Working in combat conditions is one of those jobs that requires many people to pump adrenalin day in and day out; while others seem to be able to turn it on and off when needed. If anxiety and/or depression run in one’s family, then these high stress jobs make it even that more difficult. So during the stressful on the job rushes, the body and mind adapt, but the greatest risks come after the job/tour is finished and people return home. The adrenalin conditioned body continues to keep the body and mind in high-alert, but the person is not working-off/consuming that adrenalin. So this manifests in erratic behaviour.