Bipolar Disorders Depress Productivity

BOSTON, Sept. 1 -- Bipolar disorders cause twice as much lost time in the workplace as does major depression, according to a national mental health survey.

Workers with bipolar disorders who were surveyed reported losing an average of 65.5 lost work days a year, primarily during the depressive phase of the disease, reported Ronald C. Kessler, Ph.D., of Harvard Medical School, and colleagues in the Sept. 1 issue of the American Journal of Psychiatry. In contrast, people with major depressions lost an average of 27.2 work days annually.

Most of the lost productivity among employees with bipolar disorders came from longer and more severe episodes of depression than those of workers with major depression, the authors found in a subgroup analysis.

The findings have implications for the study of mood disorders in the workplace, and for employee assistance programs, noted Philip S. Wang, M.D., Dr.P.H., also of Harvard, a co-author.

"Major depressive episodes due to bipolar disorder are sometimes incorrectly treated as major depressive disorder," said Dr.Wang. "Since antidepressants can trigger the onset of mania, workplace programs should first rule out the possibility that a depressive episode may be due to bipolar disorder."

The authors used data from the National Comorbidity Survey Replication, which is conducted every 10 years to gauge the mental health of the nation.

The survey used the World Health Organization's Composite International Diagnostic Interview to assess the prevalence of major depressive disorder and bipolar disorder, and measured work impairment with the WHO's Health and Work Performance Questionnaire.

The investigators performed a regression analysis of major depressive disorders and bipolar disorder predicting Health and Work Performance Questionnaire scores among 3,378 workers to estimate workplace costs of mood disorders.

They found that 1.1% of all 3,378 respondents met the Composite International Diagnostic Interview criteria for 12-month bipolar I or II disorders, and 6.4% met the criteria for 12-month major depressive disorder.

People with bipolar disorder had an average of 65.5 lost workdays per year, with 27.2 for those with major depressive disorders. More of the lost productivity was due to degradation of performance on the job than to absenteeism, the investigators found.

When they projected the estimates of lost productivity to the U.S. workforce as a whole, they found that bipolar disorders could account for as much as 96.2 million lost workdays and .1 billion salary-equivalent lost productivity per year. In contrast, major depressive disorder may account for 225 million lost workdays and .6 billion salary-equivalent lost productivity per year.

In a subgroup analysis, the authors also found that bipolar disorder with major depressive episodes was consistently associated with more lost productivity than bipolar disorder with only manic or hypomanic episodes. Lost productivity among workers with only manic/hypomanic episodes was comparable to that of workers with major depression.

Persistence of depression was also significantly higher among people with bipolar disorders (mean 134.0-164.0 days, median 90-150 days) than in those with major depressive disorder (mean 98.1, days, median 60.0 days; P=0.01).

"Employer interest in workplace costs of mood disorders should be broadened beyond major depressive disorder to include bipolar disorder," the authors wrote. "Effectiveness trials are needed to study the return on employer investment of coordinated programs for workplace screening and treatment of bipolar disorder and major depressive disorder."