Quote From: mayzeegrlAlot of people are questioning whether they or someone they know has bipolar disorder. I know for me that I had questioned being bipolar to my ex-psychiatrist and she said that I didn't have the "highs". Therefore, I was not accurately diagnosed until some years later. I had been treated for depressions and that's what all the professionals thought I had, but the depression would never get better for long. Sometimes I would be "fine", able to perform well at my job and school, Take an interest in things. Feel like my brain was working. I wouldn't report any of this to my doctors because I felt that I was "normal" or "cured" and I would only report the depression and the crashes. Therefore, no one was getting an accurate picture of my moods.  
It wasn't until a short while ago that my therapist had me chart my moods. Basically, you write about how you are feeling, what your mood is like day to day. What you have been doing and so on, and then bring it with you to your doctors and therapist. I found from my mood journal that I had alot of ups and downs and it was able for me to see a pattern to my mood swings. 
You can also write up a chart for feelings---sadness, anxious, angry, happy, etc. and score them with 1 being a little to 5 being alot of how you feel with each emotion. You can also chart if you had felt suicidal or wanted to abuse substances. Anyways, it's worth a shot to bring up to your treatment team or to have a loved one try to track their moods. This way, it gives a pretty accurate description of peoples' moods.......I know that for me being accurately diagnosed finally, I've been able to have a more stable life because I'm on the "right" meds. (mood stabilizers) Good luck......... 
I just want to "echo" what has been said above and encourage anybody who has had a similar experience with depressive episodes (or love/know someone who has!), charting moods DAILY and sharing that info with a psychiatrist (someone who understands mood disorders if possible) may save you years of misdiagnosis. My husband was recently diagnosed with bipolar II disorder. He has had bouts of severe anxiety & depression for 10-15 years; has been treated with 6 different anti-depressants in 6 years. All of them seemed to give him some relief for 6-9 months, then would "stop" working and a debilitating depressive episode would occur. So, he would start a different anti-depressant and the cycle would begin again. One afternoon in December I finally wrote up a timeline of what had occurred and we took it to a new doctor for a second opinion. She looked over the timeline of treatment & then asked my husband about ever experiencing "hypomania" symptoms (periods of higher energy, thoughts coming faster than normal, etc.) The last piece fell into place. I do believe all his previous doctors had done their best to help him manage the depression and I understand better now how much they have to rely on the patient's symptoms...i just wish one of them would have thought to have him track his moods earlier!