When in the depressed cycle, you can have any or all of the symptoms of a depressive disorder. When in the manic cycle, any or all symptoms listed under mania may be experienced. Mania often affects thinking, judgment, and social behavior in ways that cause serious problems and embarrassment. For example, unwise business or financial decisions may be made when an individual is in a manic phase. Bipolar disorder is often a chronic recurring condition.
Some people experience a few symptoms, some many.
Also, severity of symptoms varies with individuals. Some types of depression run in families, indicating that a biological vulnerability can be inherited. This seems to be the case with bipolar. Studies of families, in which members of each generation develop bipolar disorder, found that those with the illness have a somewhat different genetic makeup than those who do not get ill. Apparently additional factors, possibly a stressful environment, are involved in its onset.