Cognitive impairment as a risk factor for psychosis

Antecedents of major depressive, bipolar, and psychotic disorders: A systematic review and meta-analysis of prospective studies

Major depressive, bipolar, or psychotic disorders are preceded by earlier manifestations in behaviours and experiences. We present a synthesis of evidence on associations between person-level antecedents (behaviour, performance, psychopathology) in childhood, adolescence, or early adulthood and later onsets of major depressive disorder, bipolar disorder, or psychotic disorder based on prospective studies published up to September 16, 2022. We screened 11,342 records, identified 460 eligible publications, and extracted 570 risk ratios quantifying the relationships between 52 antecedents and onsets in 198 unique samples with prospective follow-up of 122,766 individuals from a mean age of 12.4 to a mean age of 24.8 for 1522,426 person years of follow-up. We completed meta-analyses of 12 antecedents with adequate data. Psychotic symptoms, depressive symptoms, anxiety, disruptive behaviors, affective lability, and sleep problems were transdiagnostic antecedents associated with onsets of depressive, bipolar, and psychotic disorders. Attention-deficit/hyperactivity and hypomanic symptoms specifically predicted bipolar disorder. While transdiagnostic and diagnosis-specific antecedents inform targeted prevention and help understand pathogenic mechanisms, extensive gaps in evidence indicate potential for improving early risk identification.

Schizophrenia in the genetic era: a review from development history, clinical features and genomic research approaches to insights of susceptibility genes

Schizophrenia is a devastating neuropsychiatric disorder affecting 1% of the world population and ranks as one of the disorders providing the most severe burden for society. Schizophrenia etiology remains obscure involving multi-risk factors, such as genetic, environmental, nutritional, and developmental factors. Complex interactions of genetic and environmental factors have been implicated in the etiology of schizophrenia. This review provides an overview of the historical origins, pathophysiological mechanisms, diagnosis, clinical symptoms and corresponding treatment of schizophrenia. In addition, as schizophrenia is a polygenic, genetic disorder caused by the combined action of multiple micro-effective genes, we further detail several approaches, such as candidate gene association study (CGAS) and genome-wide association study (GWAS), which are commonly used in schizophrenia genomics studies. A number of GWASs about schizophrenia have been performed with the hope to identify novel, consistent and influential risk genetic factors. Finally, some schizophrenia susceptibility genes have been identified and reported in recent years and their biological functions are also listed. This review may serve as a summary of past research on schizophrenia genomics and susceptibility genes (NRG1, DISC1, RELN, BDNF, MSI2), which may point the way to future schizophrenia genetics research. In addition, depending on the above discovery of susceptibility genes and their exact function, the development and application of antipsychotic drugs will be promoted in the future.

Is cognition integral to psychopathology? A population-based cohort study

BACKGROUND

Lower cognitive functioning has been documented across psychiatric disorders and hypothesized to be a core deficit of mental disorders. Situating psychopathology and cognition as part of a unitary construct is therefore important to understanding the etiology of psychiatric disorders. The current study aims to test competing structural models of psychopathology and cognition in a large national cohort of adolescents.

METHODS

The analytic sample consisted of 1189 participants aged 16-17 years, screened by the Israeli Draft Board. Psychopathology was assessed using a modified version of the Brief Symptom Inventory, and cognition was assessed based on four standardized test scores ((1) mathematical reasoning, concentration, and concept manipulation; (2) visual-spatial problem-solving skills and nonverbal abstract reasoning; (3) verbal understanding; (4) categorization and verbal abstraction). Confirmatory factor analysis was implemented to compare competing structural models of psychopathology with and without cognition. Sensitivity analyses examined the models in different subpopulations.

RESULTS

Confirmatory factor analysis indicated a better model fit of psychopathological symptoms without cognition (RMSEA = 0.037; TLI = 0.991; CFI = 0.992) than with cognition (RMSEA = 0.04-0.042; TLI = 0.987-0.988; CFI = 0.988-0.989). Sensitivity analyses supported the robustness of these results with a single exception. Among participants with low cognitive abilities (N = 139), models that integrated psychopathological symptoms with cognition had a better fit compared to models of psychopathology without cognition.

CONCLUSIONS

The current study suggests that cognition and psychopathology are, generally, independent constructs. However, within low cognitive abilities, cognition was integral to the structure of psychopathology. Our results point toward an increased vulnerability to psychopathology in individuals with low cognitive abilities and may provide valuable information for clinicians.

