Bipolar disorder: What you need to know

By Vicky Nguyen 

Blog Team Lead

Bipolar disorder is a neurological condition that includes a wide range of disorders. According to the National Institute of Mental Health [1], bipolar disorder is categorized into 2 categories: bipolar I, bipolar II, and cyclothymic disorder (or cyclothymia). While bipolar I is distinguished by manic or mixed episodes alternating with several depressive episodes, bipolar II features one or more hypomanic episodes with one or more major depressive episodes. Meanwhile, cyclothymic disorder is characterized by repetitive hypomanic and depressive symptoms that are not intense enough to be labelled as hypomanic or depressive episodes.

Symptoms of bipolar disorder

Symptoms of bipolar disorder typically include mood episodes of intense emotions, changes in sleep patterns and activity levels, and unusual behaviours [1]. The duration of these traits lies in the range of one to several days and varies between individuals. While people experiencing manic episodes exhibit a surge in energy, racing thoughts, and excessive appetite, those with depressive episodes have difficulties sleeping, making decisions, and generating interest in almost all activities [1].

Physiological mechanisms

The physiological mechanisms behind bipolar disorder have been long associated with the function of three neurotransmitters: norepinephrine, serotonin, and dopamine [2]. Early models postulated that reduced levels of norepinephrine and dopamine caused depression, while increased amounts of both neurotransmitters were responsible for mania. For example, Wightman and Robinson [3] concluded that heightened dopamine emission overlaps with electrical activities at cell bodies, stimulating reward processing in the brain and increasing motivation. Therefore, a lack of dopamine correlates with motivated behaviours, which are typical in patients exhibiting depression in bipolar disorder [3].

Furthermore, the symptoms of bipolar disorder frequently occur in adolescence and early adulthood, with the risks for mania doubling during the early to late teen years [4]. To establish the estimated lifetime prevalence of bipolar disorder, a National Comorbidity Survey replication by Kessler et al. [5] studied over 9,000 adults in the United States. The study demonstrated that the lifetime risk for bipolar I or II disorder in adults aged 18-29 is 22 times higher than in the senior cohort (over 60 years), thus solidifying the tendency for bipolar disorder to be more prevalent in younger age groups.

Available treatments
Treatment is accessible through mood stabilizers, such as lithium and valproate and cognitive behavioural therapy, which offers patients guidance and support [6]. Due to widespread stigma and lack of awareness towards bipolar disorder, many people with bipolar disorders do not attempt to seek support or treatment. A survey of members of the Depression and Bipolar Support Alliance (DBSA) revealed that as much as half of the patients did not seek care for 5 years and accurate diagnosis was not available until an average of eight years after the first attempt of treatment [7]. Henceforth, a more holistic approach to understanding bipolar disorder is needed to ensure the well-being of those in need.

Numerous studies were conducted on the treatment of bipolar disorder to improve its outcomes. Meta-analyses of commonly prescribed treatments dating from the 1970s are especially common, but few produced consistent results to compare their efficacies. Addressing this problem, Cipriani et al. [8] published a meta-analysis, which examined 68 randomized control trials involving 16,073 participants from 1980 to 2010, to determine the efficacy of various medications for bipolar disorders at therapeutic dose ranges. The conclusions revealed the high efficacy of antipsychotic drugs, which include risperidone, olanzapine, and haloperidol, in addressing manic episodes for bipolar patients [8]. The results, which offered valuable insights for clinicians to choose from many treatment regimens, shed hope on finding more effective and appropriate medications for patients.

Furthermore, studies have shown that understanding and awareness from patients’ families can considerably prevent relapse in bipolar disorder. In a qualitative interview study conducted by Peters et al [9], individuals with bipolar disorders indicated positive outcomes when their relatives were trained to monitor their symptoms and provide in-home support. The study also identified barriers to relative involvement in routine care, especially engagement and privacy. These results highlight the need for frequent communication between patients’ relatives and healthcare professionals, who could offer support to care for patients [9]. Thus, further research into the dynamics between people with bipolar disorder, their families, and healthcare professionals can better facilitate relapse prevention.

Conclusion
Bipolar disorder, which encompasses bipolar I, bipolar II, and cyclothymia, is a condition that is characterized by intense mood changes, disruption in daily activities, and unusual behaviours. The underlying biological mechanisms of bipolar disorder involve changes in the activity of neurotransmitters, with depression caused by reduced levels of norepinephrine and dopamine, while increased amounts of both neurotransmitters are responsible for maniac episodes. Despite its impacts, bipolar disorder can be addressed by mood stabilizers, family care, and community awareness. More research into bipolar disorder with an emphasis on holistic care can bring hope to patients and their families, contributing to a more enriching understanding of the condition.

References

1. National Institute of Mental Health [internet]. Bethesda MD: National Institutes of Health; c2024. Bipolar Disorder; 2024 Feb [cited 2024 Aug 14]; [about 8 screens]. Available from: https://www.nimh.nih.gov/health/topics/bipolar-disorder
2. Manji HK, Quiroz JA, Payne JL, et al. The underlying neurobiology of bipolar disorder. World Psychiatry. 2003;2(3):136-46.
3. Wightman RM, Robinson DL. Transient changes in mesolimbic dopamine and their association with ‘reward’. Journal of neurochemistry. 2002 Aug;82(4):721-35. doi: 10.1046/j.1471-4159.2002.01005.x. PubMed PMID: 12358778
4. Miklowitz DJ, Schneck CD, Singh MK, et al. Early intervention for symptomatic youth at risk for bipolar disorder: a randomized trial of family-focused therapy. J Am Acad Child Adolesc Psychiatry. 2013;52(2):121-31. doi:10.1016/j.jaac.2012.10.007
5. Kessler RC, Berglund P, Demler O, Jin R, Merikangas KR, Walters EE. Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication. Archives of general psychiatry. 2005 Jun 1;62(6):593-602. doi:10.1001/archpsyc.62.6.593
6. Miklowitz DJ, Johnson SL. The psychopathology and treatment of bipolar disorder. Annu. Rev. Clin. Psychol.. 2006 Apr 27;2(1):199-235. doi: 10.1146/annurev.clinpsy.2.022305.095332
7. Hirschfeld RM. Bipolar spectrum disorder: improving its recognition and diagnosis. Journal of Clinical Psychiatry. 2001 Jan 1;62:5-9.
8. Cipriani A, Barbui C, Salanti G, Rendell J, Brown R, Stockton S, Purgato M, Spineli LM, Goodwin GM, Geddes JR. Comparative efficacy and acceptability of antimanic drugs in acute mania: a multiple-treatments meta-analysis. The Lancet. 2011 Oct 8;378(9799):1306-15. doi: 10.1016/S0140-6736(11)60873-8
9. Peters S, Pontin E, Lobban F, Morriss R. Involving relatives in relapse prevention for bipolar disorder: a multi-perspective qualitative study of value and barriers. BMC psychiatry. 2011 Dec;11:1-0. doi: 10.1186/1471-244X-11-172
10. Cover image
    Youngson N. A tablet showing a dictionary definition of bipolar disorder. [2017 Feb 25]. Available from: https://commons.wikimedia.org/wiki/File:Bipolar_disorder.jpg

About the author

Vicky Nguyen is the Team Lead for the STEM Fellowship Blog Team. A second-year undergraduate student studying Integrated Sciences at the University of British Columbia, she is interested in neuroscience, physiology, and public health. Vicky is currently conducting research in women’s sexual health, where she is investigating genito-pelvic pain and sexual disorders. In her free time, she enjoys learning new languages, reading history, and writing poetry.