between Ryder, himself, players' association boss Heath Mills and Ryder's clinical psychologist Karen Nimmo.