Individuals with bipolar disorder experience drastic depressive and manic mood episodes that alter normal energy and activity levels, sleep patterns and daily behavior, according to the National Institute of Mental Health. Many patients diagnosed with bipolar disease are symptom-free between episodes.
During a manic episode, individuals might be extremely happy or irritable, states the National Institute of Mental Health. They may also talk fast, experience racing thoughts, sleep only a little or engage in high-risk activities. During a depressive episode, individuals feel extremely sad, hopeless and lose interest in activities they normally enjoy. They might feel tired or restless and be unable to concentrate or make decisions.
Bipolar disorder is divided into four types, notes the National Institute of Mental Health. Individuals with bipolar I experience manic episodes that last at least seven days or necessitate immediate medical intervention due to the severity of the symptoms. They also experience depressive episodes lasting at least two weeks. Individuals with bipolar II experience depressive episodes, but they do not experience extreme manic episodes. Instead they experience hypomania, a less severe mood episode resulting in feeling good and being highly productive.
Individuals with bipolar disorder not otherwise specified, or BP-NOS, have symptoms of bipolar disorder that others recognize as abnormal, but do not meet the criteria of bipolar I or II, states the National Institute of Mental Health. Individuals with cyclothymic disorder experience episodes of hypomania and mild depression over a period of at least two years.