Cognitive ability and metabolic physical health in first-episode psychosis

Deconstructing Cognitive Impairment in Psychosis With a Machine Learning Approach

Importance

Cognitive functioning is associated with various factors, such as age, sex, education, and childhood adversity, and is impaired in people with psychosis. In addition to specific effects of the disorder, cognitive impairments may reflect a greater exposure to general risk factors for poor cognition.

Objective

To determine the extent that impairments in cognition in psychosis reflect risk factor exposures.

Design, Setting, and Participants

This cross-sectional study examined the relationship between exposures and cognitive function using data from the Bipolar-Schizophrenia Network on Intermediate Phenotypes studies 1 and 2 across 6 sites. Participants included healthy controls; patients with schizophrenia, schizoaffective disorder, or bipolar I disorder with psychosis; and relatives of patients. Predictive modeling was performed using extreme gradient boosting regression to train a composite cognitive score prediction model with nested cross-validation. Shapley additive explanations values were used to examine the relationship between exposures and cognitive function.

Exposure

Exposures were chosen based on associations with cognition previously identified: age, sex, race and ethnicity, childhood adversity, education, parental education, parental socioeconomic status, parental age at birth, substance use, antipsychotic dose, and diagnosis.

Main Outcomes and Measures

Cognition was assessed using the Brief Assessment of Cognition in Schizophrenia.

Results

A total of 3370 participants were included: 840 healthy controls, 709 patients with schizophrenia, 541 with schizoaffective disorder, 457 with bipolar I disorder with psychosis, and 823 relatives of patients. The mean (SD) age was 37.9 (13.3) years; 1887 were female (56%) and 1483 male (44%). The model predicted cognitive scores with high accuracy: out-of-sample Pearson correlation between predicted and observed cognitive composite score was r = 0.72 (SD = 0.03). Individuals with schizophrenia (z = -1.4), schizoaffective disorder (z = -1.2), and bipolar I disorder with psychosis (z = -0.5) all had significantly worse cognitive composite scores than controls. Factors other than diagnosis and medication accounted for much of this impairment (schizophrenia z = -0.73, schizoaffective disorder z = -0.64, bipolar I disorder with psychosis z = -0.13). Diagnosis accounted for a lesser proportion of this deficit (schizophrenia z = -0.29, schizoaffective disorder z = -0.15, bipolar I disorder with psychosis z = -0.13), and antipsychotic use accounted for a similar deficit across diagnostic groups (schizophrenia z = -0.37, schizoaffective disorder z = -0.33, bipolar I disorder with psychosis z = -0.26).

Conclusions and Relevance

This study found that transdiagnostic factors accounted for a meaningful share of the variance in cognitive functioning in psychosis. A significant proportion of the cognitive impairment in psychosis may reflect factors relevant to cognitive functioning in the general population. When considering interventions, a diagnosis-agnostic, symptom-targeted approach may therefore be appropriate.

Sex differences in the association of overweight with cognitive performance in individuals with first-episode psychosis

Cognitive deficits and overweight are prominent challenges in the treatment of psychosis, which have a direct impact on patients' quality of life. We aim to determine whether there is an association of overweight with cognitive performance and whether there are sex differences in this association. We included 170 individuals with first-episode psychosis (FEP) (mean age 23.08 years, 32.9% females) attending an early intervention service who underwent clinical, biometric, and cognitive assessments by the MATRICS Consensus Cognitive Battery. A set of two-way analyses of covariance (ANCOVAs) were conducted for each cognitive test. Sex, overweight, and their interaction were included as factors. Nearly 34% of the participants were overweight without differences between males and females. The excess of weight did not exert any main effect on cognition; however, overweight females performed significantly worse than non-overweight females in processing speed, verbal learning and memory, reasoning and problem-solving, and global cognitive function, whereas in males, there were no differences. Our findings highlight that sex matters in the study of metabolic and cognitive factors in FEP to develop targeted interventions based on sex perspectives.

