Wow, I am going through similar questions with myself. I feel myself getting irritable over EVERYTHING. Someone will want to ask me a question about what book I'm reading, and I want to scream at them. There will be a small crowd at Target, and I'll want to leave. I find I am able to control my behaviors, but the feelings of irritation/annoyance FEEL overwhelming. From what I understand, irritability can be a sign of depression, mania, hypomania, OR a mixed episode(depressed and manic together). I've had a couple Drs think I had perhaps a mild bipolar disorder, others who disagreed with that. It's really confusing, so I'd like to know about the irritability thing too. I guess since it coudl be a symptom of different mood states, you could ask yourself about other symptoms in yourself, or about times in the past when you've been depressed or hypomanic and compare. Do you typically become irritable when feeling sad? Have you ever had a hypomanic episode? How long have you felt like this?