However, in bipolar II disorder, the "up" moods never reach full-blown mania. The less-intense elevated moods in bipolar II disorder are called hypomanic episodes, or hypomania.
A person affected by bipolar II disorder has had at least one hypomanic episode in his or her life. Most people with bipolar II disorder suffer more often from episodes of depression. This is where the term "manic depression" comes from.
In between episodes of hypomania and depression, many people with bipolar II disorder typically live normal lives.
Virtually anyone can develop bipolar II disorder. About 2.5% of the U.S. population suffers from some form of bipolar disorder - nearly 6 million people.
Most people are in their teens or early 20s when symptoms of bipolar disorder first start. Nearly everyone with bipolar II disorder develops it before age 50. People with an immediate family member who has bipolar are at higher risk.
What Are the Symptoms of Bipolar II Disorder?
During a hypomanic episode, elevated mood can manifest itself as either euphoria (feeling "high") or as irritability.
Symptoms during hypomanic episodes include:
Flying suddenly from one idea to the next
Having exaggerated self confidence
Rapid, "pressured" (uninterruptable) and loud speech
Increased energy, with hyperactivity and a decreased need for sleep
People experiencing hypomanic episodes are often quite pleasant to be around. They can often seem like the "life of the party" -- making jokes, taking an intense interest in other people and activities, and infecting others with their positive mood.
What's so bad about that, you might ask? Hypomania can also lead to erratic and unhealthy behavior. Hypomanic episodes can sometimes progress onward to full manias that affect a person's ability to function (bipolar I disorder). In mania, people might spend money they don't have, seek out sex with people they normally wouldn't, and engage in other impulsive or risky behaviors with the potential for dangerous consequences.