http://en.wikipedia.org/wiki/Bipolar_disorder

[quote]
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[citation needed]. This suggests that there might be a correlation between the Jungian extraverted intuiting process and bipolar disorder.
[quote]

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)