An individual who is identified as having symptoms, perhaps related to PTSD or another mental illness, would typically be referred to a primary care physician for an initial assessment. Subsequently, there would be a referral made to the deployed mental health team, if there is one, such as we had in Afghanistan.
A decision would then need to be made as to whether the individual should be retained in theatre, perhaps returning to their unit to continue their mission, or perhaps doing another role, or be returned home for further care. That decision is made on an individual basis, based on the severity of the symptoms as well as the role that individual would play.