Bipolar II Disorder - Diagnosis

Diagnosis

The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) recognizes two types of bipolar disorders—bipolar I and bipolar II. People with bipolar I disorder suffer from at least one manic or mixed episode, and may experience depressive episodes. On the contrary, as noted above, people with bipolar II disorder experience a milder form of a manic episode, known as a hypomanic episode as well as major depressive episodes. Although bipolar II is thought to be less severe than bipolar I in regards to symptom intensity, it is actually more severe and distressing with respect to episode frequency and overall course. Those with bipolar II often experience more frequent bouts of depressive episodes. Specific criteria defined by the DSM-IV for a bipolar II diagnosis is as follows:

• The presence of a hypomanic or major depressive episode.
• If currently in major depressive episode, history of a hypomanic episode. If currently in a hypomanic episode, history of a major depressive episode. No history of a manic episode.
• Significant stress or impairment in social, occupational, or other important areas of functioning.

Studies have identified major differences between bipolar I and bipolar II in regards to their clinical features, comorbidity rates and family histories. According Baek et al. (2011), during depressive episodes, bipolar II patients tend to show higher rates of psychomotor agitation, guilt, shame, suicide ideation, and suicide attempts. Bipolar II patients have shown higher lifetime comorbidity rates of DSM axis I diagnoses such as phobias, anxiety disorders, substance & alcohol abuse, and eating disorders and there is a higher correlation between bipolar II patients and family history of psychiatric illness, including major depression and substance-related disorders. The occurrence rate of psychiatric illness in first degree relatives of bipolar II patients was 26.5%, versus 15.4% in bipolar I patients.

Although the DSM-IV reports a bipolar II lifetime prevalence rate of 0.5%, recent epidemiological studies indicate a rate closer to 5% with one in two depressed outpatients suffering from this disorder. There are several reasons for this increase in bipolar II diagnoses. New semi-structured interviews allow trained research clinicians to diagnose a patient on the bipolar spectrum more accurately, DSM-IV criteria has relaxed so that now the minimum duration of hypomania is less than four days, and a history of hypomania is now focused more on over-activity, especially in regards to goal-setting activity, than mood changes. Screening instruments like the Mood Disorders Questionnaire (MDQ) are helpful tools in determining a patient's status on the bipolar spectrum and getting families involved can also improve chances of an accurate diagnosis and acknowledgment of hypomanic episodes. In addition, there are certain features that have been shown to increase the chances that depressed patients are suffering from a bipolar disorder including atypical symptoms of depression like hypersomnia and hyperphagia, a family history of bipolar disorder, medication-induced hypomania, recurrent or psychotic depression, antidepressant refractory depression, and early or postpartum depression.