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Background: Affective syndrome is thought to be a key feature that differentiates schizophrenia from schizoaffective disorder (SA) and bipolar disorder with psychotic features (BDP). However genetic underpinnings of these differences remain unresolved.Objectives: We compared clinical variables of affective psychoses (SA, BDP and schizophrenia with affective symptoms (AFF SCZ)) and schizophrenia without affective symptoms (non-AFF SCZ) and searched for a genetic variant that may differentiate affective psychosis from non-AFF SCZ.Methods: A total of 2677 subjects, including 831 patients with affective psychosis, 785 patients with non-AFF SCZ and 1061 healthy controls, were used. Clinical symptoms were assessed with the PANSS. The sample was genotyped for 5-HTTLPR polymorphism of the serotonin transporter gene.Results: The diagnostic groups differed significantly on demographic and clinical variables. The percentage of men was higher, the current age and age at illness onset were lower in non-AFF SCZ and SA compared to AFF SCZ and BDP. The severity of positive and negative symptoms decreased significantly from group to group in the following manner: non-AFF SCZ>AFF SCZ>SA>BDP. There was the association between 5-HTTLPR polymorphism and affective psychosis (p=0.01). The frequency of the SS genotype was higher in the affective psychosis group compared to non-AFF SCZ and controls. No differences in the genotype distribution were identified between the non-AFF SCZ group and controls.Limitations: Difficulties in the differentiation between non-AFF SCZ and AFF SCZ or SA and between AFF SCZ and SA due to uncertain diagnostic boundaries between these conditions.Conclusions: SA is intermediate between non-AFF SCZ and BDP in the severity of positive and negative symptoms. The first episode patients, carriers of the SS genotype have a higher risk of developing affective psychosis than non-AFF SCZ. This finding carries implications for the prognosis of psychosis outcomes in the first-episode patients. [ABSTRACT FROM AUTHOR]

Abstract: Serotonin type 2A receptors (5-HTR2A) have long been implicated in schizophrenia pathology. A decreased number of these receptors were found in postmortem brain studies of schizophrenic patients as well as in experiments using neuroimaging techniques. Molecular genetic studies revealed that the T102C polymorphism of the 5-HTR2A gene is associated with schizophrenia, with the CC genotype frequency being higher in patients compared to healthy controls. However the association was not confirmed in all studies. We carried out a replication study, which aimed at searching for association between this polymorphism and schizophrenia in a large samples of patients (n =919), their psychiatrically well first-degree relatives (n =330) and screened controls (n =500). The C allele and the CT+CC genotype frequencies were significantly higher in patients than in controls (χ2 =5.1; df=1; p =0.02; OR 1.2, 95% CI 1.0–1.4) and χ2 =5.4; df=1; p =0.02; OR 1.4, 95% CI 1.1–1.8 respectively). In a family-based study, the transmission disequilibrium test (TDT) and the family-based association test (FBAT) did not show a preferential transmission of any allele. In conclusion, our replication study provides further evidence for association between the 5-HTR2A receptor T102C polymorphism and schizophrenia. [Copyright &y& Elsevier]

Serotonin receptor (5HTR2A) gene polymorphism has been reported to be associated with clinical phenotypes in schizophrenia. The current study attempted to investigate a relationship between 5HTR2A 102T/C polymorphism and personality traits as well as clinical symptoms in patients with ICD-10 diagnoses of schizophrenia and affective disorders. 5HTR2A genotyping, clinical and psychological assessment were administered to 375 patients, 104 first-degree healthy relatives of the patients and 157 controls. In the patients an association was observed between the 2/2 5HTR2A genotype and scores on the Hypochondriasis scale (MMPI) (ANOVA, F = 4.56; P = 0.011) and trait anxiety (F = 4.21; P = 0.002). A significant difference between 1/1 and 2/2 genotypes has been also found for Neuroticism scores (EPI) (t = 2.18; P = 0.0031). No significant differences by 5HTR2A genotype were observed in either the control or first-degree relativesˈ group for all scales studied. Positive, negative and psychopathological symptoms emerged higher in the 2/2 genotype patients compared to other genotype carriers. Therefore, the 2/2 genotype may contribute to produce the phenotype, with specific clinical and pathological features in common, regardless of nosologic heterogeneity of psychoses. [Copyright &y& Elsevier]