05. Results Patients and controls were not different regarding demographic characteristics such as ethnicity and gender. Moreover, no differences were observed regarding genotype frequencies across these groups

(Table I). Table I. Genotype distribution and demographic characteristics across schizophrenic patients and healthy controls. *: χ2=0.14, P=0.93; †: χ2=1,45, P=023; ‡: χ2=0.86, P=0.77 We further analyzed the association Inhibitors,research,lifescience,medical between the genotype and allele frequencies of the T102C polymorphism and total and factor scores of the BPRS. As shown in Table II, no association was found. Table II. BPRS total scores and factor scores across genotypes in schizophrenic patients. BPRS, Brief Psychiatric Rating Scale. *: F=1.06, P=0.4; †: F=11.32, P=0.2; ‡: F=1.26, P=0.3; ║: F=0.5, P=0.88 The history of a suicide attempt and the suicide attempt characteristics were not associated with genotype,

allele frequencies, nor with psychopathological scores (Table III). Furthermore, Inhibitors,research,lifescience,medical the demographic characteristics were not statistically different between patients with a suicide attempt history (n=42; [32.5%], 23 were male, 19 were female; 28 were of Caucasian descent, 14 of African descent) and without such a history (n=87; [67.5%], Inhibitors,research,lifescience,medical 56 were male, 31 were female; 56 were of Caucasian descent, 31 were of African descent). In both groups the genotype frequencies were in Hardy-Weinberg equilibrium. Table III. Distribution of the 5-HT2A receptor gene 102 TC polymorphism in suicidal and nonsuicidal schizophrenic patients. BPRS, Brief Psychiatric Rating Scale. *: χ2=0.48, P=0.79; †: χ2=0.49, P=0.78; ‡: χ2=2.1, P=0.36; §: … Discussion Two previous meta-analyses had shown an association Inhibitors,research,lifescience,medical between the C allele of the T102C polymorphism and schizophrenia.3,14 However, these meta-analyses yielded relatively slight odds ratios (ORs)

of 1.18 and 1.1, respectively. An see more important question remains as to whether some characteristics present in schizophrenic patients, such as suicidality, rather than schizophrenia itself, Inhibitors,research,lifescience,medical could be related to the C allele. There is much evidence to support this hypothesis. until First, suicide is the leading cause of premature death in schizophrenic patients15,16 and a substantial percentage of patients with schizophrenic patients also attempt suicide, with estimates of lifetime occurrence ranging from 18% to 55 %.15 Second, a previous study showed an association between the C allele and suicidal thoughts in depressed patients,17 and we may speculate whether this same finding could be observed in schizophrenia. Third, it is also known that the 5-HT2A receptor is, at least indirectly, involved in suicidal behavior in both depressed and schizophrenic patients.6 Finally, it has been shown that the atypical antipsychotic clozapine, which acts on 5-HT2A, could have an antisuicidal action.