Bibiana Cabrera

Criterios de valoración clínicos y de funcionamiento en un estudio de interacción gen-ambiente en primeros episodios psicóticos (PEPs)

The PEPs study is a multicenter, naturalistic, prospective, longitudinal study designed to evaluate clinical, neuropsychological, neuroimaging, biochemical, environmental and pharmacogenetic variables in a sample of nearly 350 first episode of psychosis patients and 250 healthy controls. The PEPs project was conducted in Spain from January 2009 to December 2011. This article describes the rationale for the measurement approach adopted, providing an overview of the selected clinical and functional measures. The main objectives are: a) the thorough clinical and neurocognitive characterization of a sample of first episodes of psychosis, and b) the study of the interactions between the genetic and environmental variables selected to predict clinical and brain structural outcomes, and to determine the relationship of genetic polymorphisms involved in the pharmacokinetics and pharmacodynamics, and the responses and adverse effects of treatment.

The impact of cognitive reserve in the outcome of first-episode psychoses: 2-year follow-up study

The concept of cognitive reserve (CR) suggests that the premorbid intelligence quotient (IQ), years of education and leisure activities provide more efficient cognitive networks and therefore allow a better management of some conditions associated to cognitive impairment. Fifty-two DSM-IV diagnosed FEP subjects were matched with 41 healthy controls by age, gender and parental socio-economic status. All subjects were assessed clinically, neuropsychologically and functionally at baseline and after a two-year follow-up. To assess CR at baseline, three proxies have been integrated: premorbid IQ, years of education-occupation and leisure activities. Higher CR was associated with better cognitive, functional and clinical outcomes at baseline. The CR proxy was able to predict working memory, attention, executive functioning, verbal memory and global composite cognitive score accounting for 48.9%, 19.1%, 16.9%, 10.8% and 14.9% respectively of the variance at two-year follow-up. CR was also significantly predictive of PANSS negative scale score (12.5%), FAST global score (13.4%) and GAF (13%) at two-year follow-up. In addition, CR behaved as a mediator of working memory (B=4.123) and executive function (B=3.298) at baseline and of working memory (B=5.034) at 2-year follow-up. An additional analysis was performed, in order to test whether this mediation could be attributed mainly to the premorbid IQ. We obtained that this measure was not enough by itself to explain this mediation. CR may contribute to neuropsychological and functional outcome. Specific programs addressed to improve cognition and functioning conducted at the early stages of the illness may be helpful in order to prevent cognitive and functional decline.

Cognition and psychopathology in first-episode psychosis: are they related to inflammation?

BACKGROUND Cognitive deficits are present from the onset of psychosis and are considered a core feature of the disorder. Increasing evidence suggests that cognitive function is associated with inflammatory processes. This study evaluated the association between cognition and inflammatory biomarkers in first-episode psychosis (FEP), in order to identify cognitive phenotypes from inflammatory expression profiles. METHOD A case-control study of 92 FEP patients and 80 matched controls was used. Neurocognitive assessment, including verbal ability, sustained attention, verbal memory, working memory and executive function, was performed. The expression of pro- and anti-inflammatory mediators of the main intracellular inflammatory pathway was measured in peripheral blood mononuclear cells and plasma. RESULTS FEP patients performed worse in all cognitive domains compared to controls and had higher expression of pro-inflammatory mediators and lower expression of anti-inflammatory mediators. In the FEP group, cognition and psychopathology were associated with inflammation. Hierarchical regression analysis showed that association between the anti-inflammatory prostaglandin 15d-PGJ2 and sustained attention on one hand, and COX-2 expression and executive function on the other, were statistically significant. CONCLUSIONS Our study provides evidence for an association between anti-inflammatory biomarkers and cognition in FEP. The identification of a subgroup of patients based on these measures could be useful to guide treatment programmes by providing tools to select a personalized treatment approach, but longitudinal studies are needed before. In the future, establishment of biomarkers linked to cognition would be useful to monitor the course of cognitive impairment, but substantially more data will be required. Determination of IκBα, the inhibitory protein of the pro-inflammatory transcription factor NFκB, could be useful in early phases to assess clinical severity.

