Cognitive Impairment and Affective Disorders in Patients With Obstructive Sleep Apnea Syndrome.

Sleep-related breathing disorders could be accompanied by or caused by a variety of medical conditions. They are considered to be a significant medical and social problem. Together with excessive daytime sleepiness, patients with obstructive sleep apnea experience neuropsychological symptoms such as anxiety, attention deficits, cognitive impairment, depressive symptoms and other psychological disturbances leading to social adjustment difficulties. Patients diagnosed with obstructive sleep apnea demonstrate a decline in a wide spectrum of cognitive abilities, including memory, attention, psychomotor speed, executive, verbal and visual-spatial skills. The aim of this study is to investigate the cognitive functioning and affective disorders among patients with obstructive sleep apnea syndrome and to examine the frequency and severity of cases in comparison with a control group consisting of healthy volunteers. Our research has shown that there is a relation between sleep apnea and cognitive impairments and affective changes. This relation can be explained by the direct effect of the syndrome on the patient, where the main connecting factor is the severity and the distribution of excessive daytime sleepiness. Along with treatment of the somatic medical condition, it is extremely important that the patient's mental state is treated as well. Trial Registration: 57/2013, Medical University - Sofia, Bulgaria.

Whole-genome-wide association study in the Bulgarian population reveals HHAT as schizophrenia susceptibility gene.

OBJECTIVE: Schizophrenia, the most common major psychiatric disorder (or group of disorders), entails severe decline of higher functions, principally with alterations in cognitive functioning and reality perception. Both genetic and environmental factors are involved in its pathogenesis; however, its genetic background still needs to be clarified. The objective of the study was to reveal genetic markers associated with schizophrenia in the Bulgarian population. METHODS: We have conducted a genome-wide association study using 554 496 single nucleotide polymorphisms (SNPs) in 188 affected and 376 unaffected Bulgarian individuals. Subsequently, the 100 candidate SNPs that revealed the smallest P-values were further evaluated in an additional set of 99 case and 328 control samples. RESULTS: We found a significant association between schizophrenia and the intronic SNP rs7527939 in the HHAT gene (P-value of 6.49×10 with an odds ratio of 2.63, 95% confidence interval of 1.89-3.66). We also genotyped additional SNPs within a 58-kb linkage disequilibrium block surrounding the landmark SNP. CONCLUSION: We suggest rs7527939 to be the strongest indicator of susceptibility to schizophrenia in the Bulgarian population within the HHAT locus.

Attitudes toward antipsychotic medication, insight and psychopathology in outpatients with schizophrenia.

OBJECTIVE: Attitude toward antipsychotic medication is considered as one of the main predictors for medication adherence in schizophrenia. The present non-interventional cross-sectional study aims to explore the associations between attitudes toward antipsychotic medication, insight and other clinical variables in outpatients with schizophrenia. METHOD: Attitudes toward antipsychotic medication, clinical and social variables, sociodemographic and illness-related characteristics were assessed via a set of semi-structured clinical interviews and self-rating scales in a total of 226 patients with schizophrenia on a long-term antipsychotic treatment in community based settings. The associations between attitudes toward medication and severity of psychopathology, insight and medication side effects were examined. RESULTS: The greater hospitalization rate in the previous year was associated with more severe psychopathology at the time of the study, more pronounced side effects of the therapy and lack of insight. The lack of insight, the presence of more severe negative and depressive symptoms and disease duration less than 5 years correlated significantly with negative attitudes toward antipsychotic medication. The severity of medication side effects was not associated with the drug attitudes. CONCLUSION: Psychoeducational and psychotherapeutical interventions, along with pharmacotherapy, can be beneficial in forming positive attitudes toward medication and improving medication adherence in schizophrenia, especially in patients with a short duration of the disease.

Obstructive sleep apnea syndrome and depressive symptoms.

A strong body of evidence has emerged over the recent years suggesting a relationship between obstructive sleep apnea (OSA) and depressive symptoms. The frequent co-occurrence of the two conditions makes it necessary that their co-morbidity and the pathogenetic relations between them should be studied in detail. Most of the studies to date have found a significant correlation between depressive symptoms and OSA. The basic pathogenetic mechanisms involved are disturbed neurotransmission, synaptic remodeling and neuronal death (neuroplasticity). Further longitudinal studies are needed to completely elucidate the OSA-depression relationship. Better knowledge of the problem may significantly improve diagnostics and therapeutical options in that group of patients.

Case-control association study of 59 candidate genes reveals the DRD2 SNP rs6277 (C957T) as the only susceptibility factor for schizophrenia in the Bulgarian population.

The development of molecular psychiatry in the last few decades identified a number of candidate genes that could be associated with schizophrenia. A great number of studies often result with controversial and non-conclusive outputs. However, it was determined that each of the implicated candidates would independently have a minor effect on the susceptibility to that disease. Herein we report results from our replication study for association using 255 Bulgarian patients with schizophrenia and schizoaffective disorder and 556 Bulgarian healthy controls. We have selected from the literatures 202 single nucleotide polymorphisms (SNPs) in 59 candidate genes, which previously were implicated in disease susceptibility, and we have genotyped them. Of the 183 SNPs successfully genotyped, only 1 SNP, rs6277 (C957T) in the DRD2 gene (P=0.0010, odds ratio=1.76), was considered to be significantly associated with schizophrenia after the replication study using independent sample sets. Our findings support one of the most widely considered hypotheses for schizophrenia etiology, the dopaminergic hypothesis.

Linkage analysis in bipolar pedigrees adds support for a susceptibility locus on 21q22.

Several studies provide suggestive evidence of a susceptibility locus for bipolar disorder at chromosome 21q22-23. In an attempt to replicate these findings, we have analyzed linkage to 11 polymorphic markers from this region in 18 Bulgarian pedigrees with affective disorder. Two-point linkage analysis under assumption of homogeneity and a dominant model with reduced penetrance produced modest positive values for some of the markers tested under a 'narrow' phenotype definition, including bipolar I and II, and schizoaffective disorder. The maximum two-point score (lod=1.76, theta=0.00) was at marker D21S1919. Non-parametric linkage analysis under the same phenotype model, yielded positive NPLall values (P<0.05) over the region between markers D21S211 and D21S416, with a peak at D21S1252 (NPL Zall=2.32, P=0.0003). The multipoint lod score (GENEHUNTER) reached a suggestive value for linkage (lod=2.10) also at marker D21S1252. The results under a recessive model were completely negative. These data add to the evidence for the existence of a susceptibility locus for bipolar affective disorder on chromosome 21q22.