Hypomanic episodes do not go to the full extremes of mania (i.e., do not usually cause severe social or occupational impairment, and are without psychosis), and this can make bipolar II more difficult to diagnose, since the hypomanic episodes may simply appear as periods of successful high productivity and are reported less frequently than a distressing, crippling depression. Cyclothymia: A history of hypomanic episodes with periods of depression that do not meet criteria for major depressive episodes.When relevant, specifiers for peripartum onset and with rapid cycling should be used with any subtype. Individuals who have subthreshold symptoms that cause clinically significant distress or impairment, but do not meet full criteria for one of the three subtypes may be diagnosed with other specified or unspecified bipolar disorder. Other specified bipolar disorder is used when a clinician chooses to explain why the full criteria were not met (e.g., hypomania without a prior major depressive episode). If the condition is thought to have a non-psychiatric medical cause, the diagnosis of bipolar and related disorder due to another medical condition is made, while substance/medication-induced bipolar and related disorder is used if a medication is thought to have triggered the condition. Rapid cycling
Most people who meet criteria for bipolar disorder experience a number of episodes, on average 0.4 to 0.7 per year, lasting three to six months. Rapid cycling, however, is a course specifier that may be applied to any bipolar subtype. It is defined as having four or more mood disturbance episodes within a one-year span.
Individuals experiencing a mixed state may have manic symptoms such as grandiose thoughts while simultaneously experiencing depressive symptoms such as excessive guilt or feeling suicidal. They are considered to have a higher risk for suicidal behavior as depressive emotions such as hopelessness are often paired with mood swings or difficulties with impulse control. Anxiety disorders occur more frequently as a comorbidity in mixed bipolar episodes than in non-mixed bipolar depression or mania. Substance (including alcohol) use also follows this trend, thereby appearing to depict bipolar symptoms as no more than a consequence of substance use. Comorbid conditions
People with bipolar disorder often have other co-existing psychiatric conditions such as anxiety (present in about 71% of people with bipolar disorder), substance abuse (56%), personality disorders (36%) and attention deficit hyperactivity disorder (10–20%) which can add to the burden of illness and worsen the prognosis. Certain medical conditions are also more common in people with bipolar disorder as compared to the general population. This includes increased rates of metabolic syndrome (present in 37% of people with bipolar disorder), migraine headaches (35%), obesity (21%) and type 2 diabetes (14%). This contributes to a risk of death that is two times higher in those with bipolar disorder as compared to the general population.Substance use disorder is a common comorbidity in bipolar disorder; the subject has been widely reviewed. Causes
The causes of bipolar disorder likely vary between individuals and the exact mechanism underlying the disorder remains unclear.