Link: Hyperthymic Personality
Now, the better question would be, what if there is no depression? Can people just have mild mania? And the answer to that is at one level it appears that God or nature or Darwin or whoever evolved our brains or created our brains did it in such a way that it doesn’t seem that episodic, mild mania can happen by itself. It has not really been described that people can have intermittent hypomania and nothing else, no depression. It can happen, but it’s probably rare. Just having manic episodes without depressive episodes is reported in maybe 5 to 10 percent of bipolar patients, and we don’t really know if just having hypomanic episodes can happen.
Now, that being said, there is something else, and that is that there are many people that don’t have episodic hypomania, but they do have kind of a chronic hypomania. It’s part of their personality that they have high energy, a decreased need for sleep, high levels of activity, increased libido and so on. And the phrase that’s being used for them in recent years is hyperthymic personality. People may have heard of dysthymia, which is chronic low-level depression. That’s parts of the DSM-IV diagnostic system. But hyperthymia has not been part of that system. Sometimes people use the word cyclothymia for when patients go back and forth between low-level hypomanic symptoms and low-level depression symptoms.
But what a lot of people aren’t aware of is that there are people that have low-level hypomanic symptoms without any depressive symptoms. It’s part of their personality, hypothymia. What’s been found is that this kind of personality, hypothymia, is found much more in families of patients with bipolar disorder than in families of people who don’t have bipolar disorder. This suggests that maybe there is a genetic transmission of susceptibility to manic symptoms, where if you get a few genes you have hypothymia. If you get more genes, you get type II bipolar disorder, intermittent hypomania with depression. And if you have lots of the genes, you get full-blown mania.
So it may not be bad to have a few of the genes and have low-level hypomania or a hypothymic personality as long as that’s all you have. What frequently happens in these patients though is that they also have recurrent depressions. And if you also have depression and then get treated with an anti-depressant, which is traditionally the case, it’s a risk factor for getting manic. So once they get anti-depressants they can then have a severe manic episode.