Is Bipolar Disorder Genetic?
Is Bipolar Disorder Genetic?
It become inevitable to examine genetically in terms of incidence, clinical characteristics, and familial incidence of the disease in children and adolescents. There are discussions on etiology. Genetic, environmental factors, neurobiological, hormonal and neurochemical factors are mentioned and researches are carried out.
Genetic Infrastructure of Bipolar Disorder (BD);
Even though the results revealed in the studies conducted are contradictory about the regions that can be held responsible in the genome, the common result of all the research is that genetic transfer in BD is not to be neglected. The high incidence of the disease in the children of adults with bipolar disorder and the parents and relatives of children with BD indicates the importance of genetic etiology.
In the studies conducted, the incidence of BDin children with the disease was found to be 7 times higher than that of healthy children. This risk is not just for BD. Individuals with depression, behavioral disorder, destructive behavioral disorder and anxiety disorders were found to have a higher incidence of BD in children than healthy ones. The incidence of the disease in children of individuals with BD is 5, 7%.
Besides familial genetic transfer studies, twin studies have been an important source of data about the genetic transmission of all diseases in medicine; It is one of the only resources we have in determining how effective genetic factors are compared to environmental factors. If we think that genetics plays an important role in the basis of a disease, it is anticipated that high concordant (co-illness) will be detected in monozygotic studies. Considering the BD, the concordantness of the disease in single twins is 70-90%, while in twin twins the rate is 16-35%.
Many scientific studies have started to reveal very important data about the BD formation process. For example, functional magnetic resonance (IMR) studies, a brain imaging method, showed reduced metabolic activity in some brain regions (especially in the dorsolateral prefrontal cortex) and increased in some regions (right cerebellar hemisphere) (DelBello et al., 2003). Structural magnetic resonance (MR) imaging studies also showed differences in some brain regions (especially subcortical white matter hyperintensity) in BD cases (Pillai et al., 2002).
Molecular Genetic Studies
Some differences in brain biochemistry have also been detected in patients with BD. Changes in levels of neurotransmitters such as dopa-min, noradrenaline, serotonin, and sometimes hormones such as thyroid hormones or melatonin have been found important in the formation of BD, especially in the brain. In addition, the role of secondary messenger systems in the nerve cell has come to the fore in the BD formation process.