If diabetes isn’t taken care of, can it cause mental issues? Can it cause someone to become schizophrenic or bipolar or just have random fits of anger?

Uncontrolled diabetes can affect a person’s mood and may make someone feel more irritable, tired or burned out, and could possibly cause someone to feel more angry like you described. Individuals with diabetes are also at a two to three times higher risk of being diagnosed with depression. I do not know of any correlation of uncontrolled diabetes causing schizophrenia or bipolar disorder, although there has been a correlation found between certain psychiatric medications causing weight gain, which can lead to type 2 diabetes.

I also want to stress that it is very important to take care of a person’s diabetes for both their short term and long term health. I would recommend that the person you are asking about meet with a health care team, which may include a mental health counselor (clinical psychologist or clinical social worker) that is knowledgeable about diabetes, to assess for any mental health difficulties.

DB