Bipolar Disorder is a serious psychiatric condition that manifests usually in the late teens and affects about one in fifty people. Afflicted individuals experience heightened and extreme states of mania or elation to severe depression, with one in six sufferers inclined to commit suicide. Researchers have discovered biological and genetic links to this illness. Environmental factors such as stressful situations and even diet have been revealed to trigger its onset to those who are biologically inclined to have it, or aggravate its symptoms to those who are already diagnosed with BPD. Bipolar Disorder is a psychiatric condition previously known as manic depression. It is a mental illness that influences how a person acts, feels and thinks. Generally, people with bipolar disorder experience a cycle of mood swings that range from elation to depression. The degrees of these mood swings likewise vary from mild to extreme. The experience of extreme elation is also known as mania.
Studies have shown an estimated one percent of the population develop bipolar disorder. Symptoms usually manifest itself in early adulthood. For many people with bipolar disorder, this condition usually lasts throughout their lives. The effects of bipolar disorder also extend to social and occupational aspects. Sufferers may withdraw from family and friends, and sometimes find themselves unable to work. There is a tendency for bipolar disorder to occur in sporadic episodes. Between episodes, the individual may experience no symptoms and function normally. About a third of them however may continue to experience mood difficulties or problems socially or with work between bipolar occurrences. People who have bipolar disorder often are not fully conscious of their condition. Those who fail to receive treatment may experience an average of four episodes in ten years. A minority of people with bipolar disorder (15%) may have many episodes in a year.
Bipolar disorder is brought about by both biological (brain chemistry) and genetic (history of the disorder in the family) factors, as well as lifestyle (stressors and diet) and environmental (mania in spring, depression in winter) factors. In other words, both “nature” and “nurture” influence the occurrence of bipolar disorder in people. This paper will examine the inter-relationship between the various “nature” and “nurture” factors, in giving rise to the onset of bipolar disorder in people (The Australian Psychological Society, 2008). It is estimated that more than two million Americans have it. Men and women are equally affected. Onset of the condition is usually during late teens. It is also estimated that an additional one million children and pre-teens are suffering from the early stages of bipolar disorder. Detection and diagnosis are at most times delayed.
Often people suffer for a decade before condition is diagnosed (Time Magazine – Young and Bipolar, 2002). In the United Kingdom, about half a million people are estimated to have bipolar disorder (University of Edinburgh, 2007). Bipolar disorder is a major psychiatric illness. According to a study in Australia, bipolar disorder affects around one in fifty people, and one in every six people with bipolar disorder will commit suicide (University of New South Wales, 2006). Biological Causes of Bipolar Disorder In the Seventh International Conference on Bipolar Disorder in June 2007, two studies have linked the brain as containing vital clues or markers for the diagnosis of bipolar disorder. Dr. Husseini Manji, chief of the laboratory of Molecular Pathophysiology at the National Institute of Mental Health suggested that bipolar disorder occurs as a result of abnormalities in neuronal plasticity cascades.
This is the complex machinery inside new cells which regulates various processes in the human body. Disruptions in these pathways were discovered to lead to many of the primary symptoms of bipolar disorder. Dr. Mary Phillips, Director of Functional Neuroimaging in Emotional Disorders at the Western Psychiatric Institute and the Clinic of the University of Pittsburgh Medical Center, has discovered patterns of abnormalities in the neural systems that bring about emotional processing and cognitive control uniquely attributed to the bipolar brain (University of Pittsburgh Medical Center, 2007). In Time Magazine’s interview with Dr. Wayne Drevets of the National Institute of Mental Health, five parts of the human brain were described to have abnormal activities in the bipolar brain.
The Ventral Striatum is that which helps the brain process rewards. In the bipolar brain, this Ventral Striatum is over-active, with about 30% less gray matter in this region. The resulting behavior is a loss in judgment for certain behaviors such as overspending or being indiscriminate. The Prefrontal Cortex, or parts of it, regulates emotion. It is also vital in processing motivation and rewards. In the bipolar brain, braches that supposedly connect neurons are lost, leading to a 20-40% reduction of gray matter. The Amygdala is one of the brain’s emotional centers. It helps in the identification of facial expressions and tones of voice.
