Bipolar II disorder (pronounced "bipolar two") is a form of mental illness. Bipolar II is similar to bipolar I disorder, with moods cycling between high and low over time.
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 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
Rapid, "pressured," 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. 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.
The vast majority of people with bipolar II disorder experience more time with depressive than hypomanic symptoms. Depressions can occur soon after hypomania subsides, or much later. Some people cycle back and forth between hypomania and depression, while others have long periods of normal mood in between episodes.
Untreated, an episode of hypomania can last anywhere from a few days to several months. Most commonly, symptoms continue for a few weeks to a few months.
Depressive episodes in bipolar II disorder are similar to "regular" clinical depression, with depressed mood, loss of pleasure, low energy and activity, feelings of guilt or worthlessness, and thoughts of suicide. Depressive symptoms of bipolar disorder can last weeks, months, or rarely years.