Feeblemind

A spell which is solely for employment against those persons or creatures who use magic spells, feeblemind causes the victim's brain to become that of a moronic child. 

The victim remains in this state until a heal, restoration, or wish spell is used to do away with the effects. The spell is of such a nature that the probability of it affecting the target creature is generally enhanced, i.e. saving throws are lowered.

Note that the spell has no material component.

Except as noted above, this spell is the same as the sixth level druid spell, feeblemind (q.v.). The material component of this spell is a handful of small clay, crystal, glass or mineral spheres.