When a person is emotionally stimulated, neural transmissions increase. When a person is repeatedly exposed to the same stimulating images or experiences, habituation or reduced response occurs. In the bipolar brain, habituation the repeated stimuli occurs slowly, thus the brain remains reactive even beyond the usual response period. The Hippocampus is one of the brain’s centers of memory. The subiculum, a layer of the hippocampus, helps recognize circumstances that represent reward or danger. In the bipolar brain, the branches that connect neurons are lost. Thus leading to a constant state of anxiety since the person can no longer identify situations that are safe. The nucleus in the brain stem contains the serotonin cell bodies.
These create and disperse the neurotransmitter to various sections of the brain. In a bipolar brain, there is 40% less serotonin receptor in the nucleus. The resulting atrophy of neurons usually lead to depression (Kluger & Song, 2002). People with bipolar disorder and schizophrenia have been discovered to have overactive protein kinase C (PKC) enzymes. This enzyme impairs higher brain functions, according to a study of Yale University in 2004. This study tested the effects of increased PKC activity in the prefrontal cortex of animals that performed working memory tasks. The regulation of thoughts, behaviors and feelings all takes places in the prefrontal cortex region of the brain. Bipolar disorder and schizophrenia renders the prefrontal cortex dysfunctional.
Direct or indirect activation of PKC in animals dramatically impaired functions of the prefrontal cortex. PKC triggers the cognitive symptoms as a response to stress. When the chemical norepinephrine, the stress-sensitive messenger, binds to cell membrane receptors in the prefrontal cortex, the PKC is activated through a cascade of events. The PKC enzyme thus travels out to the cell membrance, opens the ion channels which heighten the cell’s excitability, and strokes the protein machinery which propels neurotransmitters into the synapse. Inhibition of PKC on the other hand, protected the prefrontal cortical function. For cognitive tasks that did not rely on the prefrontal cortex, no changes in performance were observed (NIH/NIHM, 2004; Yale University, 2004).
This particular research results contributes to the mounting evidence of that excessive activity of the PKC may cause distractibility, impulsivity, disturbed thinking and impaired judgment seen in people with schizophrenia and bipolar disorder (Yale University, 2004). In Australia in 2006 scientists at the Garvan Institute of Medical Research and the University of New South Wales discovered the first risk gene specifically associated with bipolar disorder.
People with this particular form of gene are twice as likely to develop the disease. Studies with families, unrelated patients and therapeutic drug mouse models led to the discovery of this gene called FAT – a gene related to the connection of brain cells. The research’s initial findings pointed that the popular lithium treatment for bipolar disorder exerts a therapeutic effect by altering FAT gene expression and also alters the expression of genes encoding FAT’s protein partners.
This particular research on the FAT gene continues to discover further how it functions, to be able to develop better diagnostic tests and treatment (University of New South Wales, 2006). Genetic factors of Bipolar Disorder It is unlikely that scientists will expect genes to tell the whole story about major psychiatric diseases. However, the persistent frequency of mental illness in one percent of the international human population, across ethnic and cultural differences, and its tendency to manifest itself in families point to a strong genetic link (Johns Hopkins Medical Institutions, 2003). Scientists have reason to believe in that bipolar disorder can be passed on to next generations of families genetically.
In “gene penetrance,” families susceptible to certain illnesses develop it differently throughout generations. It is more common-place that later generations suffer worse than previous generations due to a genetic mechanism known as “trinucleotide repeat expansion.” Each time genes are inherited, defective sequences of these genes grow longer. This results in descendants coming down with the illness. Trinucleotide repeat expansion has been associated with Huntington’s disease, and evidence is currently mounting to this genetic condition increases the risk of having bipolar disorder as well. The National Institute of Mental Health has worked with eight research centers around the United States to study genomes of 500 families with a history of bipolar disorder to examine what genetic quirks are shared.
