An evolving literature exists concerning the nature of personality and temperament in bipolar disorder patients, compared to major depressive disorder (unipolar) patients and non-sufferers. Such differences may be diagnostically relevant. Using MBTI continuum scores, bipolar patients were significantly more extroverted, intuitive and perceptive, and less introverted, sensitive, and judgmental than were unipolar patients. This suggests that there might be a correlation between the Jungian extraverted intuiting process and bipolar disorder.
Does that mean that having Ne means a person may be bipolar?
I was myself recently diagnosed as bipolar. The psychiatrist told me I "intellectualized" too much, and gave me risperidone, an antipsychotic meant to control bipolar tendencies. I read over the wikipedia article on bipolar syndrome (and other sources besides) and I doubt I have it, as none of the descriptions match my behavioral patterns.
...I can say risperidone suppresses one's extroverted intuition, although it does not extinguish it entirely from what I can tell. (although I am taking only a milligram dose per day)