paranoia

/ˌpæɹ.əˈnɔɪ.ə/
noun
  1. 1

    A psychotic disorder characterized by delusions of persecution, conspiracy and perceived threat against the person, often associated with false accusations and general mistrust of others

  2. 2

    Extreme, irrational distrust of others.

Antonyms

Source: https://en.wiktionary.org/wiki/paranoia