How can one induce psychogenic death?
Leach's hypothesis is based upon case reports of prisoners of war subject to the most severe forms of incarceration and profound deprivation.  A minority of prisoners reportedly completely withdrew and ceased any form of goal directed behaviour (eating, drinking etc.).  Presumably, the prisoner's 'giving up' was in response to their self-evaluation that survival was impossible in the circumstances.
Leach, J. (2018). ‘Give-up-itis’ revisited: Neuropathology of extremis. Medical hypotheses, 120, 14-21. https://doi.org/10.1016/j.mehy.2018.08.009