Intelligence trajectories in individuals at ultra-high risk for psychosis: An 8-year longitudinal analysis

Cognitive impairment is a well-documented predictor of transition to a full-threshold psychotic disorder amongst individuals at ultra-high risk (UHR) for psychosis. However, less is known about whether change in cognitive functioning differs between those who do and do not transition. Studies to date have not examined trajectories in intelligence constructs (e.g., acquired knowledge and fluid intelligence), which have demonstrated marked impairments in individuals with schizophrenia. This study aimed to examine intelligence trajectories using longitudinal data spanning an average of eight years, where some participants completed assessments over three time-points. Participants (N = 139) at UHR for psychosis completed the Wechsler Abbreviated Scale of Intelligence (WASI) at each follow-up. Linear mixed-effects models mapped changes in WASI Full-Scale IQ (FSIQ) and T-scores on Vocabulary, Similarities, Block Design, and Matrix Reasoning subtests. The sample showed stable and improving trajectories for FSIQ and all subtests. There were no significant differences in trajectories between those who did and did not transition to psychosis and between individuals with good and poor functional outcomes. However, although not significant, the trajectories of the acquired knowledge subtests diverged between transitioned and non-transitioned individuals (β = -0.12, 95 % CI [-0.29, 0.05] for Vocabulary and β = -0.14, 95 % CI [-0.33, 0.05] for Similarities). Overall, there was no evidence for long-term deterioration in intelligence trajectories in this UHR sample. Future studies with a larger sample of transitioned participants may be needed to explore potential differences in intelligence trajectories between UHR transition groups and other non-psychosis outcomes.

Adult outcome of preterm birth: Implications for neurodevelopmental theories of psychosis

Preterm birth is associated with an elevated risk of developmental and adult psychiatric disorders, including psychosis. In this review, we evaluate the implications of neurodevelopmental, cognitive, motor, and social sequelae of preterm birth for developing psychosis, with an emphasis on outcomes observed in adulthood. Abnormal brain development precipitated by early exposure to the extra-uterine environment, and exacerbated by neuroinflammation, neonatal brain injury, and genetic vulnerability, can result in alterations of brain structure and function persisting into adulthood. These alterations, including abnormal regional brain volumes and white matter macro- and micro-structure, can critically impair functional (e.g. frontoparietal and thalamocortical) network connectivity in a manner characteristic of psychotic illness. The resulting executive, social, and motor dysfunctions may constitute the basis for behavioural vulnerability ultimately giving rise to psychotic symptomatology. There are many pathways to psychosis, but elucidating more precisely the mechanisms whereby preterm birth increases risk may shed light on that route consequent upon early neurodevelopmental insult.

Comparison of two cognitive screening measures in a longitudinal sample of youth at-risk for psychosis

BACKGROUND

Validated screening tools are needed to detect subtle cognitive impairment in individuals at-risk for developing psychosis. Here, the utility of the Mini-Mental Status Examination (MMSE) and Penn Computerized Neurocognitive Battery (CNB) were evaluated for detecting cognitive impairment in individuals with psychosis spectrum (PS) symptoms.

METHODS

Participants (n = 229; 54 % female) completed the MMSE and CNB at baseline and two-year follow-up. PS (n = 91) and typically developing (TD; n = 138) participants were enrolled at baseline based on the presence or absence of PS symptoms. After two years, 65 participants remained PS, 104 participants remained TD, 23 participants had Emergent (EP) subthreshold PS symptoms, and 37 participants were experiencing Other Psychopathology (OP).

RESULTS

Generally, those with PS had lower scores than TD on both the MMSE (p < 0.0001) and CNB (p < 0.0001). Additionally, OP participants performed lower on the MMSE than TD (p = 0.02). Receiver operating characteristic (ROC) analyses indicated similar area under the curve (AUCs) for the two instruments (0.67); the MMSE showed higher specificity (0.71 vs. 0.62), while the CNB showed higher sensitivity (0.66 vs 0.52). Use of the MMSE and CNB in combination provided the highest diagnostic classification.

CONCLUSION

The MMSE and CNB can be used to screen for cognitive impairment in PS. The MMSE is better at ruling out PS-related cognitive impairment while the CNB is better at ruling in PS-related cognitive impairment. Overall, our results indicate that both tests are useful in screening for cognitive impairment, particularly in combination, in a PS population.

Insula sub-regions across the psychosis spectrum: morphology and clinical correlates

