Iam not talking from a scientific standpoint, i tried weed from my friends in the us both indica and sativa it makes sleepy, calm indeed but i just want to not move or do any kind of activity. Cannabis made me lucid quick thinking i used to smoke before philosophy class , math class tp help me stay sharp and not get distracted, same for the people around me who used it they used it to calm their anxiety and feel more in peace, this is not me encouraging or saying that it cure stuttering. What im saying is it used to get me to the point when im calm and able to say every fucking word with never thinking about using a synonym or anticipate a blocking.