Ten out of forty-six human chromosomes were discovered to show irregularities that may be linked with bipolar disorder. Chromosome 22 is the most interesting of which. This same chromosome has also been associated with schizophrenia, and velo-cardio-facial syndrome. All these disorders are related by patients’ experience of delusions (Kluger & Song, 2002). Environmental triggers of Bipolar Disorder Environmental factors in itself are not believed to singularly cause bipolar disorder in people. Dr. Michael Gitlin, Head of the Mood Disorders Clinic at the University of California in Los Angeles says that most doctors and scientists do not think environmental stress causes bipolar disorder. But these factors can trigger the condition in people who are already vulnerable (Kluger & Song, 2002).
Like many latent emotional disorders such as alcoholism, anxiety conditions, depression, bipolar disorder can also be triggered by major life events such as death, divorce, losing one’s job, or rights of passage such as moving out to start college, marriage, birth of a child. These and other situations that cause stress and anxiety are believed to trigger bipolar disorder (Kluger & Song, 2002). The Yale University study has also revealed thatt mild stress can activate PKC, and thus contribute to the worsening of symptoms in patients already with bipolar disorder and schizophrenia. The link between outside stress as stimulating the PKC can thus be used to explain deterioration of higher brain function, and why bipolar disorder and schizophrenia patients are most susceptible to dysfunctions that are stress-induced (Yale University, 2004).
Dietary factors and ingested substances as triggers to Bipolar Disorder What a person eats and drinks are also believed to trigger bipolar disorder. Caffeine triggers mania for those with bipolar disorder. Teens are thus advised to stay away from coffee and tea. Children already diagnosed with bipolar disorder must avoid caffeinated foods such as chocolate and sodas. Teens and adolescents must avoid alcohol and drugs. The risks for addiction to these substances by bipolars is substantially higher, and treatment for bipolar disorder will be much more difficult since the patient’s mind is already clouded by these recreational chemicals (Kluger & Song, 2002). Lead poisoning was discovered to have links with distractibility and impulsivity that are evident in children with bipolar disorder.
Even low levels of lead can activate the PKC enzyme, thus impairing the individual’s self regulation of his/her behavior. (Yale University, 2004). Lizzie Simon has bipolar disorder. She has written a book about her condition entitled “Detour,” which even inspired an MTV Special entitled “True Life: I’m Bipolar.” Time Magazine featured excerpts of her book, describing the first significant onset of bipolar disorder symptoms when she was seventeen years old, and her particular circumstances during this time. She was in Paris on her senior year abroad. She was having a wonderful time, and remembered thinking that she had never been this happy for this long in her entire life. She then received a letter of early admission to Columbia University.
Early the next morning, after such a perfect day prior, she felt insane. She experienced an uncomfortable light fuzz building up in her head. She described the feeling as if her jeans were too tight and her shoes were too big, but in her head. She remembered her place ride home for Christmas, and getting intoxicated with a guy in the last row. At that point for Lizzie, things started to fade. Between Christmas and New Year, she felt drifting and drowning. Her walls swooned. She documented in her journals thoughts of suicide attempts, experiences of being broken- hearted, sadness and other dark experiences. After receiving an initial treatment of Paxil, an anti-depressant, Lizzie returned to Paris and brought her pills with her.
In Paris, Lizzie was in a manic state. She remembers sitting in a café on a sunny day, then standing up and announcing loudly that she was going to walk until she got laid. Lizzie experienced many more psychotic episodes from manic to depressive during this period – sitting in her bedroom and thinking that there were microphones everyone, expecting killers to enter her room, feeling that the Mona Lisa was smiling at her, thinking she was a cat infested with bugs. She even bit her hand until she broke her own skin. At one time, she was about to jump off a terrace, only to be disrupted by the ringing of her phone. She remembered the caller being a woman who sounded like her mother. But she then thought then it was the CIA.
She sought treatment at the American Hospital in Paris. She was advised to stop taking Paxil, and was diagnosed to have bipolar disorder. She flew home and later on, started taking Lithium (Simon, 2002). It is interesting to note that Lizzie Simon’s grandfather had bipolar disorder. Since her family kept it a secret, Lizzy had no idea of this particular aspect of her family history until after she was diagnosed, and after the symptoms developed into more severe forms. He was diagnosed the year she was born. Lizzie was diagnosed the year her grandfather died (Simon, 2002). This is not an issue of nature versus nurture. What the evidence points out is more of a “nurture enhancing nature” inter-relationship. Although numerous studies have shown that there are people who are predisposed biologically and genetically to bipolar disorder, external factors such as events, stress and even diet can not only trigger bipolar disorder.