The course of negative symptoms in first-episode schizophrenia and its predictors: A prospective two-year follow-up study

AIMS This study aimed to investigate the course of negative symptoms and its stability over a two-year period following a first-episode schizophrenia (FES) and the possible predictors of higher severity in this symptomatology after this period. METHODS In this longitudinal two-year prospective follow-up study we included 268 patients with a FES, according to DSM-IV. Analysis of variance was conducted in patients who completed the full follow-up to study changes in negative symptoms over three visits. Regression analyses were conducted to show correlates and potential predictors of negative symptoms at two-year follow-up. RESULTS There was a significant effect for time in negative symptomatology, which was less severe at one-year follow-up after a FES and remained stable up to two years (Time 1>Time 2>Time 3); F(2,151)=20.45, p<0.001. Poorer premorbid adjustment (p=0.01) and higher negative symptoms at baseline (p<0.001) made a significant contribution to the changes in the negative symptoms severity at two-years after a FES (R2=0.21, p<0.001). CONCLUSIONS We found a reduction in the negative symptomatology at one-year after a FES. This change remained stable at two-year. Our results suggested that the presence of this symptomatology early in the course of the illness, together with a poorer premorbid adjustment, predict more severe negative symptoms at mid-term outcome.

Modelling gene-environment interaction in first episodes of psychosis

INTRODUCTION Recent research demonstrates the heterogeneous etiology of psychotic disorders, where gen-environment (GxE) interaction plays a key role. Large genetic studies have linked many genetic variants with schizophrenia, but each variant is only associated with a small effect and the GxE interaction contribution has not been evaluated. METHODS The PEPs Project was designed to carefully collect a large amount of genetic and environmental exposure data of 335 FEP patients and 253 matched healthy controls.780single-nucleotide polymorphisms (from 159 candidate genes)and 16 environmental variables previously reported as the main psychosis non-genetic risk factors were analyzed together using entropy-based measures of information gain. RESULTS Our analyses identified an interaction between nine SNPs and the exposition to the environmental risk factors of psychosis, showing a clear enrichment of genes linked to serotonin neurotransmission and neurodevelopmental processes. CONCLUSIONS This study has allowed the identification of several GxE-environment interactions involved in the risk of presenting a FEP. Our results highlight the importance of serotonin neurotransmission interacting with certain environmental stimuli. The serotoninergic system may be playing a key role in the regulatory network of stress and other systems implicated in the emergence and development of psychotic disorders.

Cannabis use, COMT, BDNF and age at first-episode psychosis

Although an interaction between COMT Val158Met and BDNF Val66Met polymorphisms with cannabis use has been proposed with respect to the risk of psychosis emergence, findings remain inconclusive. The aim of the present study was to evaluate the different possible associations between these polymorphisms and early cannabis use and the age at the first episode of psychosis. The relationship between age at psychosis onset and COMT Val158Met and BDNF Val66Met polymorphisms with early cannabis use as well as those factors associated with early cannabis use were investigated. Among 260 Caucasian first-episode psychosis patients, early cannabis use and the presence of the met-allele from the BDNF Val66Met polymorphism were significantly associated with age at psychosis onset. Furthermore, early cannabis use was significantly associated with male gender in the logistic regression analysis. These findings provide evidence of the important role of early cannabis use and the Val66Met BDNF polymorphism on age at psychosis onset and they point out to sex-specific differences in cannabis use patterns.

Metabolic syndrome or glucose challenge in first episode of psychosis

Patients with schizophrenia exhibit a reduced life expectancy. Although unhealthy lifestyle or suicide risk plays a role, the main causes are diverse medical conditions such as cardiovascular diseases, type 2 diabetes mellitus and metabolic syndrome. Albeit pharmacological secondary side effects might also trigger previous conditions, studies in naïve patients reflect diverse anomalies at the onset. Patients with a first episode of psychosis, display a wide scope of metabolic abnormalities, ranging from normality till pathological values depending on the parameters studied. We attempted to evaluate the metabolic syndrome and glycemic homeostasis in a subset of antipsychotic-naïve patients with a first episode of non-affective psychosis. Patients (n=84) showed a similar prevalence of metabolic syndrome compared with a matched control sample (n=98) (6% vs 4%, P=0.562), while glucose homeostasis values differed significantly (14% vs. 5%, P=0.034). Our results suggest that metabolic syndrome is not a useful clinical condition to be evaluated in patients before pharmacological treatment. Abnormal glycemic homeostasis at the onset of the disease requires specific diagnostic tools and preventive measures in order to avoid future cardiovascular events. New strategies must be implemented in order to evaluate the cardiovascular risk and subsequent morbidity in patients at the onset of the disease.

