Perdo Mentem ha a selection of spells for impairing or harming the mind, but no listed spells to recover from these effects. There are new implied guidelines to be found among the spells beyond the core rulebook.
New Creo Mentem Guidelines
Base 20 – Cure or offset a malady or confusion, requiring a ritual to be permanent.
This was chosen as it is equivalent to a serious aging crisis, a disease, or a malady in the Creo Corpus spell guidelines.
Base 30 – Cure or offset insanity, requiring a ritual to be permanent.
Quoting Kid Gloves who said it well on the Ars Magica forums who found a reference to curing insanity – “Tales of Mythic Europe makes reference to curing Olivia of her insanity (p118). The text makes reference to a CrMe ritual that is the equivalent of healing an incapacitating wound to restore sanity, which would in turn allow the magi to get something resembling sense out of the ghost.”
This leads to two sample spell effects using those guidelines. One for the befuddlement, confusion, and memory degradation effects, and the other for the most severe mental malady – insanity.
Unbind the Beguiled Mind
Creo Mentem 25, R: Touch, D: Mom, T: Individual, Ritual
Permanently restores a mind from maladies and confusion, caused either naturally or unnaturally.
(Base 20, +1 Touch)
Restore the Shattered Mind
Creo Mentem 35, R: Touch, D: Mom, T: Individual, Ritual
Permanently restores a mind from severe maladies and insanity, caused either naturally or unnaturally.
(Base 30 which is equivalent to restoring an incapacitating wound, +1 Touch)
Both spell could be made as non-ritual, but would then not cure permanently, and also need additional levels of power to account for their longer non-permanent duration.
Ref: forum discussion.
More custom spells can be found in the New Spells for Ars Magica page.