Although there's a lot of material repeated from Steven Hassan's other two books I think there's enough new insight here to make reading this one worth your while. Here's a quote from the book that some might find encouraging.
In Freedom of Mind Steven Hassan wrote:
When interacting with your loved one in a cult, it is essential that you recognize the differences between the pre-cult identity (before recruitment), the cult identity (during membership), and the person's authentic self, which stays unchanged. Even people who are born into cults have an authentic self that was suppressed from birth. It is the strength of the authentic self that makes it possible to rescue people from cults many years, even decades after they join. When informed family and friends begin working as a team to educate their loved one about destructive influence, the cult identity and its barriers will begin to crumble.