SRD:Panicked

Panicked
A panicked creature must drop anything it holds and flee at top speed from the source of its fear, as well as any other dangers it encounters, along a random path. It can’t take any other actions. In addition, the creature takes a –2 penalty on all saving throws, skill checks, and ability checks. If cornered, a panicked creature cowers and does not attack, typically using the total defense action in combat. A panicked creature can use special abilities, including spells, to flee; indeed, the creature must use such means if they are the only way to escape.

Panicked is a more extreme state of fear than shaken or frightened.