The prevalence and clinical correlates of medical disorders comorbidities in patients with bipolar disorder.

OBJECTIVE: Medical disorders in patients with bipolar disorder (BD) have attracted more and more attention. So far, there is still a lack of studies on this issue utilizing large sample sizes in the Chinese sample. Therefore, we conducted this study to explore the clinical characteristics of BD patients comorbid medical disorders in a relatively large Chinese sample. METHODS: This was a cross-sectional study including 1,393 BD patients (882 patients with medical disorders and 511 patients without medical disorders). Their demographic and clinical characteristics were obtained by the Hospital Information System and self-designed questionnaires. RESULTS: The comorbidity rate of medical disorders in BD was 63.32%. The average number of medical disorders for a BD patient was 2.69. The top five comorbid medical disorders in BD patients were circulatory system diseases (19%), nervous system diseases (18%), endocrine and metabolic diseases (17%), digestive system diseases (16%), and respiratory system diseases (8%). BD patients with comorbid medical disorders had an older average age, lower education level, longer illness course, later onset age, lower ratio of psychotic features, more admission numbers, higher ratio of smoking and drinking alcohol, more number of manic episodes (All P < 0.05). Smoking, numbers of depressive episode, onset age, and illness course were independent risk factors of comorbidities in BD patients (All P < 0.05). CONCLUSIONS: Medical disorders in Chinese BD patients are highly prevalent. The smoking, number of depressive episodes, onset age, illness course, are correlated with BD patients comorbid medical disorders. Clinicians should pay attention to the medical disorders comorbidities in BD patients, and take effective measures to improve treatment outcome and reduce the suffering. The integrative approach should be the imperative in clinical practice.

GABRB2 Haplotype Association with Heroin Dependence in Chinese Population.

Substance dependence is a frequently observed comorbid disorder in schizophrenia, but little is known about genetic factors possibly shared between the two psychotic disorders. GABRB2, a schizophrenia candidate gene coding for GABAA receptor ß2 subunit, is examined for possible association with heroin dependence in Han Chinese population. Four single nucleotide polymorphisms (SNPs) in GABRB2, namely rs6556547 (S1), rs1816071 (S3), rs18016072 (S5), and rs187269 (S29), previously associated with schizophrenia, were examined for their association with heroin dependence. Two additional SNPs, rs10051667 (S31) and rs967771 (S32), previously associated with alcohol dependence and bipolar disorder respectively, were also analyzed. The six SNPs were genotyped by direct sequencing of PCR amplicons of target regions for 564 heroin dependent individuals and 498 controls of Han Chinese origin. Interestingly, it was found that recombination between the haplotypes of all-derived-allele (H1; OR = 1.00) and all-ancestral-allele (H2; OR = 0.74) at S5-S29 junction generated two recombinants H3 (OR = 8.51) and H4 (OR = 5.58), both conferring high susceptibility to heroin dependence. Additional recombination between H2 and H3 haplotypes at S1-S3 junction resulted in a risk-conferring haplotype H5 (OR = 1.94x109). In contrast, recombination between H1 and H2 haplotypes at S3-S5 junction rescued the risk-conferring effect of recombination at S5-S29 junction, giving rise to the protective haplotype H6 (OR = 0.68). Risk-conferring effects of S1-S3 and S5-S29 crossovers and protective effects of S3-S5 crossover were seen in both pure heroin dependent and multiple substance dependence subgroups. In conclusion, significant association was found with haplotypes of the S1-S29 segment in GABRB2 for heroin dependence in Han Chinese population. Local recombination was an important determining factor for switching haplotypes between risk-conferring and protective statuses. The present study provide evidence for the schizophrenia candidate gene GABRB2 to play a role in heroin dependence, but replication of these findings is required.