Antonyms for the phrase "giving peace of mind" may include phrases such as causing anxiety or worry, creating unrest or unease, stirring up emotions, or provoking apprehension. These antonyms convey a sense of discomfort or discord, which is the opposite of the calming effect that "giving peace of mind" creates. Other antonyms could include phrases such as causing chaos, confusion, or disorder, which can create a sense of disarray and uncertainty rather than a feeling of calmness and assurance. Overall, the antonyms for "giving peace of mind" can vary depending on the context and the specific emotions or reactions that the opposite phrase evokes.