Bipolar disorder is a severe psychiatric/psychological disorder that involves specific fluctuations of:
The eminent psychiatrist Emil Krapelin, who is considered the founding father of modern psychiatric diagnoses by many, first described a disorder known as manic-depression, which is the forerunner to the current conceptualization of what is now called bipolar disorder. For practical purposes, there is essentially no difference in the disorders associated with the diagnostic labels of manic depression or bipolar disorder; however, recent reconceptualizations of bipolar disorder and new knowledge have added information to this diagnostic category.
However, the actual diagnostic criteria associated with bipolar disorder and its subtypes essentially remain consistent with previous conceptualizations of the disorder.
In general, mania and hypomania are identified by the following features:
The formal diagnosis of clinical depression can only be made if at least five of the formal diagnostic symptoms are met consistently over two weeks, and one of the five symptoms is either the experience of sadness nearly every day or a loss of the ability to feel pleasure nearly every day. Typically, manic or hypomanic episodes are relatively short-lived (most often extend for a week or two without formal treatment), and depressive episodes last much longer (can extend for months at a time without treatment).
The major specifiers for bipolar disorder follow.
Two other potential categories of bipolar disorder relate to bipolar disorder-like symptoms that occur in response to the use of drugs or medications (substance/medication-induced bipolar and related disorder) or the symptoms result from some other medical condition (bipolar and related disorder due to another medical condition). For example, individuals who take large amounts of stimulant medications may exhibit alterations in mood that appear to represent formal manic episodes and depressive episodes, whereas individuals with certain types of head injuries or strokes may also display these symptoms.
Cyclothymic disorder is a longer and less intense manifestation of the symptoms that occur in bipolar disorder. Even though it is a separate diagnostic category, it is often considered by many to be a formal type of bipolar disorder, and it is listed by APA in the same overall category as other forms of bipolar disorder. This disorder consists of episodes of hypomania and depression that do not formally meet the criteria for bipolar disorder and continue for a period of two years or more.
APA recognizes several other types of bipolar disorder-like presentations that may be observed in clinical practice, but do not actually meet the formal diagnostic criteria for bipolar disorder:
Finally, in an effort to provide descriptive information to other clinicians and individuals who treat these disorders, the above diagnoses can sometimes be specified as either being mild, moderate, or severe in terms of their presentation. These designations are typically made based on the number of symptoms the individual formally presents with. Mild manifestations have fewer symptoms than moderate manifestations of bipolar disorder; moderate manifestations have fewer symptoms than severe manifestations of bipolar disorder.