DIABETES: Can very low blood sugars cause depression and make someone act like a different person?

Erratic blood sugars can cause mood swings, such as one would expect with untreated bipolar disorder. If you have ever gone for long periods without food and experienced a feeling of irritability as a result, magnify that, many times for blood sugars dropping suddenly too low. For such a person, It is suggested to get glucose into a more normal range.