The Diagnostic and Statistical Manual of Mental Disorders or DSM published by the American Psychiatric Association specifies four diagnostic categories and criteria for bipolar disorder. The diagnosis of which type it is depends on the symptoms a person presents with during an initial evaluation. The DSM-IV further defines specific subcategories or criteria for the diagnostic type to indicate level of severity of the most recent symptoms. The four types of bipolar disorder are bipolar I, bipolar II, cyclothymia and bipolar disorder not otherwise specified (NOS).
Bipolar I Diagnosis
Bipolar I disorder is primarily diagnosed in people who have episodes of depression and mania. The manic episode is severe and typically lasts from one week to several months while the depressive episode lasts at least two weeks. Mania is defined as a period of extreme excitement or elation when a person is more talkative than usual and thought patterns no longer make sense (typically termed as delusions or odd thinking). Grandiose ideas such as believing that nothing can go wrong or that one is superhuman are common during a manic episode. Often during mania auditory hallucinations can present as well as feeling paranoid that others are out to get the person. In extreme mania the person is no longer happily elated and excessive irritability occurs. Violence, promiscuity, and risk-taking behaviors are common symptoms when mania is experienced.
Depression can present either prior to or after the manic episode and is usually expressed through extreme tiredness, frustration with life and feelings of complete hopelessness. Depression is the exact extreme opposite of the mania experienced in bipolar I. Bipolar I is not just a normal mood shift, it is severe enough to be noticed as abnormal in the person presenting with symptoms.
Bipolar II Diagnosis
Extreme mania is not present in bipolar II disorder; however, a lesser mania termed as a hypomanic episode is displayed. Bipolar II is diagnosed when a person suffers from severe depression with one or occasional episodes of lifted mood or hypomania. Hypomania can impair functioning, but delusional or odd thoughts are not associated with this type. The fine line of difference between bipolar I and II is a clinician being able to tell that hypomania is present vs. full mania and recognizing that the depressive episodes are longer and more severe.
Cyclothymia and Bipolar Disorder NOS
Cyclothymia is the mildest form of bipolar disorder in both the hypomania experienced and the depression. A shift in ups and downs are required for a period of at least two years to meet this diagnosis and the symptoms are not as severe as indicated in bipolar I or II. In people with cyclothymia there are fewer breaks between the ups and downs, and it is common for symptoms to become worse and eventually meet criteria for bipolar disorder I or II.
Bipolar disorder NOS is diagnosed when the criteria for I, II, and cyclothymia are not met because symptoms do not last long enough or are not intruding enough to be deemed severe, yet they warrant a diagnosis due to being out of character for the person. The primary difference in cyclothymia and bipolar NOS is duration of time from onset of symptoms to diagnosis.
