Biological Causes Of Bipolar Disorder Psychology Essay

Biological Causes Of Bipolar Disorder Psychology Essay Bipolar disorder is likely one of the most difficult diagnoses to receive in terms of living a normal life. As a psychological disorder, or more specifically, a mood disorder, its typical age of onset is in the early twenties, and its prevalence is between one and two percent worldwide. The disorder is characterized by an alternation between mania and depression, as well as poor impulse control, attention deficits, and impairments of verbal memory. Intensity of the manic state in a bipolar patient determines whether they are diagnosed with bipolar I or bipolar II. Those with classic, full-fledged mania have bipolar I, where as those with a less extensive version involving anxiety or irritability, sometimes referred to as hypomania, have bipolar II (Kalat, 2013). Causes of the illness are not always clear, but one or a combination of factors such as neurochemical factors, environmental factors, and genetics usually play a part in the development of bipolar disorder (Bressert, 2007). Genetics are an essential factor, as bipolar disorder is a very biologically based illness. Certain genes have been shown to increase the risk of developing bipolar II disorder, and also some genes associated with a predisposition to major depression predispose to bipolar disorder. However, no definitive relationships exist between these genes and bipolar disorder (Kalat, 2013). Various statistics have been obtained through research as far as chances of developing bipolar disorder based on its prevalence within a family. For example, the risk of the illness is between fifteen and twenty-five percent for those with a parent who has bipolar disorder. Furthermore, the risk for someone whose non-identical twin has the condition is twenty-five percent, which increases eightfold if they are identical twins (Bressert, 2007). Biological Causes Overview Here is an overview of many different factors that are biological in nature and have implications in bipolar disorder, some of which will be explored in further detail later. As a primarily biological illness, the improper functioning of neurotransmitters such as serotonin, norepinephrine, and likely many others has been identified as a cause (Bressert, 2007). Another interesting biological factor includes the brain’s increased use of glucose throughout a manic episode and its decreased use of glucose during depressive episodes (Kalat, 2013). Studies analyzing the reelin gene which helps in brain function and development have found that there is a link between the dysfunction of the reelin gene and psychiatric disorders, specifically schizophrenia, and more importantly for this paper, bipolar disorder (Ovadia, 2011). On a side note, there have also been studies which have found a gene that may provide some sort of protection against bipolar disorder. It is called GRIK4, and as a ‘kainate-type ionotropic glutamate receptor’ is part of the glutamate neurotransmission process (Pickard, 2006). Another in teresting indicator of bipolar disorder was found using sensory gating, and involves the P85 gating ratio (Patterson, 2009). Relating to the circadian rhythm aspect of the disorder and how disruption of this due to the disorder can be a cause of the manic and depressive states in bipolar patients, there have been some studies. The results of one study found an association between the NR1D1 and GSK3ÃŽÂ ² variants and differences in functioning of the expression of genes related to the ‘circadian clock’ system (McCarthy, 2011). An association specific to rapid cycling bipolar disorder involves the gene variation of CRY2, a ‘clock gene’ (Sjà ¶holm, 2010). A biological marker related to gluten sensitivity has been discovered which showed that those with bipolar disorder have ‘increased levels of IgG antibodies to gliadin’ (Dickerson, 2011). Finally, a recent study looked into gene expression in  lymphoblastoid cells, which could be a possible biological marker of bipolar disorder (Kato, 2011). Overall, it seems that there are still many questions as far as biological causes of the disorder, though progress towards the specifics of those markers is definitely being made.