The insula is a heterogeneous cortical region, comprised of three cytoarchitecturally distinct sub-regions (agranular, dysgranular, and granular), which traverse the anterior-posterior axis and are differentially involved in affective, cognitive, and somatosensory processing. Smaller insula volume is consistently reported in psychosis-spectrum disorders and is hypothesized to result, in part, from abnormal neurodevelopment. To better understand the regional and diagnostic specificity of insula abnormalities in psychosis, their developmental etiology, and clinical correlates, we characterized insula volume and morphology in a large group of adults with a psychotic disorder (schizophrenia spectrum, psychotic bipolar disorder) and a community-ascertained cohort of psychosis-spectrum youth (age 8-21). Insula volume and morphology (cortical thickness, gyrification, sulcal depth) were quantified from T1-weighted structural brain images using the Computational Anatomy Toolbox (CAT12). Healthy adults (n = 196), people with a psychotic disorder (n = 303), and 1368 individuals from the Philadelphia Neurodevelopmental Cohort (PNC) (381 typically developing (TD), 381 psychosis-spectrum (PS) youth, 606 youth with other psychopathology (OP)), were investigated. Insula volume was significantly reduced in adults with psychotic disorders and psychosis-spectrum youth, following an anterior-posterior gradient across granular sub-regions. Morphological abnormalities were limited to lower gyrification in psychotic disorders, which was specific to schizophrenia and associated with cognitive ability. Insula volume and thickness were associated with cognition, and positive and negative symptoms of psychosis. We conclude that smaller insula volume follows an anterior-posterior gradient in psychosis and confers a broad risk for psychosis-spectrum disorders. Reduced gyrification is specific to schizophrenia and may reflect altered prenatal development that contributes to cognitive impairment.

Cognitive markers related to long-term remission status in Schizophrenia Spectrum Disorders

Cognitive impairment is an established feature of schizophrenia. From a cross-sectional perspective, studies have revealed associations between cognition and remission. Few studies have examined this relationship longitudinally. Here we examine which cognitive domains might be related to long-term remission and symptomatic severity. The present study followed 173 outpatients with schizophrenia for five years, divided into groups based on long-term remission status and symptomatic severity, assessed with the Positive and Negative Syndrome Scale. Cognitive functioning was assessed at baseline, with tests of vigilance, executive functions, processing speed, memory and learning, working memory, and premorbid functioning. Cognitive domains related to long-term remission status were executive functions, working memory, and premorbid functioning. The most prominent cognitive differences were found between the group in stable remission with minimal symptoms, and the non-remission group, the first group demonstrating better cognitive functioning. The study highlights the role of premorbid functioning as a cognitive feature in the prediction of long-term remission. It also indicates the possibility of viewing specific cognitive domains as markers for clinical outcome, highlighting the value of early assessment of cognition. In summary, a certain cognitive profile, in coexistence with long-term non-remission, suggests poorer outcome. Hence, this group is in need of increased support.

A qualitative study of the acceptability of cognitive bias modification for paranoia (CBM-pa) in patients with psychosis

BACKGROUND

Cognitive Bias Modification (CBM) has been used successfully as a computer-based intervention in disorders such as anxiety. However, CBM to modify interpretations of ambiguous information relevant to paranoia has not yet been tested. We conducted a qualitative investigation of a novel intervention called CBM for paranoia (CBM-pa) to examine its acceptability in patients with psychosis.

METHODS

Eight participants with psychosis who completed CBM-pa were identified by purposive sampling and invited for a semi-structured interview to explore the facilitators and barriers to participation, optimum form of delivery, perceived usefulness of CBM-pa and their opinions on applying CBM-pa as a computerised intervention. The interviews were transcribed and analysed using thematic analysis by researchers working in collaboration with service users.

RESULTS

Themes emerged relating to participants' perception about delivery, engagement, programme understanding, factors influencing experience, perceived impact and application of CBM-pa. CBM-pa was regarded as easy, straightforward and enjoyable. It was well-accepted among those we interviewed, who understood the procedure as a psychological intervention. Patients reported that it increased their capacity for adopting alternative interpretations of emotionally ambiguous scenarios. Although participants all agreed on the test-like nature of the current CBM-pa format, they considered that taking part in sessions had improved their overall wellbeing. Most of them valued the computer-based interface of CBM-pa but favoured the idea of combining CBM-pa with some form of human interaction.

CONCLUSIONS

CBM-pa is an acceptable intervention that was well-received by our sample of patients with paranoia. The current findings reflect positively on the acceptability and experience of CBM-pa in the target population. Patient opinion supports further development and testing of CBM-pa as a possible adjunct treatment for paranoia.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN: 90749868 . Retrospectively registered on 12 May 2016.

Longitudinal Cognitive Changes in Young Individuals at Ultrahigh Risk for Psychosis

IMPORTANCE

Cognitive deficits are a key feature of risk for psychosis. Longitudinal changes in cognitive architecture may be associated with the social and occupational functioning in young people.

OBJECTIVES

To examine longitudinal profiles of cognition in individuals at ultrahigh risk (UHR) for psychosis, compared with healthy controls, and to investigate the association of cognition with functioning.

