I know two people who appear to be “cured,” who grew up in dysfunctional abusive families. One sexually abused by a stepfather. The other verbally abused. Both improved as late teens, early adults after the abuser was no longer present in their lives. One had speech therapy and attributed a lot of his improvement to the accepting relationship he had with his speech therapist. The other seemed to improve naturally after the stepfather left the home. One seemed 100% fluent, and the other I only met once, but appeared completely fluent. I know one more who seemed to have a breakthrough of sorts while in a college speech therapy program . He was asked to speak to a class of speech therapy students. They intentionally, but without his knowledge, were rude, made ugly comments and provoked him. When he finally got fed up he lashed out in anger and was completely fluent. According to him that one incident made all the difference. He was an acquaintance but every time I spoke to him he seemed 100% fluent.