Your question is a very important one, but it’s not an easy one to answer.
As you may know, surveys of people living with bipolar disorder find that many people experience severe symptoms for 10 years or more before receiving a diagnosis of bipolar disorder. In many cases, people receive years of treatment for depression before someone realizes that depression is really part of bipolar disorder.
The “textbook” picture of bipolar disorder includes clear manic episodes with euphoria or elevated mood. That kind of bipolar disorder is easier to recognize. But most people with bipolar disorder don’t experience that “textbook” picture. It’s more common to experience mixtures of symptoms (feeling depressed while also feeling increased energy, racing thoughts, decreased need for sleep). Or people may experience more rapid mood shifts between feeling depressed and slowed down to feeling irritated and speeded up. Those more mixed or rapidly changing types of bipolar disorder are not as easy to recognize.
There are some things that should make us think more about bipolar disorder (instead of just unipolar depression): a family history of bipolar disorder, experiencing rapid mood shifts, and not seeing benefit from several different antidepressant medications. Information from family members or friends is often helpful. They may be able to see patterns over time: periods of increased energy, decreased sleep, or appearing speeded up.
DBSA has online tools that can be helpful. Our Wellness Tracker can help you to keep track of things that might indicate bipolar disorder: not needing to sleep, feeling irritable or speeded up, doing impulsive things (like over-spending or driving too aggressively). Using that tool—and bringing it with you when you visit your doctor or therapist—can really help you to make better decisions about next steps.