NO, just depends on your program. 80% of anyone lifting will be the first to say, "If you squat more than once a week, you aren't doing it heavy enough!" That's a crock of shit. Those same fools load up 405 on the bar and do quarter squats!
I'm doing Bill Star's 5x5 using Madcow1's variation. Now...I do believe it IS impossible to do squats 3 times a week with the same heavy weight (ass to the grass). So what I do is: This is the way I begin every workout, not including the rest of what I do...
Monday: 5x5 olympic squats (same weight each set <heavy>)
Wednesday: 5x5 olympic squats (same weight each set <reduced 20% from Monday>)
Friday: 5x5 olympic squats (Pyramiding up. example- 185x5, 205x5, 225x5, ect)
This way I don't burn out. I'm actually going to make a thread about this for people to try.