Bipolar Affective Disorder

"Mood" is defined as a ubiquitous and sustained feeling or emotion that dominates a person’s behavior and affects his perception. Mood disorders also known as affective disorders include unipolar and bipolar disorders. Hippocrates was the first to distinguish between different dispositions or humors--melancholic, choleric, phlegmatic, sanguine--but it was Jules Farley in 1854, who first described folie circulaire or the alternating cycle of euphoria and melancholia. In 1899, Emil Kraepelin then further elaborated upon this burgeoning nosological distinction as he distinguished the psychosis observed in manic-depressive disorders from that of dementia praecox (i.e. schizophrenia). Manic-depressive disorder--more contemporarily identified as bipolar disorder (BD)--is a chronic and complex disorder of mood that is characterized by a combination of manic, hypomanic, and depressive episodes, with subsyndromal symptoms extant in between the mood episodes. It is one of the leading causes of worldwide disability and morbidity. BD has been frequently associated with serious medical and psychiatric comorbidity, early mortality, high levels of functional disability, and compromised quality of life. BD can be further subdivided into bipolar disorder I (BD I) and bipolar disorder II (BD II). The quintessential feature of BD I is the manifestation of at least one manic episode--although depressive episodes are common, only one manic episode in a lifetime is enough to label one with BD I. To be diagnosed with BD II, one must experience at least one hypomanic episode, without any history of any manic episodes. Both of these aforementioned manifestations must precipitate in the absence of any substance, iatrogenic agent, or organicity as such extant associations would be indicative of the diagnoses of 'substance/medication-induced bipolar and related disorder' and 'bipolar and related disorder due to another medical condition', respectively. Additionally, a less elucidated derivative of the bipolar spectrum is 'cyclothymic disorder' which is more analogous to a personality disorder in its chronicity and pervasiveness.