That's actually something that get many in the anti-gun crowd fired up, with the implication that the suicide wouldn't happen if the gun wasn't around.
I agree that the argument obviously isn't completely true, and may not be very true at all. However, more than half of suicides are by gun. There is a certain appealing simplicity and ease to suicide by gun that I can understand, when compared with cutting, or even pills if you don't know what you are doing (death by tylenol, for instance, is agonizing). It's quite possible that if guns were not available, the suicide rate might go down, and the survival rate of suicide attempts might go up.
This isn't an argument for gun control, ending suicide by ending gun ownership obviously won't work and probably shouldn't be done even if it did. There probably IS some truth to it however.