A developmental look at the attentional system in the at risk and first episode of psychosis: age related changes in attention along the psychosis spectrum

Relationships between cognitive performance, clinical insight and regional brain volumes in schizophrenia

Impairments in cognitive performance are common in schizophrenia, and these contribute to poor awareness of symptoms and treatment (‘clinical insight’), which is an important predictor of functional outcome. Although relationships between cognitive impairment and reductions in regional brain volumes in patients are relatively well characterised, less is known about the brain structural correlates of clinical insight. To address this gap, we aimed to explore brain structural correlates of cognitive performance and clinical insight in the same sample. 108 patients with schizophrenia (SZH) and 94 age and gender-matched controls (CON) (from the Northwestern University Schizophrenia Data and Software Tool (NUSDAST) database) were included. SZH had smaller grey matter volume across most fronto-temporal regions and significantly poorer performance on all cognitive domains. Multiple regression showed that higher positive symptoms and poorer attention were significant predictors of insight in SZH; however, no significant correlations were seen between clinical insight and regional brain volumes. In contrast, symptomology did not contribute to cognitive performance, but robust positive relationships were found between regional grey matter volumes in fronto-temporal regions and cognitive performance (particularly executive function). Many of these appeared to be unique to SZH as they were not observed in CON. Findings suggest that while there exists a tight link between cognitive functioning and neuropathological processes affecting gross brain anatomy in SZH, this is not the case for clinical insight. Instead, clinical insight levels seem to be influenced by symptomology, attentional performance and other subject-specific variables.

Longitudinal effects of cannabis use on attentional processes in patients with first episode of psychosis

BACKGROUND

Attention deficits have been considered to be a central characteristic of schizophrenia-spectrum disorders. However, the specific interactions with, and longitudinal effects of, cannabis use at the different stages of the disorder remain unknown. Due to the high percentage of patients who are cannabis users at the onset of the disease, our objective was to explore this relationship and how it evolves in the first three years of the disease.

METHOD

A total of 461 patients with a first episode of psychosis (FEP) and 187 healthy controls were studied. The differences between cannabis users and non-users at baseline were explored based on both sociodemographic variables and performance in neuropsychological tests of attention. The interaction between cannabis, attentional, and clinical variables was followed up at 3 years.

RESULTS

Of the 648 participants included in this study, 229 (35.34%) were cannabis users. Of them, 187 (40.6%) were patients and 42 (22.5%) were healthy controls. At baseline, control groups [cannabis users (N = 42); non-users (N = 145)] outperformed the patient groups [cannabis users (N = 187); non-users (N = 274)] in all attention tasks. Longitudinal analyses showed significant improvements in the attentional domains at 3-year follow-up, mainly in the group of patients who had never used cannabis (N = 238), followed by ex-users (N = 105), and persistent users (N = 43). At 3-year follow-up, the group of ex-users was the one that achieved scores closer to those of healthy controls.

CONCLUSION

FEP patients, both cannabis users and non-users, showed attention deficits. However, the patients who had never used cannabis fared better than cannabis users.

Organization framework and preliminary findings from the Athens First-Episode Psychosis Research Study

AIMS

Athens First-Episode Psychosis (FEP) Research study, aims to explore the potential associations between multiple genetic, environmental and neurometabolic risk factors of psychotic disorders, through the clinical management of FEP patients with minimal exposure (<2 weeks) to antipsychotic treatment at entry. The goal of this paper is to introduce the background, rationale and design of the study and present its preliminary findings.

METHODS

We developed a longitudinal cohort study of FEP patients 16-45 years old, presenting at the emergency units of five psychiatric hospitals across Athens, Greece. Research timeline includes baseline, 1-month and 1-year follow-up. Clinical, genetic, environmental, cognitive and biochemical parameters are measured, using psychometric tools, clinical interviews and laboratory tests. A descriptive analysis of baseline and 1-month assessments was performed including demographic characteristics, family history, medication, clinical picture, traumatic experiences, drug use and cognitive functioning.

RESULTS

During the last 3 years, 130 subjects have been enrolled in the study. Data so far reveal that, despite the severity of baseline presentation, at 1-month the majority (57.4%) met the Andreasen symptom severity criteria for remission, without the time criterion and showed mild functional improvement. Several environmental adversities and poor cognitive performance were identified, which need to be further elaborated.

CONCLUSIONS

Athens FEP Research study is the first gene-environment interaction study in Greece. In this article we introduce the organization and methodological framework of the project, along with its basic initial findings. Future analysis will allow the validation of tractable predictors and risk factors implicated in the development and outcome of psychosis.

Cognition in at-risk mental states for psychosis

RATIONALE

The devastating nature of schizophrenia and treatment limitations have triggered a search for early detection methods to enable interventions to be implemented as soon as the first signs and symptoms appear. In this effort, several studies have investigated the cognitive functions in individuals regarded as being in at-risk mental states (ARMS) for psychosis.

OBJECTIVE

Our aim was to make a systematic review of the literature regarding basic and social cognition in individuals in ARMS following the guidelines of the PRISMA statement.

RESULTS

In general, the results of the 49 articles included in the review show that individuals in ARMS have pervasive cognitive deficits that seem to be greater in individuals who later convert to psychosis.

CONCLUSIONS

Cognitive impairment can be detected in individuals considered to be in ARMS according to current classifications and may serve as a risk marker for psychotic conversion; however, the lack of standardized criteria to define ARMS and of homogeneous cognitive assessment methods hamper the generalization of findings from different studies.

Demographic correlates of attenuated positive psychotic symptoms

It is now well established that the utilization of standardized clinical criteria can enhance prediction of psychosis. These criteria are primarily concerned with the presence and severity of attenuated positive symptoms. Because these symptom criteria are used to derive algorithms for designating clinical high risk (CHR) status and for maximizing prediction of psychosis risk, it is important to know whether the symptom ratings vary as a function of demographic factors that have previously been linked with symptoms in diagnosed psychotic patients. Using a sample of 356 CHR individuals from the NAPLS-II multi-site study, we examined the relation of three sex, age, and educational level, with the severity of attenuated positive symptom scores from the Scale of Prodromal Symptoms (SOPS). Demographic factors accounted for little of the variance in symptom ratings (5-6%). Older CHR individuals manifested more severe suspiciousness, and female CHR participants reported more unusual perceptual experiences than male participants. Contrary to prediction, higher educational level was associated with more severe ratings of unusual thought content, but less severe perceptual abnormalities. Overall, sex, age and education were modestly related to unusual thought content and perceptual abnormalities, only, suggesting minimal implication for designating CHR status and predicting psychosis-risk.

Paying attention to MMN in schizophrenia

The aim of this review is to explore the phenomenon of reduced mismatch negativity (MMN) in persons with schizophrenia and the possible relationship it has with attention impairments. In doing so we discuss (i) the prediction error account of MMN, (ii) reduced MMN as a faulty predictive processing system in persons with schizophrenia, (iii) the role of these systems in relevance filtering and attentional resource protection, (iv) attentional impairments in persons with schizophrenia, and (v) research that has explored MMN and attention in schizophrenia groups. Our review of the literature suggests that no study has appropriately examined the functional impact of smaller MMN in schizophrenia on the performance of a concurrent attention task. We conclude that future research should explore this notion further in the hope that it might embed MMN findings within outcomes of functional significance to individuals with the illness and those providing treatment. This article is part of a Special Issue entitled SI: Prediction and Attention.