Korver-Nieberg N, Quee PJ, Boos HB, Simons CJ, Aust N Z J Psychiatry 2011 Dec;45(12):1061-8 PMID: 22026404 Abstract OBJECTIVE: The schizophrenia and other non-affective disorders categories listed in the DSM-IV, are currently under revision for the development of the fifth edition. The aim of the present study is to demonstrate the validity of these categories by investigating possible differences between …
Cognitive alterations in patients with non-affective psychotic disorder and their unaffected siblings and parents
Meijer J, Simons CJ, Quee PJ, Verweij K, Acta Psychiatr Scand 2012 Jan;125(1):66-76 PMID: 22013907 Abstract OBJECTIVE: The purpose of this study was to examine a range of cognitive measures as candidate phenotypic liability markers for psychosis in a uniquely large sample of patients with psychosis, their unaffected relatives and control subjects. METHOD: Patients with non-affective psychosis (n = 1093), …
Genome-wide association study identifies five new schizophrenia loci
Nat. Genet. 2011 Oct;43(10):969-76 PMID: 21926974 Abstract We examined the role of common genetic variation in schizophrenia in a genome-wide association study of substantial size: a stage 1 discovery sample of 21,856 individuals of European ancestry and a stage 2 replication sample of 29,839 independent subjects. The combined stage 1 and 2 analysis yielded genome-wide significant associations with schizophrenia for …
Cannabis and cognitive performance in psychosis: a cross-sectional study in patients with non-affective psychotic illness and their unaffected siblings
Meijer JH, Dekker N, Koeter MW, Quee PJ, van Beveren NJ, Meijer CJ, Psychol Med 2012 Apr;42(4):705-16 PMID: 21899795 Abstract BACKGROUND: The relationship between cannabis use and cognitive functioning in patients with psychosis has yielded contradictory findings. In individuals at genetic high risk for psychosis, information is sparse. The aim of this study was to assess the association between recency …
AKT1 moderation of cannabis-induced cognitive alterations in psychotic disorder
van Winkel R, van Beveren NJ, Simons C, Neuropsychopharmacology 2011 Nov;36(12):2529-37 PMID: 21775978 Abstract Genetic variation in AKT1 may be associated with sensitivity to the psychotomimetic effects of cannabis as well as with increased risk for psychotic disorder following cannabis use. Investigation of the effect of this interaction on relevant intermediate phenotypes for psychosis, such as cognition, may help to …
Differences in craving for cannabis between schizophrenia patients using risperidone, olanzapine or clozapine
Machielsen M, Beduin AS, Dekker N, , Kahn RS, Linszen DH, van Os J, Wiersma D, Bruggeman R, Cahn W, de Haan L, Krabbendam L, Myin-Germeys I J. Psychopharmacol. (Oxford) 2012 Jan;26(1):189-95 PMID: 21768161 Abstract Substance abuse and psychotic disorders have a high rate of comorbidity. Both disorders are associated with changes in the dopaminergic transmission in the mesocorticolimbic pathways …
Association of two DRD2 gene polymorphisms with acute and tardive antipsychotic-induced movement disorders in young Caucasian patients
Koning JP, Vehof J, Burger H, Wilffert B, Al Hadithy A, Alizadeh B, van Harten PN, Snieder H, Psychopharmacology (Berl.) 2012 Feb;219(3):727-36 PMID: 21750899 Abstract RATIONALE: Pharmacogenetic studies on antipsychotic-induced movement disorders (MD) in schizophrenia so far have focused mainly on tardive dyskinesia. Only a few examined the more acute antipsychotic-induced MD such as parkinsonism and akathisia. Notably, all MD …
Association between genetic variation in a region on chromosome 11 and schizophrenia in large samples from Europe
Rietschel M, Mattheisen M, Degenhardt F, , Mühleisen TW, Kirsch P, Esslinger C, Herms S, Demontis D, Steffens M, Strohmaier J, Haenisch B, Breuer R, Czerski PM, Giegling I, Strengman E, Schmael C, Mors O, Mortensen PB, Hougaard DM, Ørntoft T, Kapelski P, Priebe L, Basmanav FF, Forstner AJ, Hoffman P, Meier S, Nikitopoulos J, Moebus S, Alexander M, Mössner …
Social cognitive impairments and psychotic symptoms: what is the nature of their association?
Fett AK, Maat A, Schizophr Bull 2013 Jan;39(1):77-85 PMID: 21697150 Abstract Social cognitive deficits are associated with psychotic symptoms, but the nature of this association remains unknown. This study uses a genetically sensitive cross-trait cross-sibling design to investigate the nature of the overlap between both phenotypes. A sample of 1032 patients, 1017 of their healthy siblings, and 579 control subjects …
Genome-wide analysis shows increased frequency of copy number variation deletions in Dutch schizophrenia patients
Buizer-Voskamp JE, Muntjewerff JW, , Strengman E, Sabatti C, Stefansson H, Vorstman JA, Ophoff RA Biol. Psychiatry 2011 Oct;70(7):655-62 PMID: 21489405 Abstract BACKGROUND: Since 2008, multiple studies have reported on copy number variations (CNVs) in schizophrenia. However, many regions are unique events with minimal overlap between studies. This makes it difficult to gain a comprehensive overview of all CNVs involved …