DESIGN, SETTING, AND PARTICIPANTS

This study has a multiple-group prospective design completed in 24 months and was conducted from January 1, 2009, to November 11, 2012, as part of the Longitudinal Youth at-Risk Study conducted in Singapore. Participants either were recruited from psychiatric outpatient clinics, educational institutions, and community mental health agencies or self-referred. Follow-up assessments were performed every 6 months for 2 years or until conversion to psychosis. Individuals with medical causes for psychosis, current illicit substance use, or color blindness were excluded. Data analysis was conducted from June 2014 to May 2018.

MAIN OUTCOMES AND MEASURES

Neuropsychological, perceptual, and social cognitive tasks; semi-structured interviews, and the Structured Clinical Interview for DSM-IV Axis I disorders were administered every 6 months. The UHR status of nonconverters, converters, remitters, and nonremitters was monitored. Cognitive domain scores and functioning were investigated longitudinally.

RESULTS

In total, 384 healthy controls and 173 UHR individuals between ages 14 and 29 years were evaluated prospectively. Of the 384 healthy controls, 153 (39.8%) were female and 231 (60.2%) were male with a mean (SD) age of 21.69 (3.26) years. Of the 173 individuals at UHR for psychosis, 56 (32.4%) were female and 117 (67.6%) were male with a mean (SD) age of 21.27 (3.52) years). After 24 months of follow-up, 383 healthy controls (99.7%) and 122 individuals at UHR for psychosis (70.5%) remained. Baseline cognitive deficits were associated with psychosis conversion later (mean odds ratio [OR], 1.66; combined 95% CI, 1.08-2.83; P = .04) and nonremission of UHR status (mean OR, 1.67; combined 95% CI, 1.09-2.95; P = .04). Five cognitive components-social cognition, attention, verbal fluency, general cognitive function, and perception-were obtained from principal components analysis. Longitudinal component structure change was observed in general cognitive function (maximum vertical deviation = 0.59; χ2 = 8.03; P = .01). Group-by-time interaction on general cognitive function (F = 12.23; η2 = 0.047; P < .001) and perception (F = 8.33; η2 = 0.032; P < .001) was present. Changes in attention (F = 5.65; η2 = 0.013; P = .02) and general cognitive function (F = 7.18; η2 = 0.014; P = .01) accounted for longitudinal changes in social and occupational functioning.

CONCLUSIONS AND RELEVANCE

Individuals in this study who met the UHR criteria appeared to demonstrate cognitive deficits, and those whose UHR status remitted were seen to recover cognitively. Cognition appeared as poor in nonremitters and appeared to be associated with poor functional outcome. This study suggests that cognitive dimensions are sensitive to the identification of young individuals at risk for psychosis and to the longitudinal course of those at highest risk.

Maternal deprivation induces alterations in cognitive and cortical function in adulthood

Early life trauma is a risk factor for a number of neuropsychiatric disorders, including schizophrenia (SZ). The current study assessed how an early life traumatic event, maternal deprivation (MD), alters cognition and brain function in rodents. Rats were maternally deprived in the early postnatal period and then recognition memory (RM) was tested in adulthood using the novel object recognition task. The expression of catechol-o-methyl transferase (COMT) and glutamic acid decarboxylase (GAD67) were quantified in the medial prefrontal cortex (mPFC), ventral striatum, and temporal cortex (TC). In addition, depth EEG recordings were obtained from the mPFC, vertex, and TC during a paired-click paradigm to assess the effects of MD on sensory gating. MD animals exhibited impaired RM, lower expression of COMT in the mPFC and TC, and lower expression of GAD67 in the TC. Increased bioelectric noise was observed at each recording site of MD animals. MD animals also exhibited altered information theoretic measures of stimulus encoding. These data indicate that a neurodevelopmental perturbation yields persistent alterations in cognition and brain function, and are consistent with human studies that identified relationships between allelic differences in COMT and GAD67 and bioelectric noise. These changes evoked by MD also lead to alterations in shared information between cognitive and primary sensory processing areas, which provides insight into how early life trauma confers a risk for neurodevelopmental disorders, such as SZ, later in life.

The role of cognitive functioning in the relationship between childhood trauma and a mixed phenotype of affective-anxious-psychotic symptoms in psychotic disorders

