Stuttering and Bypolar Disorder

Stuttering and Bypolar Disorder So I have a friend who stutter and has bypolar disorder. At this moment he is experience a manic episode. He is very acelerated, has no filter or shame and talks crazy stuff. Well the thing is that when he is manic his stutter is gone. He can talk hours and hours to whomever and no holding back behaviour. He seems very confident, no signs of shame or fear or anything. I know is unreal because is the crazy doing all the talking but anyways it is very curious I wanted to share. ¿Any similar histories?