Association of depressive symptoms with cognitive impairment in patients with never-treated first-episode schizophrenia: Analysis of the Depression in Schizophrenia in China (DISC) study

Conceptualization and characterization of "primary" and "secondary" cognitive impairment in schizophrenia

Cognitive impairment represents one of the core features of schizophrenia, involves both neurocognition and social cognition domains, and has a significant negative impact on real-world functioning. The present review provides a framework for the conceptualization and characterization of "primary" and "secondary" cognitive impairment in schizophrenia. In this conceptualization, primary cognitive impairment can be defined as a consequence of the neurobiological alterations that underlie psychopathological manifestations of the disorder, while secondary cognitive impairment can be defined as the results of a source issue that has a negative impact on cognitive performance. Sources of secondary cognitive impairment are frequent in people with schizophrenia and include several different factors, such as positive and negative symptoms, depressive symptoms, autistic symptoms, pharmacotherapy, substance abuse, metabolic syndrome, social deprivation, and sleep disorders. It can be hypothesized that secondary cognitive impairment may be improved by effectively resolving the source issue, while primary cognitive impairment may benefit from dedicated treatment. Further research is required to confirm this hypothesis, to better characterize the distinction between primary and secondary cognitive impairment in a clinical and in a neurobiological perspective, and to evaluate the impact of systematically assessing and treating secondary cognitive impairment.

Association between treatment resistance and cognitive function in schizophrenia

INTRODUCTION

Treatment-resistant schizophrenia (TRS) affects around 30% of individuals with schizophrenia. About half of the patients with TRS who are treated with clozapine do not show a meaningful clinical response, that is, clozapine resistance. To date, the relationship between cognitive function and treatment response categories is not entirely clear. This study evaluated the cognitive performance across subgroups stratified by treatment response, and we hypothesised that cognitive impairment increases with increased treatment resistance.

METHODS

This study was conducted at the Institute of Mental Health, Singapore, and included healthy controls and people with schizophrenia categorised into these groups: antipsychotic-responsive schizophrenia (ARS), clozapine-responsive TRS (TRS-CR) and clozapine-resistant TRS (ultra-treatment-resistant schizophrenia [UTRS]). Cognitive function was assessed using the Brief Assessment of Cognition-Short Form. Symptoms were measured with the Positive and Negative Syndrome Scale (PANSS). The planned statistical analyses included adjustments for covariates such as age, sex, PANSS scores and antipsychotic dose, which might affect cognitive function.

RESULTS

There were significant differences in overall cognitive performance between the groups: ARS had the least impairment, followed by TRS-CR and UTRS. Antipsychotic dose, and PANSS negative and disorganisation/cognitive factors were significant predictors of overall cognitive function in all patient groups.

CONCLUSIONS

Our study found differences in cognitive function that aligned with levels of treatment resistance: the greater the degree of treatment resistance, the poorer the cognitive function. Interventions to improve negative and disorganisation symptoms might be effective to enhance the cognitive function and treatment outcomes in schizophrenia.

Study on correlations of BDNF, PI3K, AKT and CREB levels with depressive emotion and impulsive behaviors in drug-naïve patients with first-episode schizophrenia

BACKGROUND

The pathogenesis of schizophrenia is still unknown. Nearly a half of schizophrenic patients have depressive symptoms and even some impulsive behaviors. The definite diagnosis of schizophrenia is an immense challenge. Molecular biology plays an essential role in the research on the pathogenesis of schizophrenia.

OBJECTIVE

This study aims to analyze the correlations of serum protein factor levels with depressive emotion and impulsive behaviors in drug-naïve patients with first-episode schizophrenia.

METHODS

Seventy drug-naïve patients with first-episode schizophrenia and sixty-nine healthy volunteers from the health check center in the same period participated in this study. In both the patient group and control group, brain-derived neurotrophic factor (BDNF), phosphatidylin-ositol-3-kinase (PI3K), protein kinase B (AKT), and cAMP-response element binding protein (CREB) levels in the peripheral blood were tested by enzyme-linked immunosorbent assay (ELISA). The depressive emotion and impulsive behaviors were evaluated with Chinese versions of the Calgary Depression Scale for Schizophrenia (CDSS) and Short UPPS-P Impulsive Behavior Scale (S-UPPS-P), respectively.

