I will be a dissenting voice and say this is not true. Madness is not creativity. Madness is malfunction. It is a mistake, a disorder, and a terrible blight. After it passes you can treat its debris creatively, but while you are going through it, madness is not only NOT creative, it ROBS you of your natural, hard-won creativity. It is a thief and a murderer, and it is unwise to romanticize it.