@article{vandeKerkhofFekkesvanderHeijdenetal.2016,
  author    = {van de Kerkhof, Nora WA and Fekkes, Durk and van der Heijden, Frank MMA and Hoogendijk, Witte JG and St{\"o}ber, Gerald and Egger, Jos IM and Verhoeven, Willem MA},
  title     = {Cycloid psychoses in the psychosis spectrum: evidence for biochemical differences with schizophrenia},
  series = {Neuropsychiatric Disease and Treatment},
  volume    = {12},
  journal   = {Neuropsychiatric Disease and Treatment},
  doi       = {10.2147/NDT.S101317},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166255},
  pages     = {1927-1933},
  year      = {2016},
  abstract  = {Cycloid psychoses (CP) differ from schizophrenia regarding symptom profile, course, and prognosis and over many decades they were thought to be a separate entity within the psychosis spectrum. As to schizophrenia, research into the pathophysiology has focused on dopamine, brain-derived neurotrophic factor, and glutamate signaling in which, concerning the latter, the N-methyl-d-aspartate receptor plays a crucial role. The present study aims to determine whether CP can biochemically be delineated from schizophrenia. Eighty patients referred for psychotic disorders were assessed with the Comprehensive Assessment of Symptoms and History, and (both at inclusion and after 6 weeks of antipsychotic treatment) with the Positive and Negative Syndrome Scale and Clinical Global Impression. From 58 completers, 33 patients were diagnosed with schizophrenia and ten with CP according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and Leonhard criteria, respectively. Fifteen patients were diagnosed with other disorders within the psychosis spectrum. At both time points, blood levels of the dopamine metabolite homovanillic acid, brain-derived neurotrophic factor, and amino acids related to glutamate neurotransmission were measured and compared with a matched control sample. Patients with CP showed a significantly better response to antipsychotic treatment as compared to patients with schizophrenia. In CP, glycine levels were elevated and tryptophan levels were lowered as compared to schizophrenia. Glutamate levels were increased in both patient groups as compared to controls. These results, showing marked differences in both treatment outcome and glutamate-related variable parameters, may point at better neuroplasticity in CP, necessitating demarcation of this subgroup within the psychosis spectrum.},
  language  = {en}
}
@article{IslesIngasonLowtheretal.2016,
  author    = {Isles, Anthony R. and Ingason, Andr{\´e}s and Lowther, Chelsea and Walters, James and Gawlick, Micha and St{\"o}ber, Gerald and Rees, Elliott and Martin, Joanna and Little, Rosie B. and Potter, Harry and Georgieva, Lyudmila and Pizzo, Lucilla and Ozaki, Norio and Aleksic, Branko and Kushima, Itaru and Ikeda, Masashi and Iwata, Nakao and Levinson, Douglas F. and Gejman, Pablo V. and Shi, Jianxin and Sanders, Alan R. and Duan, Jubao and Willis, Joseph and Sisodiya, Sanjay and Costain, Gregory and Werge, Thomas M. and Degenhardt, Franziska and Giegling, Ina and Rujescu, Dan and Hreidarsson, Stefan J. and Saemundsen, Evald and Ahn, Joo Wook and Ogilvie, Caroline and Girirajan, Santhosh D. and Stefansson, Hreinn and Stefansson, Kari and O'Donovan, Michael C. and Owen, Michael J. and Bassett, Anne and Kirov, George},
  title     = {Parental Origin of Interstitial Duplications at 15q11.2-q13.3 in Schizophrenia and Neurodevelopmental Disorders},
  series = {PLoS Genetics},
  volume    = {12},
  journal   = {PLoS Genetics},
  number    = {5},
  doi       = {10.1371/journal.pgen.1005993},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166706},
  pages     = {e1005993},
  year      = {2016},
  abstract  = {Duplications at 15q11.2-q13.3 overlapping the Prader-Willi/Angelman syndrome (PWS/AS) region have been associated with developmental delay (DD), autism spectrum disorder (ASD) and schizophrenia (SZ). Due to presence of imprinted genes within the region, the parental origin of these duplications may be key to the pathogenicity. Duplications of maternal origin are associated with disease, whereas the pathogenicity of paternal ones is unclear. To clarify the role of maternal and paternal duplications, we conducted the largest and most detailed study to date of parental origin of 15q11.2-q13.3 interstitial duplications in DD, ASD and SZ cohorts. We show, for the first time, that paternal duplications lead to an increased risk of developing DD/ASD/multiple congenital anomalies (MCA), but do not appear to increase risk for SZ. The importance of the epigenetic status of 15q11.2-q13.3 duplications was further underlined by analysis of a number of families, in which the duplication was paternally derived in the mother, who was unaffected, whereas her offspring, who inherited a maternally derived duplication, suffered from psychotic illness. Interestingly, the most consistent clinical characteristics of SZ patients with 15q11.2-q13.3 duplications were learning or developmental problems, found in 76\% of carriers. Despite their lower pathogenicity, paternal duplications are less frequent in the general population with a general population prevalence of 0.0033\% compared to 0.0069\% for maternal duplications. This may be due to lower fecundity of male carriers and differential survival of embryos, something echoed in the findings that both types of duplications are de novo in just over 50\% of cases. Isodicentric chromosome 15 (idic15) or interstitial triplications were not observed in SZ patients or in controls. Overall, this study refines the distinct roles of maternal and paternal interstitial duplications at 15q11.2-q13.3, underlining the critical importance of maternally expressed imprinted genes in the contribution of Copy Number Variants (CNVs) at this interval to the incidence of psychotic illness. This work will have tangible benefits for patients with 15q11.2-q13.3 duplications by aiding genetic counseling.},
  language  = {en}
}