Mania is a defining feature of bipolar disorder. As a result, the condition often includes mood swings between periods of depression and manic episodes that interfere with a patient's cognitive functioning. Medication is the most common treatment for mania.
It's pretty common for someone to say, "You're deluded," when you believe something the other person doesn't believe. For example, if I were to say that I'm sure store-bought tomatoes are as good as home-grown, you might well tell me I'm deluded (or that I've never tasted a home-grown tomato). However, if I believed home-grown tomatoes…