Cognitive impairments in patients with psychotic disorder have been associated with poor functioning and increased symptom severity. Furthermore, childhood trauma (CT) exposure has been associated with worse cognitive functioning as well as co-occurrence of affective-anxious-psychosis symptoms or a 'mixed phenotype of psychopathology' (MP), which in turn is associated with greater symptom severity, and poor functioning. This study aims to evaluate if cognition could be associated with CT/MP. 532 patients with non-affective psychotic patients were assessed on CT, symptom profile, cognition, functioning, and symptom severity at baseline and 3 and 6-year follow-up. Four subgroups were made according to trauma exposure (CT- or CT+) and presence of a mixed phenotype (MP- or MP+): CT-/MP (n=272), CT-/MP+ (n=157), CT+/MP- (n=49), and CT+/MP+ (n=54). Mixed-effects multilevel regression, linear regression, and Tobit analyses were performed. Patients with both CT and MP showed lower verbal learning and memory than CT-/MP+ individuals (p<0.001). No other significant differences were found among the 4 subgroups. No cognitive decline was found at follow-up, neither in the CT+/MP- nor in CT-/MP- group. Lower cognition was not associated with increased symptom severity or poor functioning at follow-up, neither in the CT+/MP- nor in CT-/MP- group. Although cognitive impairments and CT may be related to clinical or functional features of psychotic disorder, and cognitive functioning could be affected by CT exposure, cognition does not discriminate subgroups of patients stratified by CT exposure and MP.

Cannabis use and psychotic-like experiences trajectories during early adolescence: the coevolution and potential mediators

BACKGROUND

The authors sought to model the different trajectories of psychotic-like experiences (PLE) during adolescence and to examine whether the longitudinal relationship between cannabis use and PLE is mediated by changes in cognitive development and/or change in anxiety or depression symptoms.

METHODS

A total of 2,566 youths were assessed every year for 4-years (from 13- to 16-years of age) on clinical, substance use and cognitive development outcomes. Latent class growth models identified three trajectories of PLE: low decreasing (83.9%), high decreasing (7.9%), and moderate increasing class (8.2%). We conducted logistic regressions to investigate whether baseline levels and growth in cannabis use were associated with PLE trajectory membership. Then, we examined the effects of potential mediators (growth in cognition and anxiety/depression) on the relationship between growth in cannabis use and PLE trajectory.

RESULTS

A steeper growth in cannabis use from 13- to 16-years was associated with a higher likelihood of being assigned to the moderate increasing trajectory of PLE [odds ratio, 2.59; 95% confidence interval (CI), 1.11-6.03], when controlling for cumulative cigarette use. Growth in depression symptoms, not anxiety or change in cognitive functioning, mediated the relationship between growth in cannabis use and the PLE moderate increasing group (indirect effect: 0.07; 95% CI, 0.03-0.11).

CONCLUSIONS

Depression symptoms partially mediated the longitudinal link between cannabis use and PLE in adolescents, suggesting that there may be a preventative effect to be gained from targeting depression symptoms, in addition to attempting to prevent cannabis use in youth presenting increasing psychotic experiences.

Cognitive biases mediate the relationship between temperament and character and psychotic-like experiences in healthy adults

Psychotic-like experiences (PLEs) are frequently reported in the general population. Healthy individuals reporting PLEs have a similar personality profile to people with psychosis; however, the mechanisms by which personality influences PLEs are unclear. This study tests the hypothesis that cognitive biases mediate the relationship between two dimensions of personality (i.e. temperament and character) and positive and negative PLEs. Two hundred and ninety-six healthy participants were assessed using the Community Assessment of Psychic Experiences scale, the Temperament and Character Inventory and the Davos Scale for Cognitive Biases. We performed multiple stepwise regression analysis and mediation analysis according to Baron and Kenny׳s method. Harm-avoidance and self-directedness personality dimensions significantly predicted PLEs frequency. High self-transcendence and lower cooperativeness predicted positive PLEs. Cognitive biases were significant mediators in relationships between temperament, character and both positive and negative PLEs. In particular, attention to threat and external attribution biases fully mediate the relationship between cooperativeness and positive PLEs. Other cognitive biases partially mediate the relationships between self-transcendence and positive PLEs and self-directedness, harm-avoidance and negative PLEs. Our study tentatively suggests that personality may influence PLEs via the cognitive bias pathway.

Adding insult to injury: childhood and adolescent risk factors for psychosis predict lower fractional anisotropy in the superior longitudinal fasciculus in healthy adults

Although epidemiological studies provide strong support for demographic and environmental risk factors in psychotic disorders, few data examine how these risk factors relate to the putative aberrant neurodevelopment associated with illness. The present study examined how the accumulation of risk factors including low IQ, low parental socioeconomic status (SES), history of adolescent cannabis use and childhood trauma, and high levels of subclinical psychotic-like experiences (PLEs) contributed to aberrant neurodevelopmental outcomes in 112 otherwise healthy adults recruited from the community. Participants were studied with diffusion tensor imaging (DTI), and voxel-wise statistical analysis of fractional anisotropy (FA) using tract-based spatial statistics (TBSS) was used to examine the relation between cumulative risk (CR) for psychosis and white matter (WM) integrity across the whole brain. Analyses revealed that higher CR was significantly associated with lower FA in a cluster in the left superior longitudinal fasciculus (SLF). These results suggest that risk factors previously associated with psychotic disorders are associated with WM integrity even in otherwise healthy adults and may provide insight into how previously identified risk factors contribute to the structural brain abnormalities associated with psychotic illness. Prospective longitudinal studies examining the effect of risk factors on the developmental trajectory of brain WM are warranted.

