What psychologists now call “bi-polar” used to be called “Manic-depressive” because people with this problem swing (to one degree or another) from very depressed to very hyperactive and “manic.”
Wiki says about bi-polar http://en.wikipedia.org/wiki/Bipolar_disorder
Bipolar disorder (also known as bipolar affective disorder, manic-depressive disorder, or manic depression) is a psychiatric diagnosis for a mood disorder. Individuals with bipolar disorder experience episodes of a frenzied state known as mania, typically alternating with episodes of depression.At the lower levels of mania known as hypomania, individuals appear energetic and excitable and may in fact be highly productive. At a higher level, individuals begin to behave erratically and impulsively, often making poor decisions due to unrealistic ideas about the future, and may have great difficulty with sleep. At the highest level, individuals can experience very distorted beliefs about the world known as psychosis. Individuals who experience manic episodes also commonly experience depressive episodes; some experience a mixed state in which features of both mania and depression are present at the same time. Manic and depressive episodes typically last from a few days to several months and can be interspersed by periods of “normal” mood.Current research suggests that about 4% of people experience some of the characteristic symptoms at some point in their life. Prevalence is similar in men and women and, broadly, across different cultures and ethnic groups. Genetic factors contribute substantially to the likelihood of developing bipolar disorder, and environmental factors are also implicated. Bipolar disorder is often treated with mood stabilizing medications and psychotherapy. In serious cases, in which there is a risk of harm to oneself or others, involuntary commitment may be used. These cases generally involve severe manic episodes with dangerous behavior or depressive episodes with suicidal ideation. There are widespread problems with social stigma, stereotypes, and prejudice against individuals with a diagnosis of bipolar disorder. People with bipolar disorder exhibiting psychotic symptoms can sometimes be misdiagnosed as having schizophrenia.
Bi-polar is frequently undetected, and according to one study,
Even in psychiatric settings, bipolar disorders usually go undetected, or recognized only after a long delay. A significant proportion of not only bipolar II, but also bipolar I patients are never hospitalized. Polyphasic episodes and rapid cycling are prevalent in both types. Depressive mixed states are at least as common among bipolar II patients as mixed episodes among bipolar I. Bi-polar disorder is also frequently found in people who also have other psychological problems, including Attention Deficit, Hyperactive Disorder and in people with anti-social/psychopathic personality disorder. This frequently makes diagnosis very difficult. There is a genetic tendency for this which can be passed on from parents to children, but there are also environmental aspects too.
Treatment can be very helpful, both with medication and with psychological therapy. Without treatment, people with bi-polar can, during episodes of mania, break the law and wind up in the criminal justice system.
If you suspect that someone you love is experiencing episodes of mania and/or depression, early treatment is much more beneficial than when they have already broken the law. Unfortunately, too, many people with bi-polar are resistant to treatment, and it is suspected even like the “manic” stage in which they feel that they can accomplish anything, no matter how hair-brained the scheme which might easily land them in jail or prison.