Although the focus of this book is elevated mood, any discussion of hypomania must include its interface with depression. Whether the appearance of depressed symptoms is discrete or concurrent with episodes of elevated mood, the diagnosis and treatment of elevated mood must take into account its relationship to depression. The prevalence of depression in patients with elevated mood occurs so frequently that this topic deserves special attention here. Depressive symptoms occurring simultaneously with elevated mood are covered both in this chapter and under mixed affective states in Chapter 8.

If one were to construct a “Top Ten List” of the reasons that patients with elevated mood present for mental health treatment, it might appear like the list in Table 4.1.

Because the presenting complaints of elevated mood, patients have not been systematically researched or quantified, experts might disagree on the exact order of this “top ten list,” but few would dispute that depression is, by far, the most common reason for presentation. Because evidence of elevated mood may be only commingled with symptoms of depression in patients with mixed states, or may only be historically evident but not present at the time of evaluation, careful diagnostic exploration is crucial.

Data gathered in several large-scale studies has shown that depression is extraordinarily common in patients with elevated mood. Judd, Akiskal et al. demonstrated that patients with bipolar I disorder spent an average
of one third of their time in a depressed state (1). Another study by this same group (2) showed that patients with bipolar II disorder spent at least half of their time in a clinically depressed state. In a naturalistic perspective, 7-year follow-up study of 908 patients with bipolar disorder, Suppes et al. looked for subtle signs of hypomania and depression as scored on the Young Mania Rating Scale and the Inventory of Depressive Symptomatology (3). Hypomania was present in 392 (43%) of these patients. In those patients with hypomania, 71% presented with depression mixed with hypomania during at least one visit. Overall, in 57% of the visits in which hypomania was present, depressive symptoms also occurred.

Bauer et al. (4) performed a cross-sectional analysis of 441 individuals with bipolar disorder treated at an American health maintenance organization and investigated the distribution of manic and depressive symptoms in that population. They found that clinically significant depressive symptoms occurred in 94.1% of those with mania or hypomania whereas 70.1% of those in a depressive episode had clinically significant manic symptoms.

Beyond the frequency of depression in patients with bipolar disorder, as documented by the studies mentioned in the preceding text, there is now evidence that depressed episodes incur a significant level of psychosocial impairment. Judd et al. (5) followed 158 patients with bipolar I disorder and 133 patients with bipolar II disorder for 20 years. Their findings suggest that any level of depression in patients with bipolar disorder is more disabling than any form of mania, further highlighting the necessity of identifying depression as well as elevated mood.

Perlis et al. (6) followed a subset of 1,469 patients who had been symptomatic for bipolar disorder with 58% achieved recovery. During a 2-year
follow-up period, 49% of those who had recovered subsequently experienced recurrences with twice as many patients developing depressive episodes as manic/hypomanic/mixed episodes combined. These episodes of depression also occurred significantly earlier than manic or hypomanic recurrences. Their data suggests that residual mood symptoms at the time of recovery are a “powerful predictor” of recurrence. The risk of a depressive relapse increased by 14% for every Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) depressive symptom still present at the time of recovery. This led the researchers to conclude “Overall, these results suggest that despite modern evidence-based treatment, bipolar disorder remains a highly recurrent, predominantly depressive illness.” Therefore, the principle of treating depression to full remission, the clinical goal for major depressive episodes, also appears to apply to depressive episodes within the context of a bipolar disorder.