Neuroimaging studies have so far failed to demonstrate a consistent pattern of abnormalities, though receptor occupancy studies show an exaggerated response to dopamine receptor activation through dysfunctional secondary messenger systems. The presentation of psychosis in bipolar disorder suggests there may be region-specific increases in dopaminergic neurotransmission, though not necessarily a global increase in dopamine signalling. There is some evidence that increased dopamine activity in the brain may be important in the aetiology of mania, particularly since many drugs that increase dopaminergic signalling in the central nervous system can be associated with symptoms characteristic of mania such as elevated mood, reduced need for sleep and reduction in social inhibitions. The literature suggests that this may be mediated by circadian rhythm disruptions in genetically predisposed individuals. Negative life events can precipitate depressive or manic episodes in people with bipolar disorder. ![]() Instead, they are associated with the risk of psychiatric disorders in general. The majority of environmental factors which contribute to the aetiology of bipolar disorder are not specific to this condition. 3 Genetic contributions may also be associated with copy number variants and gene-gene interactions. Some polymorphisms in genes that code for monoamine transporters and brain-derived neurotrophic factor (BDNF) are associated with an increased risk of bipolar disorder.Įvidence suggests there is an overlap in the genetic risk between bipolar disorder and schizophrenia. The genetic risk associated with bipolar disorder is a type of polygenic inheritance (the sum effect of many low-penetrance mutations). Heritability is around 60% in monozygotic twins and around 20% in dizygotic twins. 1 Genetic factorsįirst-degree relatives of a person affected with bipolar disorder are at increased risk of developing bipolar and unipolar mood disorders and schizoaffective disorder. Though bipolar disorder is heritable within families, having an affected first-degree relative does not guarantee a person will be affected with the disorder, and therefore genetics alone does not explain the entire aetiology. ![]() The aetiology of bipolar disorder is complex and involves genetic, environmental, and neurobiological components. You might also be interested in our premium collection of 1,000+ ready-made OSCE Stations, including a range of psychiatry stations ✨ Aetiology
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |