The contribution of epidemiology to defining the most appropriate approach to genetic research on schizophrenia

Substance Use in Patients With First-Episode Psychosis: Is Gender Relevant?

OBJECTIVE

Only a few studies in patients with first-episode psychosis have included gender in the study hypothesis or considered this a primary study variable. The aim of this study was to explore the influence of gender in the pattern of substance use in patients with first-episode psychosis.

METHODS

This is a sub-analysis of a randomized open clinical trial that compared 1-year treatment retention rates of patients with first-episode psychosis randomized to haloperidol, olanzapine, quetiapine, risperidone, or ziprasidone. Our sub-analysis included 85 men and 29 women.

RESULTS

Substance use was relatively high among these patients and differed significantly by gender. Men were more likely to use substances overall than women (89.4% for men vs. 55.2% for women), χ(2) = 16.2, df = 1, p <.001, and were also more likely to use alcohol (χ(2) = 13, df = 1, p <.001), cannabis (χ(2) = 9.9; df = 1, p <.002), and cocaine (χ(2) = 10.3; df = 1, p <.001), compared to women. While there were no gender differences in age at first consumption of alcohol or cocaine, men were significantly younger at first consumption of cannabis (M = 16.08 years, SD = 2.1) than women (M = 18.0 years, SD = 3.8), F(1, 59) = 5, p <.02. When analyzed separately by gender, women showed no significant differences in the influence of number of substances used on age at onset of psychosis, F(3, 29) = 1.2, p =.30. However, there was a significant difference among men, with earlier onset of psychosis noted in men consuming multiple substances; F(4, 85) = 5.8, p <.0001. Regarding prediction of age at onset of psychosis, both male gender and the use of a higher number of substances significantly predicted an earlier age at onset of psychosis.

CONCLUSIONS

Our study provides some evidence of gender differences in the pattern of substance use in patients with first-episode psychosis, suggesting the possible need for gender-specific approaches in the interventions performed in these patients. This study is registered as #12610000954022 with the Australian New Zealand Clinical Trials Registry (www.anzctr.org.au).

Psychosis Incident Cohort Outcome Study (PICOS). A multisite study of clinical, social and biological characteristics, patterns of care and predictors of outcome in first-episode psychosis. Background, methodology and overview of the patient sample

AIMS

This paper aims at providing an overview of the background, design and initial findings of Psychosis Incident Cohort Outcome Study (PICOS).

METHODS

PICOS is a large multi-site population-based study on first-episode psychosis (FEP) patients attending public mental health services in the Veneto region (Italy) over a 3-year period. PICOS has a naturalistic longitudinal design and it includes three different modules addressing, respectively, clinical and social variables, genetics and brain imaging. Its primary aims are to characterize FEP patients in terms of clinical, psychological and social presentation, and to investigate the relative weight of clinical, environmental and biological factors (i.e. genetics and brain structure/functioning) in predicting the outcome of FEP.

RESULTS

An in-depth description of the research methodology is given first. Details on recruitment phase and baseline and follow-up evaluations are then provided. Initial findings relating to patients' baseline assessments are also presented. Future planned analyses are outlined.

CONCLUSIONS

Both strengths and limitations of PICOS are discussed in the light of issues not addressed in the current literature on FEP. This study aims at making a substantial contribution to research on FEP patients. It is hoped that the research strategies adopted in PICOS will enhance the convergence of methodologies in ongoing and future studies on FEP.

Is neuregulin 1 involved in determining cerebral volumes in schizophrenia? Preliminary results showing a decrease in superior temporal gyrus volume

BACKGROUND/AIMS

Reduced left superior temporal gyrus (STG) volume is one of the most replicated imaging findings in schizophrenia. However, it remains unclear whether genes play any role in our understanding of such structural alteration. It has been proposed that Neuregulin 1 (NRG1) might be a promising gene involved in schizophrenia, because of its role in neurodevelopment and neuroplasticity. In this study, the association between NRG1 and STG anatomy in patients with schizophrenia was explored for the first time.

METHODS

We investigated a 1-year treated prevalence cohort of patients with schizophrenia in contact with the South Verona Community-Based Mental Health Service. A blood sample was collected for DNA extraction and brain structure was assessed with an MRI scan. A total of 27 subjects with schizophrenia underwent both assessments and were included in the study.

RESULTS

We investigated the association between the polymorphism SNP8NRG222662 (rs4623364) of NRG1 and volume of the STG. We found that patients homozygous for the C allele had reduced left STG gray and white matter volumes in comparison to those homozygous for the G allele (p < 0.01 and p < 0.001, respectively).

CONCLUSIONS

This exploratory study suggests that NRG1 may be involved in determining STG size in schizophrenia, and may play a role in the neurogenetic basis of the language disturbances seen in this disorder. However, due to our small sample size, the results should be regarded as preliminary and replicated in a larger sample.

The CBCL 1.5-5 and the identification of preschoolers with autism in Italy

AIMS

To study the potential use of child behaviour checklist (CBCL) 1.5-5 scales for the early identification of preschoolers at risk of autism.

METHODS

CBCL scores of three groups of preschoolers were compared: (1) an experimental group of 101 preschoolers with autism spectrum disorder (ASD); (2) a control group of 95 preschoolers with other psychiatric disorders (OPD); (3) a control group of 117 preschoolers with typical development (TD). One-way analysis of variance (ANOVA), logistic regression with odds ratio (OR) and receiver operating characteristic (ROC) analyses were performed.

RESULTS

ANOVA revealed that ASD and OPD had significantly higher scores in almost all CBCL scales than TD. ASD presented significantly higher scores than OPD on Withdrawn, Attention Problems and Pervasive Developmental Problems (PDP) scales. Logistic regression analysis demonstrated that these same CBCL scales have validity in predicting the presence of an ASD towards both TD and OPD. ROC analysis indicated high sensitivity and specificity for PDP (0.85 and 0.90) and Withdrawn (0.89 and 0.92) scales when ASD is compared to TD. Specificity (0.60 for PDP and 0.65 for Withdrawn) decreases when comparing ASD and OPD CONCLUSIONS: The PDP and Withdrawn scales have a good predictive validity so that they could be proposed as a first-level tool to identify preschoolers at risk of autism in primary care settings. Problems regarding the lower specificity when comparing ASD v. OPD are discussed.

Time to abandon the bio-bio-bio model of psychosis: Exploring the epigenetic and psychological mechanisms by which adverse life events lead to psychotic symptoms

Mental health services and research have been dominated for several decades by a rather simplistic, reductionistic focus on biological phenomena, with minimal consideration of the social context within which genes and brains inevitably operate. This ‘medical model’ ideology, enthusiastically supported by the pharmaceutical industry, has been particularly powerful in the field of psychosis, where it has led to unjustified and damaging pessimism about recovery. The failure to find robust evidence of a genetic predisposition for psychosis in general, or ‘schizophrenia’ in particular, can be understood in terms of recently developed knowledge about how epigenetic processes turn gene transcription on and off through mechanisms that are highly influenced by the individual's socio-environmental experiences. To understand the emerging evidence of the relationship between adverse childhood events and subsequent psychosis, it is necessary to integrate these epigenetic processes, especially those involving the stress regulating functions of the HPA axis, with research about the psychological mechanisms by which specific types of childhood trauma can lead to specific types of psychotic experiences. The implications, for research, mental health services and primary prevention, are profound.

Declaration of Interest: None of the authors have any conflicts of interest in relation to this paper.

Illicit substance use and its correlates in first episode psychosis

OBJECTIVE

To determine if substance use (particularly cannabis) is more frequent among first episode psychosis patients and associated with a more problematic clinical presentation.

METHOD

All first episode psychosis (FEP) patients presenting to secondary services were recruited from London and Nottingham, over 2 years, in the Aetiology and Ethnicity of Schizophrenia and Other Psychoses study broad framework. Clinical and sociodemographic variables were assessed using a set of standardized instruments. A schedule was created to retrospectively collate substance use data from patients, relatives and clinicians.

RESULTS

Five hundred and eleven FEP were identified. They used three to five times more substances than general population. Substance use was associated with poorer social adjustment and a more acute mode of onset. Cannabis use did not affect social adjustment, but was associated with a more acute mode of onset.

CONCLUSION

Cannabis has a different impact on FEP than other substances. Large epidemiological studies are needed to disentangle cannabis effect.