Feeblemind

The spell Feeblemind was a powerful charm spell that reduced a person's intelligence and personality to almost nothing. Arcane spellcasters were quite vulnerable to the effects of this spell, which were hard to remove.

Feeblemind was a common spell in the Realms.

History
The Netherese arcanist Hamring was given the credit for the creation of this spell in -1293 DR.