Bipolar Depression: Definition, Symptoms, Theoretical Onset Factors and Treatment

Bipolar depression, a component of bipolar disorder, occurs more often in women than in men. In general, the definition of bipolar I disorder is a mood disorder characterized by mixed episodes of mania and depression or mania itself. Bipolar II involves major depression along with slight mania called hypomania. The degree of bipolar disorder is defined by the most recent episode. As noted by the authors of Manic-Depressive Illness, F. Goodwin and K. Jamison, over half of bipolar diagnoses involve at least four recurring episodes. The first episode of bipolar disorder is defined as single manic episode according to Diagnostic Criteria from DSM-IV. Recurrent episodes of Bipolar are classified in one of five categories: depressed, manic, hypomanic, mixed, or unspecified.

Bipolar depression takes a huge toll on the personal and work life of individuals affected by it. In contrast to bipolar mania where a patient experiences the symptoms of heightened or irritable moods that last for at least one week, high energy, increased rate of speech, a surge of ideas, the belief that one has extra special powers, distractibility, and impulsiveness; bipolar depression results in sadness, worry, sluggishness, agitation, feelings of inadequacy, loss of appetite or interest in life's pleasures, and social withdrawal. Bipolar depression differs from major depression or unipolar depression in that it is a recurrent episode preceded by at least one manic or mixed episode, according to Diagnostic Criteria from DSM-IV.

Many studies and theories exist about the onset of bipolar depression. Interestingly, Diagnostic Criteria from DSM-IV reveals that, in women, bipolar depression can be caused by postpartum depression within four weeks of childbearing. Also, bipolar depression episodes can have seasonal patterns (depression reoccurring in the winter). The main theories of the causes involve genetics and neurotransmitters. As reported in the textbook Abnormal Psychology by Gerald Davidson and John Neale, genetics plays a significant role in bipolar cases since studies have found that 10-25 percent of the relatives of bipolar patients have suffered from a mood disorder. Further, the neurotransmitter theory states that a person with a low level of the neurotransmitter called norepinephrine is more likely to experience depression, while one with a high level is more likely to experience mania as supported by various studies.

Of final importance is the treatment for bipolar depression. Lithium is the most prevalent and effective bipolar medication when either depressive or manic episodes are present. Hospitalization is necessary when a patient is a danger to others or themselves in instances such as suicidal threats.

Sources

American Psychiatric Association (2000). Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), Text Revision. Washington, DC, American Psychiatric Association.

Davison, G.C., & Neale, J.M. (2001). Abnormal Psychology. New York: John Wiley & Sons, Inc.

Goodwin, F., & Jamison, K. (1990). Manic-Depressive Illness. New York: Oxford University Press.