How do doctors treat people who have factitious disorder?

The first goal of treatment is stop the person from abusing medical resources. Next, the aim is to ensure safety and protection of any real victims like children. The treatment for the individual resolves round stabilizing the psychosocial issues that are causing the problem. Psychotherapy may help change thinking and behavior. Medications are only used to treat secondary depression or anxiety. 

The prognosis of people with factitious depends on the duration of the illness. For those with short term problems, the prognosis is good but those with long term problem, the prognosis is poor. 

Most people continue their behavior and deny that they are faking symptoms. Some eventually end up with real medical problems which are never taken seriously.  Because the cause of factitious disorder is not known, prevention is not possible.