When it comes to expressing doubt, there are several synonyms that can be used to communicate the same message. Words such as mistrust, skepticism, uncertainty, suspicion, and disbelief are just a few examples of synonyms for the phrase "cause doubt." These words signify a lack of trust or confidence, suggesting that the speaker is unsure about the truth or validity of something. Regardless of which word is used, the intention remains the same: to convey a sense of doubt or hesitation. It is important to choose the right synonym to effectively communicate one's doubts or reservations about a particular topic or situation.