Bipolar disorder, sometimes known as manic depression, affects only about 1% of U.S. workers in a given year. Yet it costs the U.S. workplace $14.1 billion annually in lost productivity, according to a Harvard Medical School study. That's almost half as much as the productivity losses attributed to major depression, even though the latter disease is six times as prevalent. The study determined that each U.S. worker with bipolar disorder averaged 65.5 lost workdays in a year, compared with 27.2 for those with depression.
It is not the manic episodes that are the problem, says Ronald Kessler, a co-author of the report and professor of health care policy at Harvard Medical. In fact, mild forms of mania in workers suffering from bipolar disorder are sometimes seen as a plus. "People with these subthreshold manias can really be very productive," he says.
Depressive episodes cause the most damage. Kessler says that on any given day, about one-third of people in the workplace who are depressed are experiencing the downside of bipolar. In addition, these bipolar-generated depressive episodes are more severe and last longer than those of workers who suffer from depression alone.
Bipolar disorder, which often runs in families, is characterized by alternating episodes of mania and major depression, and it usually develops in the teens or early 20s. The mania is characterized by elation, irritability, excitability, racing thought and speech, and hyperactivity, whereas depressive episodes are characterized by sadness, withdrawal, despair, and suicidal thoughts.
Bipolar disorder is treated with a combination of behavior therapy and a number of different drugs, among them the anti-psychotics Zyprexa from Eli Lilly (LLY) and Risperdal from Janssen, a subsidiary of Johnson & Johnson (JNJ) (see BusinessWeek.com, 1/6/04, "A Cloud Over Antidepressants").
The Harvard study, funded by the National Institutes of Health, is the first to distinguish the impact on the workplace of depressive episodes caused by bipolar disorder from those attributed to major depression. Published in the September issue of the American Journal of Psychiatry, the study is based on a year of data collected from 3,378 employees who responded to a national survey. The productivity losses were calculated by combining days absent from work with how people felt they were functioning on the job.
The researchers discovered that some 75% of the bipolar respondents had experienced depressive episodes over the past year, and 63% also reported manic episodes. But the depressive episodes were the most persistent, lasting anywhere from 134 to 164 days, compared with 98 days for major depression.
One problem facing employers, says Kessler, is that bipolar disorder is often misdiagnosed and treated as major depression. But the antidepressants used to treat depression can actually trigger a manic episode in bipolar patients.
Kessler suggested that workplace mental-health programs should first rule out bipolar disorder when treating a depressed employee. But he says further studies are needed to determine the best return on investment for employers offering evaluations and treatment programs.