Consumers increasingly are recognizing that depression is one of the most costly of all health problems. Employer-purchasers especially are concerned about depression because so much of the societal burden associated with this illness is related to adverse effects on workplace functioning. By the most recent estimates, based on year 2000 data, the total annual societal cost of depression in the United States is $83 billion, of which 62% is due to excess absenteeism and “presenteeism” (lower-than-average work performance).1
Many employers have responded to this situation by expanding depression outreach, treatment, and disease management programs. This has occurred at a time when many other factors have led to an increase in the proportion of workers with depression who have received treatment:
the introduction and aggressive promotion of direct-to-consumer advertising of new psychotropic medications with improved side-effect profiles2;
the development of new community programs aimed at promoting awareness, screening, and help seeking for mental disorders3; and
the expansion of primary care, managed care, and behavioral carve-out systems to deliver mental health services.4
These efforts collectively led to more than a tripling of the number of people who annually receive healthcare for depression in the United States in recent years compared with the late 1980s.5
The increased treatment of depression is encouraging in many ways. However, it also creates a major challenge for behavioral healthcare providers that must be recognized and met aggressively: that a much higher proportion of people with depression than previously realized suffer from an undetected and untreated bipolar spectrum disorder.6
Although bipolar disorder traditionally has been thought to have a lifetime prevalence of only about 1% in the general population,7,8 clinical and epidemiologic studies are leading to a substantial upward revision of this estimate. This revision is based on mounting evidence for the existence of a broad bipolar spectrum that includes not only hypomania, but also subthreshold manic symptoms and medication-induced manic symptoms.9-11 Although research is still incomplete, the available evidence suggests that this bipolar spectrum might characterize as much as 5 to 8% of the general population and, importantly, include a substantial proportion of the people who experience depressive episodes.6
The available evidence makes it quite clear that people with bipolar spectrum disorder spend a considerably higher proportion of their time with depressive rather than manic symptoms.12,13 This results in frequent confusion between depressive episodes that are part of a major depressive disorder and those that are part of the bipolar spectrum.14 This confusion, in turn, leads people with bipolar spectrum disorders to often be incorrectly treated as if they have nonbipolar depression because they present with depressive symptoms.15,16
Exacerbating this problem is the fact that people with bipolar spectrum disorder often report considerably more distress associated with their depressive symptoms than with their hypomanic symptoms.17 Incorrect treatment of bipolar depression with antidepressant medications can have dire consequences, including elevated risk of suicide, as well as increased healthcare costs.18
Because of these adverse consequences, it is important for behavioral health providers to screen for a history not only of bipolar disorders but also for a history of bipolar spectrum symptoms and family history of bipolarity at the onset of depression treatment. It would be prudent to avoid antidepressant monotherapy whenever there is any uncertainty regarding the existence of bipolarity. In addition, in light of their high prevalence, it eventually might be cost-effective to develop screening and outreach programs for people with bipolar spectrum disorders similar to the programs of this sort that exist for depression.
The major issues to consider in evaluating the cost-effectiveness of screening for bipolar spectrum disorders are the magnitude of the costs and the cost-effectiveness of currently available treatments in reducing these costs. The cost-effectiveness of treating bipolar I-II disorders is known to be quite high.19,20 However, the cost-effectiveness of treating subsyndromal bipolar spectrum cases is largely unknown. Effectiveness trials are needed to provide an answer to this cost-effectiveness question. The focus of these trials, as of recent depression effectiveness trials,21,22 might be on workplace costs of illness, given that so much of healthcare decision making is driven by institutional purchasers, although broader costs to patients, families, and society also need to be considered.