https://www.reviveresearch.org/blog/an-unrecognized-symptom-of-bipolar-disorder-rage/

People with bipolar disorder may say hurtful things due to the impulsivity, intense emotions, and reduced insight that occur during mood episodes, particularly mania. Hurtful words can stem from irritability and anger in manic states or the overwhelming sadness and hopelessness in depressive states. These statements are often not intentionally cruel but are symptoms of the disorder, and they can be reduced with proper treatment, therapy, medication, and strong communication with loved ones.