As a therapist how should I treat these patients?
If one of your patient tells you they have Body Integrity Identity Disorder, or admits to having a deep need to acquire an impairment, whether it is to become an amputee, blind, paraplegic, deaf, or any number of other conditions, you should first make sure you understand Body Integrity Identity Disorder.
Then, you need to rule out psychosis, depression or other types of personality disorders.
You may be tempted to try a course of anti-depressants or anti-psychotics, but there is no study showing their effectiveness, and anecdotal evidence shows that they have very little result in treating transabled individuals.
It is interesting to note that psychotherapy also seems to be relatively pointless in treating BIID, although it is a useful tool to assist transabled individuals in gaining a better understanding of themselves and their condition.
Do note that admission of BIID feelings does not mean that the patient is at imminent risk of self-injury and should not give you a reason for hospitalisation. In fact, hospitalisation is not indicated unless the patient clearly states they are planning to injure themselves in the very near future.
See also Can't you just take a pill?