Bipolar Disorder, Schizoaffective Disorder, and Schizophrenia Overlap: A New Comorbidity Index
ABSTRACT Growing evidence of an etiologic overlap between schizophrenia, schizoaffective disorder, and bipolar disorder has become increasingly difficult to disregard. We investigated the magnitude of the overlap between the clinical diagnoses of bipolar affective disorder, schizoaffective disorder, and schizophrenia over a 35-year period based on the entire Danish population.
We established a register-based prospective cohort study of more than 2.5 million persons born in Denmark after 1954. Risks for the 3 psychiatric disorders were estimated by survival analysis using the Aalen-Johansen method. Cohort members were followed from 1970 to 2006. We introduced a new comorbidity index measuring the magnitude of the overlap between the 3 disorders.
Overall, 12,734 patients were admitted with schizophrenia, 4,205 with bipolar disorder, and 1,881 with schizoaffective disorder. A female bipolar patient's risk of also being admitted with a schizoaffective disorder by the age of 45 years was approximately 103 times higher than that of a woman at the same age in the general population. Thus, we defined the comorbidity index between schizoaffective disorder and bipolar disorder at age 45 years to be 103. At age 45 years, the index between schizophrenia and schizoaffective disorder was 80 and between schizophrenia and bipolar disorder was 20. Similar large comorbidity indexes were found for men.
A large comorbidity index between schizophrenia and schizoaffective disorder was found, as well as a large index between bipolar disorder and schizoaffective disorder. But, more surprisingly, it was clear that a substantial comorbidity index between bipolar disorder and schizophrenia was present. This study supports the existence of an overlap between bipolar disorder and schizophrenia and thus challenges the strict categorical approach used in both DSM-IV and ICD-10 classification systems.
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ABSTRACT: Background. Persons with severe mental illness (SMI) have excess mortality, which may partly be explained by their high prevalence of diabetes. Method. We compared the overall and cause-specific mortality in persons with SMI and diabetes with that of the general Danish population between 1997 and 2009 by linking data from Danish national registries. Results. The cohort counted 4734703 persons, and during follow-up 651080 persons died of whom 1083 persons had SMI and diabetes. Compared with the background population, the overall mortality rate ratios (MRRs) for persons with SMI and diabetes were 4.14 [95% confidence interval (CI) 3.81-4.51] for men and 3.13 (95% CI 2.88-3.40) for women. The cause-specific MRRs for persons with SMI and diabetes were lowest for malignant neoplasms (women: MRR=1.98, 95% CI 1.64-2.39; men: MRR=2.08, 95% CI 1.69-2.56) and highest for unnatural causes of death (women: MRR=12.31, 95% CI 6.80-22.28; men: MRR=7.89, 95% CI 5.51-11.29). The cumulative risks of death within 7 years of diabetes diagnosis for persons with SMI and diabetes were 15.0% (95% CI 12.4-17.6%) for those younger than 50 years, 30.7% (95% CI 27.8-33.4%) for those aged 50-69 years, and 63.8% (95% CI 58.9-68.2%) for those aged 70 years or older. Among persons suffering from both diseases, 33.4% of natural deaths were attributed to diabetes and 14% of natural deaths were attributed to the interaction between diabetes and SMI. Conclusions. Long-term mortality is high for persons with SMI and diabetes. This calls for effective intervention from a coordinated and collaborating healthcare system.Psychological Medicine 03/2014; 44(14):1-11. DOI:10.1017/S0033291714000634 · 5.43 Impact Factor
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ABSTRACT: Clathrin-mediated endocytosis is one of several mechanisms for retrieving transmembrane proteins from the cell surface. This key mechanism is highly conserved in evolution and is found in any eukaryotic cell from yeast to mammals. Studies from several model organisms have revealed that filamentous actin (F-actin) plays multiple distinct roles in shaping Clathrin-mediated endocytosis. Yet, despite the identification of numerous molecules at the interface between endocytic machinery and the cytoskeleton, our mechanistic understanding of how F-actin regulates endocytosis remains limited. Key insights come from neurons where vesicular release and internalization are critical to pre- and postsynaptic function. Recent evidence from human genetics puts postsynaptic organization, glutamate receptor trafficking, and F-actin remodeling in the spotlight as candidate mechanisms underlying neuropsychiatric disorders. Here I review recent findings that connect the F-actin cytoskeleton mechanistically to Clathrin-mediated endocytosis in the central nervous system, and discuss their potential involvement in conferring risk for neuropsychiatric disorder.Communicative & integrative biology 04/2014; 7:e28740. DOI:10.4161/cib.28740
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ABSTRACT: Schizophrenia, schizoaffective and bipolar disorders share some common symptoms. However, the biomarkers underlying those disorders remain unclear. In fact, there is still controversy about the schizoaffective disorder with respect to its validity of independent category and its relationship with schizophrenia and bipolar disorders. In this paper, based on brain functional networks extracted from resting-state fMRI using a recently proposed group information guided ICA (GIG-ICA) method, we explore the biomarkers for discriminating healthy controls, schizophrenia patients, bipolar patients, and patients with two symptom defined subsets of schizoaffective disorder, and then investigate the relationship between different groups. The results demonstrate that the discriminating regions mainly including frontal, parietal, precuneus, cingulate, supplementary motor, cerebellar, insular and supramarginal cortices perform well in distinguishing the different diagnostic groups. The results also suggest that schizoaffective disorder may be an independent disorder, although its subtype characterized by depressive episodes shares more similarity with schizophrenia.