Different Genes Impact on Bipolar II Disorder with and without Comorbid Anxiety Disorder

• Main Authors: Yu-ShanWang, 王于珊
• Other Authors: Ru-Band Lu
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/83596357915338584949

碩士 === 國立成功大學 === 行為醫學研究所 === 100 === Aim: The aim of this study was to clarify aldehyde dehydrogenase 2 (ALDH2) and dopamine D2 receptor (DRD2) genes for predisposition to Bipolar II disorder (BP-II) comorbid with and without anxiety disorders (AD). To specify phenotype of BP-II and to reduce heterogeneity in the etiology of BP-II might support that comorbid AD is a subtype of BP-II. Background: The presence of comorbidity compounds disability, complicates treatment, and appears to worse the prognosis of bipolar disorders (BP). The frequently comorbid conditions include substance use disorders and anxiety disorders (AD) (generalized anxiety disorder, social phobia, panic disorder, obsessive compulsive disorder, and post-traumatic stress disorder), but comorbid AD has been underrecognized and understudies. The dopaminergic system has been implicated in the pathogenesis of BP and AD. The genes involved in metabolizing dopamine and encoding dopamine receptors, such as the aldehyde dehydrogenase 2 (ALDH2) and dopamine D2 receptor (DRD2) genes may be important. In the past few decades, a number of studies have investigated the association of DRD2 gene with BP as well as AD, but the findings are controversial. However, the comorbidity rate of AD and BP was relatively lower in the Han Chinese population than in the Western population. It may be easier for us to clarify the association of the DRD2 and ALDH2 polymorphisms and the possible interactions in BP-II with and without AD. Method: The sample consisted of total 462 BP-II patients with Research Diagnostic Criteria for 2-day hypomania cutoff based on DSM-IV-TR. 335 subjects were BP-II without AD, 127 subjects were of BP-II with AD and 348 were healthy subjects as normal control. The diagnosis for each patient was made by an attending psychiatrist and confirmed by a clinical psychologist using the Chinese Version of the Modified Schedule of Affective Disorder and Schizophrenia-Lifetime (SADS-L) to screen their psychiatric conditions. The genotypes of the ALDH2 and DRD2 TaqIA polymorphisms were determined using polymerase chain reactions plus restriction fragment length polymorphism analysis. Results: Logistic regression analysis showed a statistically significant association between DRD2 Taq-I A1/A2 genotype and BP-II with AD (OR=2.231, P=0.021). Moreover, a significant interaction of the DRD2 Taq-I A1/A1 and the ALDH2*1*1 genotypes in BP-II without AD was revealed. (OR=5.623, P= 0.001) to compare with normal control. Conclusion: Our findings support the hypothesis that a unique genetic distinction between BP-II with and without AD, and suggest a novel association between DRD2 Taq-I A1/A2 genotype and BP-II with AD. Our study also provides further evidence that the ALDH2 and DRD2 genes interact in BP-II, particularly BP-II without AD.