Yes, and I would not recommend that your GM rule otherwise
As I was reviewing and commenting on other answers, I think I've determined that the answer to this question is yes. Furthermore, it might be unreasonable for a GM to suggest otherwise.
The general language used for conditions states the following (emphasis mine):
Conditions are persistent. Whenever you’re affected by a condition, its effects last until:
- the condition’s stated duration ends,
- the condition is removed,
- or terms dictated in the condition itself cause it to end.
The first criteria is what the condition's stated duration is. As the spell indicates that the duration is permanent, there is no hope of the duration ending on its own.
The next criteria evaluates the condition being removed. The spell stipulates the various ways that this can be achieved and they're probably not terribly viable for most parties in combat. 4 of them being 10th level spells and the remaining option being a spell with a 1 minute casting time.
So then we're left with the third criteria. Because the confused condition specifically indicates that it can be removed via a flat check whenever you take damage, this third criteria is applicable.
This third criteria also applies with regards to other conditions such as Fatigued or Doomed, which both state that they are removed or reduced, respectively, after a full night's rest. Additionally, it is helpful to look at the language used for the Frightened condition, which says that it reduces by 1 at the end of each turn unless otherwise specified.
The Fatigued condition is particularly interesting, because there are effects which stipulate that it can't be removed by the normal measures specifically. For example, the rules of Starvation and Thirst say:
Typically characters eat and drink enough to survive comfortably. When they can't, they're fatigued until they do. Without water, after a number of days equal to a creature's Constitution modifier + 1, the creature takes 1d4 damage each hour that can't be healed until it quenches its thirst. After the same amount of time without food, it takes 1 damage each day that can't be healed until it eats.
The Warp Mind spell lacks similar language stipulating that it can't be removed excepting for the spells listed therein, so the permanent duration stipulated only has the effect of ensuring the Confused condition won't just wear off with time, it will require an alternative.
But does that make sense?
Actually, it kind of does. The effects of the spell aren't minor. Even on a success, you're spending your turn confused and on a failure the duration is going to be a full minute. Note that there are not additional saves on this effect like the Confusion spell provides.
Looking at a few other offensive 7th level spells gives us an idea on the intended power level for the spell (I deliberately didn't include uncommon spells):
- Beheading Buzzsaw - This spell feels like an all or nothing spell. It deals no damage on a successful save and on a standard failure only deals 5d10 + 4d6 persistent bleed. The money is on a crit failure which triggers another fortitude save to avoid decapitation and even that is an incapacitation effect. Overall, probably a lot of effort that's not going to make a huge difference once 7th level spells roll out.
- Duplicate Foe - This spell gives a save and only on a failure does it really see its full potential whereby it effectively gives your team additional attack actions via a roughly equal leveled minion. Overall, though, this is just adding additional damage output for your team.
- Force Cage - Unlike the version in Dungeons and Dragons, this spell is not nearly as save or suck. The duration maxes at a minute, requires persistent use of the Sustain a Spell action, the cage can be broken, and it's also the version which has openings thus allowing you to attack out if you've the appropriate attacks.
- Prismatic Spray - Here we see some solid offense arrive in the form of complete randomness as all good prismatic spells should. Large amounts of flat damage that can be mitigated via reflex saves. If you get really unlucky, you're going to see some potentially nasty long-term effects, but you'll need to fail a few saves before that happens.
Overall, these effects strike me as things which aren't on the level of blow one save and you're done. You very well could die, but it seems like at a minimum you're going to have to fail at least 2 saves badly for that occur.
As such, it does not make sense to me for Warp Mind to have an effect with a single failure completely negating an enemy for the long-term. I think part of how this is handled will be dependent on how much the table metagames the effect.
Identifying a spell that was cast is generally not easy to do (at a minimum, you must spend an action to identify it and if you want to do it faster and reliably, you need to spend a skill feat and several proficiency boosts - notably for this to automatically identify you'll need legendary proficiency in the appropriate skill). Furthermore, there's nothing overtly obvious about the effect of the Warp Mind spell; if you do want to recognize that someone's confused in the middle of combat, you'd probably need to use the Sense Motive action but you notably need to have a Critical Success to understand that someone's being affected by magic; this might be hard to achieve until the GM sets a lower DC on the basis that the character has started attacking everything around them.
If the GM says that a character is confused, this spell's efficacy only really works if the players act as their characters would and do nothing because because barring another character informing them of the spell's effect, they shouldn't know.
They might have reason to do something when their good friend, Ragnar the Bone Smasher, begins smashing their bones. But that's going to be a full round of getting their bones smashed, which has a substantial impact on a combat encounter's action economy. If this spell is used wisely and targets someone in the middle of an enemy party, that's a lot more likely to cause an enemy's actions to be used for your group's benefit. It's benefits might feel a lot less useful if utilized on an enemy engaging your team's front line as half those actions might still come towards your team.
Regardless, this spell's effects trigger even on a successful save. This gets even worse on a failure. Either a failure or a critical failure pretty much obligates an opposing party to not only lose at least a full round of actions being directed towards it, then that enemy team is going to then need to figure out what's going on, land a successful attack on their ally, and have that ally succeed on the flat check in order to snap them out of it. And if they want to get out of that cycle fast their only choice is a 10th level spell.
So yes, the confusion ends upon succeeding on the flat check. But the situation first needs to occur that would trigger the flat check and a smart team using this spell would probably avoid attacking the confused character, instead focusing on the other opponents whom are dealing with the literal and figurative confusion that this spell has dropped into the middle of their ranks.