Changes in aspects of cognitive functioning in young patients with schizophrenia during group psychodynamic psychotherapy: a preliminary study

BACKGROUND

The "Sveti Ivan" psychiatric hospital in Zagreb, Croatia, offers an outpatient Early Intervention Program for psychotic patients. This program consists of psycho-educational workshops and group psychodynamic psychotherapy. Two important objectives of the program are improving and maintaining adequate cognitive functioning.

AIMS

The current study examined changes in aspects of cognitive functioning in young patients with schizophrenia after 18 months and after 3 years of psychodynamic group psychotherapy.

METHODS

The study included 28 patients who attended the Early Intervention Program for young patients with psychotic disorders; 10 patients had completed only the psycho-educational part of the program (comparative group), and 18 patients continued with group psychodynamic psychotherapy (experimental group). All patients completed the Revised Beta Examination.

RESULTS

We observed a trend in the experimental group to achieve higher scores than the comparative group. The results for both groups tended to increase with time, and this increase was greater in the experimental group.

CONCLUSIONS

While acknowledging the limitations of this preliminary study, we conclude that participating in psychodynamic group psychotherapy is related to increases in the cognitive functioning of patients with schizophrenia, and our results provide a sound basis for future research.

Precursors of cognitive impairments in psychotic disorders: a population-based study

Cognitive deficits have been found to be more prevalent in psychotic than in other disorders. Longitudinal research has shown that these deficits were generally already existent before onset of illness and are therefore not necessarily attributable to neurodegenerative processes. This study investigated whether both low IQ and markers of premorbid cognitive dysfunction independently contribute to an increased risk for psychoses. In a cross-sectional study about 50,000 young Swiss males completed a survey of intellectual problems in childhood/adolescence and other vulnerability factors during military call-up in 2005/2006. Subsequently, military IQ assessments were carried out on the entire sample. Diagnostic assessments were conducted according to International Classification of Diseases-10th edition (ICD-10). Low, especially performance, IQ was highly associated with an increased risk for psychotic disorders after adjusting for preexisting cognitive deficits and covariates, while in other disorders this association was less marked. Furthermore, preexisting intellectual problems emerged as important risk factors for psychoses. Our results confirm the importance of low IQ as characteristic of psychoses. Although premorbid intellectual deficits are common in people who go on to develop psychosis, neurodegenerative disease processes may also precipitate further declines in fluid cognitive functions. Assessment of cognitive functioning should be taken into account in early detection of psychoses.

Social cognitive role of schizophrenia candidate gene GABRB2

The occurrence of positive selection in schizophrenia-associated GABRB2 suggests a broader impact of the gene product on population fitness. The present study considered the possibility of cognition-related GABRB2 involvement by examining the association of GABRB2 with psychosis and altruism, respectively representing psychiatric and psychological facets of social cognition. Four single nucleotide polymorphisms (SNPs) were genotyped for quantitative trait analyses and population-based association studies. Psychosis was measured by either the Positive and Negative Syndrome Scale (PANSS) or antipsychotics dosage, and altruism was based on a self-report altruism scale. The minor alleles of SNPs rs6556547, rs1816071 and rs187269 in GABRB2 were correlated with high PANSS score for positive symptoms in a Han Chinese schizophrenic cohort, whereas those of rs1816071 and rs1816072 were associated with high antipsychotics dosage in a US Caucasian schizophrenic cohort. Moreover, strongly significant GABRB2-disease associations were found among schizophrenics with severe psychosis based on high PANSS positive score, but no significant association was observed for schizophrenics with only mild psychosis. Interestingly, in addition to association with psychosis in schizophrenics, rs187269 was also associated with altruism in healthy Han Chinese. Furthermore, parallel to correlation with severe psychosis, its minor allele was correlated with high altruism scores. These findings revealed that GABRB2 is associated with psychosis, the core symptom and an endophenotype of schizophrenia. Importantly, the association was found across the breadth of the psychiatric (psychosis) to psychological (altruism) spectrum of social cognition suggesting GABRB2 involvement in human cognition.

Body weight and ADHD: examining the role of self-regulation

OBJECTIVE

Attention-Deficit/Hyperactivity Disorder (ADHD) is a complex and heterogeneous childhood disorder that often coexists with other psychiatric and somatic disorders. Recently, a link between ADHD and body weight dysregulation has been reported and often interpreted as impaired self-regulation that is shared between the two conditions. The objective of this study is to investigate the relation between body weight/BMI and cognitive, emotional and motor characteristics in children with ADHD.

