Magical Mania (3.5e Flaw)
From D&D Wiki
Arcane energy has changed you, you have racing thoughts and speech.
Prerequisite: Ability to cast arcane spells.
Effect: Your thoughts are amplified by the arcane energy that flows through you, making them race through your head as you try to discern one thought from the other. This causes a -2 penalty to concentration checks and increases arcane spell failure - even when not wearing armour - for spells with verbal components by 10% due to the garbling nature in which you speak.
Benefit: 1 Bonus Feat.