Bipolar II disorder (BP-II) is a mood disorder on the bipolar spectrum, characterized by at least one episode of hypomania and at least one episode of major depression. Diagnosis for BP-II requires that the individual must never have experienced a full manic episode. Otherwise, one manic episode meets the criteria for bipolar I disorder (BP-I).Hypomania is a sustained state of elevated or irritable mood that is less severe than mania yet may still significantly affect the quality of life and result in permanent consequences including reckless spending, damaged relationships and poor judgment. : 1651  Unlike mania, hypomania is not associated with psychosis. The hypomanic episodes associated with BP-II must last for at least four days.Commonly, depressive episodes are more frequent and more intense than hypomanic episodes. Additionally, when compared to BP-I, type II presents more frequent depressive episodes and shorter intervals of well-being. The course of BP-II is more chronic and consists of more frequent cycling than the course of BP-I. Finally, BP-II is associated with a greater risk of suicidal thoughts and behaviors than BP-I or unipolar depression. Although BP-II is commonly perceived to be a milder form of type I, this is not the case. Types I and II present equally severe burdens.BP-II is notoriously difficult to diagnose. Patients usually seek help when they are in a depressed state, or when their hypomanic symptoms manifest themselves in unwanted effects, such as high levels of anxiety, or the seeming inability to focus on tasks.
The tendency for BP-II to be misdiagnosed and treated ineffectively, or not at all in some cases, leads to an increased risk.As a result of the high suicide risk for this group, reducing the risk and preventing attempts remains a main part of the treatment; a combination of self-monitoring, close supervision by a therapist, and faithful adherence to their medication regimen will help to reduce the risk and prevent the likelihood of suicide.Suicide is a common endpoint for many patients with severe psychiatric illness. The mood disorders (depression and bipolar) are by far the most common psychiatric conditions associated with suicide. At least 25% to 50% of patients with bipolar disorder also attempt suicide at least once. Aside from lithium—which is the most demonstrably effective treatment against suicide—little is known about contributions of specific mood-altering treatments to minimizing mortality rates in persons with either major mood disorders or bipolar depression specifically. Suicide is usually a manifestation of severe psychiatric distress that is often associated with a diagnosable and treatable form of depression or other mental illness. In a clinical setting, an assessment of suicidal risk must precede any attempt to treat psychiatric illness. Epidemiology
The global estimated lifetime prevalence of bipolar disorder among adults range from 1 to 3 percent. The annual incidence is estimated to vary from 0.3 to 1.2 percent worldwide. According to the World Mental Health Survey Initiative, the lifetime prevalence of BP-II was found to be 0.4%, with a 12-month prevalence of 0.3%.