These factors can also worsen the symptoms of already diagnosed bipolar patients. Lizzie Simon’s story is just one of thousands of incidents of people inheriting the genes that lay the foundation of bipolar disorder, the prominent symptoms of which are triggered by emotional and stressful external events and circumstances. In the same manner, people with bipolar disorder, or those who are most inclined to develop this condition (having parents or grandparents with bipolar disorder) can prevent its occurrences, or at least lessen the severity of its symptoms, depending on how they personally manage stressful situations in their lives.
The principle of external and environmental factors as triggering the onset, or worsening the symptoms of bipolar disorder is already widely accepted internationally. But studies to better understand the details of these inter-relationships of “nature” and “nurture,” particularly to develop better diagnostic tests and treatments are on-going. References Australian Psychological Society (2008) What is Bipolar Disorder? Retrieved January 1, 2008 from http://www.psychology.org.au/community/bipolar/ Johns Hopkins Medical Institutions (2003, April 1).
Families With Severe Form Of Bipolar Disorder Help Scientists Narrow The Search For Disease Genes. ScienceDaily. Retrieved January 2, 2008, from file:///C:/Documents%20and%20Settings/April%20Santos/Desktop/Essay/4%20Bipolar%20Disorder%20$40/Families%20With%20Severe%20Form%20Of%20Bipolar%20Disorder%20Help%20Scientists%20Narrow%20The%20Search%20For%20Disease%20Genes.htm Kluger, J. & Song, S. (2002) Young and Bipolar. Time Magazine. Retrieved January 1, 2008 from http://www.time.com/time/magazine/article/0,9171,1101020819-336003,00.html NIH/National Institute Of Mental Health (2004, November 3). Stress Impairs Thinking Via Mania-Linked Enzyme. ScienceDaily. Retrieved January 2, 2008, from file:///C:/Documents%20and%20Settings/April%20Santos/Desktop/Essay/4%20Bipolar%20Disorder%20$40/Stress%20Impairs%20Thinking%20Via%20Mania-Linked%20Enzyme.htm Simon, L. (2002). Everything was perfect…and then I went insane. Time Magazine. Retrieved January 1, 2008 from http://www.time.com/time/covers/1101020819/detour.html University of Edinburgh (2007, July 21). Manic Depression Linked With Brain Tissue Loss. ScienceDaily. Retrieved January 2, 2008, from file:///C:/Documents%20and%20Settings/April%20Santos/Desktop/Essay/4%20Bipolar%20Disorder%20$40/Manic%20Depression%20Linked%20With%20Brain%20Tissue%20Loss.htm University of New South Wales (2006, January 13). FAT Chance Of Becoming Manic-depressive. ScienceDaily. Retrieved January 2, 2008, from file:///C:/Documents%20and%20Settings/April%20Santos/Desktop/Essay/4%20Bipolar%20Disorder%20$40/FAT%20Chance%20Of%20Becoming%20Manic-depressive.htm University of Pittsburgh Medical Center (2007, June 9). Brain Holds Clues To Bipolar Disorder. ScienceDaily. Retrieved January 2, 2008, from file:///C:/Documents%20and%20Settings/April%20Santos/Desktop/Essay/4%20Bipolar%20Disorder%20$40/Brain%20Holds%20Clues%20To%20Bipolar%20Disorder.htm Yale University (2004, November 5). Enzyme Linked To Mania And Schizophrenia Impairs Higher Brain Functions. ScienceDaily. Retrieved January 2, 2008, from file:///C:/Documents%20and%20Settings/April%20Santos/Desktop/Essay/4%20Bipolar%20Disorder%20$40/Enzyme%20Linked%20To%20Mania%20And%20Schizophrenia%20Impairs%20Higher%20Brain%20Functions.htm