There are no options, but I will still answer this question. A possible cause of bipolar disorder could be stress levels in your life. Depending on how stressed you are, you could be someone going through all types of things, but you're trying to stay positive, which can also contribute to your stress levels rising. Once things finally settle down, you could start being affected by the smaller things of life. You would then have anger issues, and if you don't get fixed, you could cause yourself to have bipolar disorder.
Sorry it's so long, but I hope that this answer helps you with your question!