失张失智
shī​zhāng​shī​zhì

out of one's wits

  1. 失 shī verbadjective
    to lose control
    to lose control of oneself; to fail to restrain an action or emotion; to change from a normal state
  2. 张 張 zhāng adjective
    tense
    (bound form) Tense; strained
  3. 失智 shī​zhì
    to develop dementia
    To lose cognitive function; to suffer from a decline in mental ability due to brain damage or disease beyond what is expected from normal aging.