METHODS

284 ADHD children were stratified by weight status/BMI according to WHO classification and compared with regard to their neurocognitive characteristics, motivational style, and motor profile as assessed by a comprehensive battery of tests. All comparisons were adjusted for demographic characteristics of relevance including, socioeconomic status (SES).

RESULTS

Both Obese and overweight ADHD children exhibited significantly lower SES compared to normal weight ADHD children. No significant differences were observed between the three groups with regards to their neurocognitive, emotional and motor profile.

CONCLUSIONS

Our findings provide evidence that differences in weight/BMI are not accounted for by cognitive, motivational and motor profiles. Socio-economic characteristics are strongly associated with overweight and obesity in ADHD children and may inform strategies aimed at promoting healthier weight.

Behavioral animal models of antipsychotic drug actions

Basic research in animals represents a fruitful approach to study the neurobiological basis of brain and behavioral disturbances relevant to neuropsychiatric disease and to establish and evaluate novel pharmacological therapies for their treatment. In the context of schizophrenia, there are models employing specific experimental manipulations developed according to specific pathophysiological or etiological hypotheses. The use of selective lesions in adult animals and the acute administration of psychotomimetic agents are indispensable tools in the elucidation of the contribution of specific brain regions or neurotransmitters to the genesis of a specific symptom or collection of symptoms and enjoy some degrees of predictive validity. However, they may be inaccurate, if not inadequate, in capturing the etiological mechanisms or ontology of the disease needed for a complete understanding of the disease and may be limited in the discovery of novel compounds for the treatment of negative and cognitive symptoms of schizophrenia. Under the prevailing consensus of schizophrenia as a disease of neurodevelopmental origin, we have seen the establishment of neurodevelopmental animal models which aim to identify the etiological processes whereby the brain, following specific triggering events, develops into a "schizophrenia-like brain" over time. Many neurodevelopmental models such as the neonatal ventral hippocampus (vHPC) lesion, methylazoxymethanol (MAM), and prenatal immune activation models can mimic a broad spectrum of behavioral, cognitive, and pharmacological abnormalities directly implicated in schizophrenic disease. These models allow pharmacological screens against multiple and coexisting schizophrenia-related dysfunctions while incorporating the disease-relevant concept of abnormal brain development. The multiplicity of existing models is testimonial to the multifactorial nature of schizophrenia, and there are ample opportunities for their integration. Indeed, one ultimate goal must be to incorporate the successes of distinct models into one unitary account of the complex disorder of schizophrenia and to use such unitary approaches in the further development and evaluation of novel antipsychotic treatment strategies.

Inflammatory processes in schizophrenia: a promising neuroimmunological target for the treatment of negative/cognitive symptoms and beyond

Emerging evidence indicates that schizophrenia is associated with activated peripheral and central inflammatory responses. Such inflammatory processes seem to be influenced by a number of environmental and genetic predisposition factors, and they may critically depend on and contribute to the progressive nature of schizophrenic disease. There is also appreciable evidence to suggest that activated inflammatory responses can undermine disease-relevant affective, emotional, social, and cognitive functions, so that inflammatory processes may be particularly relevant for the precipitation of negative and cognitive symptoms of schizophrenia. Recent clinical trials of anti-inflammatory pharmacotherapy in this disorder provide promising results by showing superior beneficial treatment effects when standard antipsychotic drugs are co-administered with anti-inflammatory compounds, as compared with treatment outcomes using antipsychotic drugs alone. Given the limited efficacy of currently available antipsychotic drugs to ameliorate negative and cognitive symptoms, the further exploration of inflammatory mechanisms and anti-inflammatory strategies may open fruitful new avenues for improved treatment of symptoms undermining affective, emotional, social and cognitive functions pertinent to schizophrenic disease.

Effects on cognitive functioning after olanzapine-ziprasidone crossover in recent-onset schizophrenia

INTRODUCTION

To enhance functional outcome in schizophrenia improvement of cognitive symptoms is crucial.

EXPERIMENTAL PROCEDURES

Using a comprehensive test battery, this follow-up examines cognitive effects in patients with recent-onset schizophrenia after a change of medication following insufficient clinical response and intolerance.

RESULTS

After eight weeks cognitive outcomes had not improved in the patients having switched from olanzapine to ziprasidone (n=11; mean dose 136 mg) nor in those having switched from ziprasidone to olanzapine (n=10; mean 16 mg), while the symptoms of patients maintaining olanzapine (n=18; mean 10.9 mg) or ziprasidone (n=18; mean 88.9 mg) treatment had not improved further.

DISCUSSION

The findings suggest that also in early-stage schizophrenia the antipsychotics tested affect cognitive symptoms similarly.

