Synonyms for Mistrust (same or very similar meaning)
WordNet sense 1 (doubt about someone's honesty):
distrust, misgiving, suspicionWordNet sense 2 (the trait of not trusting others):
distrustfulnessWordNet sense 3 (regard as untrustworthy; regard with suspicion; have no faith or confidence in):
suspect, suspectFrom the ODE community, based on WordNetadd/edit