A Pharmacovigilance Study in First Episode of Psychosis: Psychopharmacological Interventions and Safety Profiles in the PEPs Project

Background: The characterization of the first episode of psychosis and how it should be treated are principal issues in actual research. Realistic, naturalistic studies are necessary to represent the entire population of first episode of psychosis attended in daily practice. Methods: Sixteen participating centers from the PEPs project recruited 335 first episode of psychosis patients, aged 7 to 35 years. This article describes and discusses the psychopharmacological interventions and safety profiles at baseline and during a 60-day pharmacovigilance period. Results: The majority of first episode of psychosis patients received a second-generation antipsychotic (96.3%), orally (95%), and in adjusted doses according to the product specifications (87.2%). A total of 24% were receiving an antipsychotic polytherapy pattern at baseline, frequently associated with lower or higher doses of antipsychotics than the recommended ones. Eight patients were taking clozapine, all in monotherapy. Males received higher doses of antipsychotic (P=.043). A total of 5.2% of the patients were being treated with long-acting injectable antipsychotics; 12.2% of the patients received anticholinergic drugs, 12.2% antidepressants, and 13.7% mood stabilizers, while almost 40% received benzodiazepines; and 35.52% reported at least one adverse drug reaction during the pharmacovigilance period, more frequently associated with higher antipsychotic doses and antipsychotic polytherapy (85.2% vs 45.5%, P<.001). Conclusions: These data indicate that the overall pharmacologic prescription for treating a first episode of psychosis in Spain follows the clinical practice guideline recommendations, and, together with security issues, support future research of determinate pharmacological strategies for the treatment of early phases of psychosis, such as the role of clozapine, long-acting injectable antipsychotics, antipsychotic combination, and the use of benzodiazepines.

Opposite cannabis-cognition associations in psychotic patients depending on family history

The objective of this study is to investigate cognitive performance in a first-episode psychosis sample, when stratifying the interaction by cannabis use and familial or non-familial psychosis. Hierarchical-regression models were used to analyse this association in a sample of 268 first-episode psychosis patients and 237 controls. We found that cannabis use was associated with worse working memory, regardless of family history. However, cannabis use was clearly associated with worse cognitive performance in patients with no family history of psychosis, in cognitive domains including verbal memory, executive function and global cognitive index, whereas cannabis users with a family history of psychosis performed better in these domains. The main finding of the study is that there is an interaction between cannabis use and a family history of psychosis in the areas of verbal memory, executive function and global cognition: that is, cannabis use is associated with a better performance in patients with a family history of psychosis and a worse performance in those with no family history of psychosis. In order to confirm this hypothesis, future research should explore the actual expression of the endocannabinoid system in patients with and without a family history of psychosis.

Pharmacogenetic study of antipsychotic induced acute extrapyramidal symptoms in a first episode psychosis cohort: role of dopamine, serotonin and glutamate candidate genes

This study investigated whether the risk of presenting antipsychotic (AP)-induced extrapyramidal symptoms (EPS) could be related to single-nucleotide polymorphisms (SNPs) in a naturalistic cohort of first episode psychosis (FEP) patients. Two hundred and two SNPs in 31 candidate genes (involved in dopamine, serotonin and glutamate pathways) were analyzed in the present study. One hundred and thirteen FEP patients (43 presenting EPS and 70 non-presenting EPS) treated with high-potency AP (amisulpride, paliperidone, risperidone and ziprasidone) were included in the analysis. The statistical analysis was adjusted by age, gender, AP dosage, AP combinations and concomitant treatments as covariates. Four SNPs in different genes (DRD2, SLC18A2, HTR2A and GRIK3) contributed significantly to the risk of EPS after correction for multiple testing (P<1 × 10−4). These findings support the involvement of dopamine, serotonin and glutamate pathways in AP-induced EPS.