About bipolar disorder
Bipolar disorder (also known as manic-depressive disorder) is a chronic illness so named because sufferers experience intermittent mood episodes of two extreme poles - mania (which may include symptoms such as episodes of elevated moods, extreme irritability, decreased sleep and increased energy) or depression (which may include overwhelming feelings of sadness and suicidal thoughts), or a combination of both (mixed episode).1
In fact, the IMPACT study shows that up to 64% of patients experience depressive symptoms during a manic episode.
The impact of bipolar disorder
The condition can result in damaged relationships, difficulty working, going to school or participating in regular activities.1 Those with bipolar disorder are part of a medically-burdened population and often experience multiple complications, e.g. cardiovascular disease is one of the leading causes of premature mortality in this population.1,2
Always seek advice from your own doctor should you experience any of the above described symptoms.
- Bipolar disorder affects close to 30 million worldwide, including over four million people in Europe3
- Bipolar disorder is the sixth leading cause of disability worldwide4
- Bipolar disorder affects 1-2% of the population and affects men and women equally5
- The average age of onset of bipolar disorder is 25 years6
- Bipolar disorder is a major and underestimated health problem in Europe. Costs are mainly due to long term indirect costs associated with comorbidities, suicide, early death and unemployment as well as direct costs including hospitalisation during episodes7
The spectrum of bipolar disorders
The spectrum of bipolar disorders includes bipolar I disorder and bipolar II disorder:8
- Bipolar I disorder is defined by severe manic or mixed episodes that last at least seven days. Sufferers rarely experience symptom free periods and often have some residual depressive symptoms between episodes. These residual symptoms are not enough to qualify for a diagnosis of a mood episode, yet they may contribute greatly to impaired functioning in the daily life of a person suffering from a manic episode.10 Sufferers may also experience depressive episodes, typically lasting at least two weeks.1
- Sufferers of bipolar II disorder primarily experience severe depression with occasional episodes of mild mania known as hypomania.8
The cause of bipolar disorder
The exact cause of bipolar I disorder is unknown, but it is likely caused by a combination of several factors, including:9
- Biochemical imbalance
- Genetic predisposition
- Environmental factors
Defining a mixed episode
According to the previous Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), a mixed episode must meet the full criteria for a major depressive episode and a manic episode nearly every day for at least one week.11
However, this is considered restrictive as mixed episodes rarely conform to these qualifications, yet in clinical practice many patients complain of either depressive features during a manic episode or manic features during a depressive episode.
Therefore, updates were made to DSM-5 which allow for mixed states to be described more practically as any combination of depressive and manic symptoms, using a specifier indicating the presence of symptoms of the opposite pole.12 This is applicable to episodes of both depression and mania and in the context of both unipolar and bipolar lifetime diagnoses.
The specifier indicates that you can have:12
- A manic or hypomanic episode with mixed features: if full criteria are met for a manic or hypomanic episode and at least three depressive symptoms are present during the majority of days of the current or most recent episode of mania or hypomania.
- A depressive episode with mixed features: if full criteria are met for a major depressive episode and at least three manic/hypomanic symptoms are present during the majority of days of the current or most recent episode of depression.
- National Institute of Mental Health. Bipolar Disorder 2009. Available at: http://www.nimh.nih.gov/health/publications/bipolar-disorder/nimh-bipolar-adults.pdf. Accessed August 2012.
- Osby U, et al. Excess mortality in bipolar and unipolar disorder in Sweden. Arch Gen Psychiatry. 2001; 58: 844-850.
- World Health Organization. Global Burden of Disease. Available at: http://www.who.int/healthinfo/global_burden_disease/GBD_report_2004update_part3.pdf. Accessed August 2012.
- Kleinman L, et al. Costs of bipolar disorder. Pharmacoeconomics. 2003; 21: 601-622.
- Oswald P, et al. Current issues in bipolar disorder: a critical review. Eu Neurophsychopath. 2007; 17(11): 687-695.
- Kessler R, et al. Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication (NCS-R). Arch Gen Psychiatry. 2005; 62(6): 593-602.
- Liberty F, et al. A Systematic Review of the Evidence of the Burden of Bipolar Disorder in Europe. Clin Pract Epidemol Mental Health. 2009; 5: 3.
- Depression Bipolar and Support Alliance (DBSA). Guide to depression and bipolar disorder.
- Depression and Bipolar Support Alliance (DBSA). Guide to Depression and Bipolar Disorder 2002. Available at: http://www.dbsalliance.org/pdfs/guide1.pdf. Accessed August 2012.
- Bonnin CM et al. Subthreshold symptoms in bipolar disorder: impact on neurocognition, quality of life and disability. J Affect Disord. 2012 Feb: 136(3):650-9
- American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders Fourth Edition(DSM-IV),2000.
- American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5), 2013, pp. 149 -150.