The diagnosis of bipolar disorder in people under 20 astonishingly increased 40-fold between 1994 and 1995 and 2002 and 2003, according to a study reported in this month's issue of Archives of General Psychiatry, the leading scientific journal in our field.
The Archives was not the first to report this story. Time magazine, always quick to spot a trend, was there first with a cover story on the subject in 2002 called "Young and Bipolar." It began with: "It used to be called manic depression. Now, this volatile form of mental illness is increasingly showing up in children and teenagers."
But is it? Perhaps the illness is being recognized where it was missed before. Alternatively, perhaps it is being overdiagnosed in kids who do not truly have bipolar disorder, but, instead, only have symptoms reminiscent of the illness.
Take Benny, for example (name changed for confidentiality). This 9-year-old was diagnosed with bipolar disorder in an outpatient setting based on things like constant irritability, being easily bored, sleeping less than usual and being bossy with people.
A systematic psychiatric evaluation revealed that, while he met the criteria for attention deficit hyperactivity disorder, and oppositional defiant disorder, Benny did not meet the strict criteria for bipolar disorder.
So, what exactly is bipolar disorder?
Here is the simple version: The term refers to two poles of mood — the low end, which is depression, and the high end, which, when severe, is called mania, and when milder, is called hypomania.
Some people with bipolar disorder love their hypomanias; the episodes can have them feeling elated and important, with a high energy level.
Manic episodes, on the other hand, typically veer out of control. These episodes are defined by thoughts that race so fast they cannot be reined in and by grandiose ideas, such as thinking God has chosen you to save the world. Manic moods can be highly irritable, and can shift dramatically at the slightest provocation.
To put these shifts into perspective, imagine listening to your iPod. Imagine you are in your 40s, and you typically listen to it at a normal volume. Your experience would be analogous to a normal mood.
If the volume is turned way down, it becomes much less interesting, which is analogous to depression. If a good song comes on, and you turn the volume up, it becomes more fun and exciting, which is like the experience of hypomania.
But, if you turn it up to the maximum, it becomes painful and unbearable, which is like what happens in the brain during mania.
Now for the complicated part: There are also bipolar mood states, called mixed states, where elements of the high and the low poles are mixed together at the same time.
Among the most common of these is the combination of the high energy state of mania with the low mood of depression. This can manifest as agitation, with patients wanting to hit, throw or break things, or as intense anger, leading to shouting matches with whomever is within earshot.
Some kids fulfill all the standard criteria for bipolar disorder. The controversy that exists in the diagnosis of bipolar disorder in children and adolescents surrounds the issue of how to categorize those who are disturbed, but in a way that does not conform to the classic bipolar picture.
In some, the problem is that their abnormal moods are primarily irritable, and they never get the elation that is most typical of the illness.
Others may experience elation, but only for hours at a time, rather than the four days required for hypomania, or the seven for mania.
In still other patients, the issue is distinguishing the impulsivity and agitation of bipolar disorder from disruptive behavioral disorders, such as those mentioned earlier: attention deficit hyperactivity disorder, and oppositional defiant disorder.
Ellen Leibenluft, a psychiatrist at the National Institute of Mental Health in Bethesda, Md., refers to this gray-area group as having "severe mood dysregulation," rather than bipolar disorder.
In last month's American Journal of Psychiatry, she and her colleagues compared rates of bipolar disorder in parents of children with bipolar disorder, and parents of children with severe mood dysregulation.
The rate in the former group was 18 times higher than that in the latter, suggesting that severe mood dysregulation may be a different animal than bipolar disorder.
What do children look like before they develop bipolar disorder? Liebenluft and colleagues reported last year that very few children with severe mood dysregulation develop bipolar disorder.
Our group at Johns Hopkins is part of a larger study examining adolescents whose parents have bipolar disorder, to determine whether there is a set of symptoms or illnesses that distinguish them, and whether there are factors or behaviors, such as drug and alcohol use, for example, that put them at greater risk of eventually developing bipolar disorder themselves.
Researchers will likely study this group's DNA to try to correlate genetic risk factors with patterns in the manifestation of illness.
The increase in the diagnosis of bipolar disorder in youth has, of course, led to increased prescribing of relevant medications, such as mood stabilizers and neuroleptics, for this group.
Another challenge we face is that little data currently exists on the effectiveness of these drugs in this age group.
One project, the Treatment of Early Age Mania study, being conducted at Johns Hopkins and other sites, including Washington University in St. Louis, is trying to help rectify this. The group aims to assess which medications are most effective in manic patients from age 6 to 15.
Their results should help us toward an increased level of confidence in prescribing decisions.
Dr. James Potash is an associate professor of psychiatry and co-director of the Mood Disorders Program (http://www.hopkinsmedicine.org/moods) at the Johns Hopkins School of Medicine in Baltimore, Md. If you have questions or comments, please e-mail at firstname.lastname@example.org. To participate in our studies, call 1-877-MOODS-JH.