Impact of cognitive reserve in clinical, neurocognitive and lifestyle factors in chronic schizophrenia and early stages of schizophrenia

INTRODUCTION

Although there is evidence that higher cognitive reserve (CR) is a protective factor and it has been related to better prognosis, there have been no studies to date that have explored the CR level and its impact in clinical, neurocognitive and lifestyle outcomes according to the stage of the disease: early stage of psychosis (ESP) or chronic schizophrenia (SCZ).

MATERIAL AND METHODS

A total of 60 patients in the ESP and 225 patients with SCZ were enrolled in the study. To test the predictive capacity of CR for each diagnostic group, a logistic regression analysis was conducted. Hierarchical linear regression analyses were performed to explore the associations between CR and different outcomes. The mediation analyses were performed according to the principles of Baron and Kenny.

RESULTS

Patients with SCZ showed lower CR than those in the ESP (p<0.001). CR correctly classified 79.6% of the cases (p<0.001; Exp(B)=1.062). In ESP group, CR was related to working memory (p=0.030) and negative symptoms (p=0.027). CR (t=3.925, p<0.001) and cannabis use (t=2.023, p=0.048) explained 26.7% of the variance on functioning (p=0.003). In patients with SCZ, CR predicted all cognitive domains, negative symptoms (R2=0.091, p=0.001) and functioning (R2=0.074, p=0.005). In both ESP and SCZ groups, higher CR was associated with lower body mass index and circumference. In ESP group, the effect of adherence to Mediterranean diet on functioning (p=0.037) was mediated by CR level (p=0.003).

CONCLUSIONS

The implications of CR depend on the stage of the disease (ESP vs. SCZ), with a greater effect on neurocognition and negative symptoms in patients with chronic SCZ.

The Effects of Hopelessness and Some Variables on Metabolic Syndrome in Schizophrenia Patients

This is a descriptive study conducted to determine the prevalence of Metabolic Syndrome (MetS) in Schizophrenia patients and identify the effects of hopelessness and some variables on MetS. The study was conducted at the Psychiatry Clinic of a university hospital in Turkey between May and August 2020 with 105 schizophrenia patients receiving treatment as inpatients. The data of the study were collected by a Personal Information Form, a Physiological Measurements Form and (BHS). The data were analyzed by using SPSS 25. The mean age of the patients was 35.31 ± 9.07, their mean duration of disease was 11.35 ± 9.07 years, and 60.0% of the patients were using atypical antipsychotics as their latest drug treatment. 42.9% of the patients had MetS, while the mean hopelessness level of those with MetS was 10.84 ± 3.81. It was determined that hopelessness levels and some sociodemographic (age) and clinical variables significantly predicted the MetS status in the schizophrenia patients.

Impact of smoking Behavior on cognitive functioning in persons at risk for psychosis and healthy controls: A longitudinal study

Background

The high prevalence of smoking in individuals who are at ultra-high risk (UHR) for psychosis is well known and moderate cognitive deficits have also been found in UHR. However, the association between smoking and cognition in UHR is unknown and longitudinal studies are lacking.

Method

A cohort study with 330 UHR individuals and 66 controls was conducted, as part of the European network of national schizophrenia networks studying gene–environment interactions (EU-GEI). At baseline and after 6, 12, and 24 months, smoking behavior was assessed with the Composite International Diagnostic Interview and cognitive functioning with a comprehensive test battery. Linear mixed-effects analyses were used to examine the multicross-sectional and prospective associations between (change in) smoking behavior and cognitive functioning, accounting for confounding variables.

Results

At baseline, 53% of UHR and 27% of controls smoked tobacco. Smoking UHR and controls did not significantly differ from nonsmoking counterparts on the tested cognitive domains (speed of processing, attention/vigilance, working memory, verbal learning, or reasoning/problem solving) across different assessment times. Neither smoking cessation nor initiation was associated with a significant change in cognitive functioning in UHR.

Conclusions

No associations were found between smoking and cognitive impairment in UHR nor in controls. However, the fact that one in every two UHR individuals report daily use of tobacco is alarming. Our data suggest that UHR have fewer cognitive impairments and higher smoking cessation rates compared to patients with first-episode psychosis found in literature. Implications to promote smoking cessation in the UHR stage need further investigation.