Beyond the first episode: candidate factors for a risk prediction model of schizophrenia

Many early psychosis services are financially compromised and cannot offer a full tenure of care to all patients. To maintain viability of services it is important that those with schizophrenia are identified early to maximize long-term outcomes, as are those with better prognoses who can be discharged early. The duration of untreated psychosis remains the mainstay in determining those who will benefit from extended care, yet its ability to inform on prognosis is modest in both the short and medium term. There are a number of known or putative genetic and environmental risk factors that have the potential to improve prognostication, though a multivariate risk prediction model combining them with clinical characteristics has yet to be developed. Candidate risk factors for such a model are presented, with an emphasis on environmental risk factors. More work is needed to corroborate many putative factors and to determine which of the established factors are salient and which are merely proxy measures. Future research should help clarify how gene-environment and environment-environment interactions occur and whether risk factors are dose-dependent, or if they act additively or synergistically, or are redundant in the presence (or absence) of other factors.

Neurophysiological characteristics of cognitive functions in patients with first episodes of endogenous psychosis

This report presents studies of the neurophysiological correlates of the characteristics of cognitive disorders in patients with first psychotic episodes of endogenous psychosis at juvenile age. Three groups of patients were studied: those with a predominance of catatonic symptomatology (22 patients), those with a predominance of hallucinatory-delusional symptomatology (22 patients), and those with a predominance of affective-delusional symptomatology (24 patients), along with a group of psychologically healthy subjects (15 subjects). Parameters of auditory evoked potentials were analyzed using the oddball paradigm. The group with a predominance of catatonic disorders showed the greatest differences in the latent periods (LP) of the N200 and P300 components as compared with the other groups; patients with a predominance of hallucinatory-delusional symptomatology showed the most localized anomalies in the latent period of the P300 component; the group of patients dominated by affective-delusional symptomatology showed almost no increase in the latent period of the N200 component, though the extents of anomalies in the N100 component in responses to non-target signals and deviations in the P300 component were more marked than in the other groups. These characteristics of the neurophysiological correlates of cognitive functions in each group of patients supported the significance of evaluating the psychopathological structure of manifest psychotic episodes for determining the clinical typology.

Predicting domain-specific insight of schizophrenia patients from symptomatology, multiple neurocognitive functions, and personality related traits

This study examines the contribution of various neurocognitive functions, clinical characteristics, and personality traits to the prediction of three insight dimensions. Clinically stable schizophrenia patients (n=107) residing in the community were evaluated using the Positive and Negative Syndrome Scale, the Scale for the Assessment of Unawareness of Mental Disorder, and a comprehensive battery of instruments to measure personality related variables and neurocognitive functioning. Step-wise multivariate regression analysis indicates significant association of variability in insight dimensions with neurocognitive functioning (20-41%), personality related traits (8-18% temperament factors, 4-7% self-constructs, 10-14% coping styles), severity of symptoms (about 7%), illness duration (6%), and education (about 5%). Poor insight was attributed to impairment in visual and movement skills, sustained attention, executive functions, intensity of autistic preoccupations and positive symptoms, as well as increased novelty seeking behavior, task and emotion oriented coping styles, better self-esteem, self-efficacy, and higher education. Better awareness was related to better performance of neurocognitive tasks, reward dependence behavior, avoidant coping style, and longer illness duration. Aside from common indicators for the various insight dimensions, we defined specific indicators for each insight dimension. Thus, insight dimensions in schizophrenia patients residing in the community were attributed to neurocognitive and personality related factors rather than to psychopathological symptoms. The findings enable better understanding of the multifactorial nature of insight and highlight targets for more effective intervention and rehabilitation.

The treatment of schizophrenia: from premorbid manifestations to the first episode of psychosis

To achieve the best therapeutic results in schizophrenia--like most other disorders--primary prevention is preferable to early and prompt treatment, which, in turn, is preferable to treatment of chronically established illness. Unfortunately, there currently exist no accurate markers that can provide information regarding the future course of illness and guide treatment in asymptomatic or mildly symptomatic individuals. Therefore, most treatment efforts are currently focused on patients who have already experienced their first psychotic episode. This paper reviews the efforts to identify accurate markers heralding psychotic illness, as well as treatment considerations in the early phase of the disease.

The treatment of schizophrenia: from premorbid manifestations to the first episode of psychosis

To achieve the best therapeutic results in schizophrenia--like most other disorders--primary prevention is preferable to early and prompt treatment, which, in turn, is preferable to treatment of chronically established illness. Unfortunately, there currently exist no accurate markers that can provide information regarding the future course of illness and guide treatment in asymptomatic or mildly symptomatic individuals. Therefore, most treatment efforts are currently focused on patients who have already experienced their first psychotic episode. This paper reviews the efforts to identify accurate markers heralding psychotic illness, as well as treatment considerations in the early phase of the disease.