RESULTS

The serum levels of BDNF, PI3K, and CREB in the patient group were lower than those in the control group, while AKT level, total CDSS score and total S-UPPS-P score were all higher. In the patient group, total CDSS score, and total S-UPPS-P score were both correlated negatively with BDNF, PI3K, and CREB levels but positively with AKT level, and the lack-of-premeditation (PR) sub-scale score was not significantly correlated with BDNF, PI3K, AKT, and CREB levels.

CONCLUSION

Our study results showed that the peripheral blood levels of BDNF, PI3K, AKT, and CREB in drug-naïve patients with first-episode schizophrenia were significantly different from those in the control group. The levels of these serum protein factors are promising biomarkers to predict schizophrenic depression and impulsive behaviors.

Rumination mediates the relationship between childhood trauma and depressive symptoms in schizophrenia patients

Rumination and childhood trauma are related to depressive symptoms in clinical and non-clinical individuals. This is the first study aimed to test the mediating effect of rumination on the relationship between childhood trauma and depressive symptoms in schizophrenia patients. A total of 313 schizophrenia patients were recruited in the present study. The 17-item Hamilton Depression Rating Scale (HAMD-17) was adopted to evaluate depressive symptoms, the short-form Childhood Trauma Questionnaire (CTQ-SF) and the 10-item Ruminative response scale (RRS-10) were utilized to assess the childhood trauma and rumination in patients, respectively. Our results showed that 168 schizophrenia patients (53.67%) had comorbid depressive symptoms. These patients with depressive symptoms had higher levels of childhood trauma [both CTQ-SF total scores and emotional abuse (EA), emotional neglect (EN), physical neglect (PN) subscale scores] and rumination (both RRS-10 total scores and brooding, reflection subscale scores) compared to patients without depressive symptoms. The stepwise logistic regression analysis identified that EN (OR 1.196, P = 0.003), PN (OR 1.1294, P < 0.001), brooding (OR 1.291, P < 0.001) and reflection (OR 1.481, P < 0.001) could independently predict the depressive symptoms in schizophrenia patients. Moreover, RRS-10 and its subscale scores could mediate the relationship between depressive symptoms and childhood trauma, especially EA, EN and PN in schizophrenia. Our preliminary findings suggest that the rigorous assessment and psychosocial interventions of rumination are important to alleviate the influence of childhood trauma on depressive symptoms in schizophrenia patients.

Anxious-depressive symptoms after a first episode of schizophrenia: Response to treatment and psychopathological considerations from the 2-year "Parma Early Psychosis" program

Depression is common in schizophrenia and is correlated with suicide risk and poor long-term outcomes. However, the presence of depressive symptoms is often underestimated in both research and treatment, particularly at the illness onset. The goals of this study were: (a) to longitudinally observe anxious-depressive symptom levels in patients with First Episode Schizophrenia (FES) during a 24 months of follow-up period, and (b) to examine their associations with other psychopathology and the intervention patients received in an "Early Intervention in Psychosis" (EIP) program during the follow-up period. The Global Assessment of Functioning (GAF) and the Positive And Negative Syndrome Scale (PANSS) were completed by 159 FES patients both at baseline and across the follow-up. Data were analyzed by linear regression analysis and Spearman's coefficients. Anxious-depressive symptoms had significant longitudinal associations with GAF deterioration and PANSS "Positive Symptoms", "Negative Symptoms" and "Disorganization" subscores. During the follow-up period, FES participants significantly improved the level of anxious-depressive symptoms. This was significantly associated with the number of case management and individual psychotherapy meetings the patient engaged in, as well as with lower antipsychotic doses prescribed during the follow-up period. In conclusion, anxious-depressive symptoms are prominent in FES and at the initial entry into EIP programs. Anxious-depressive symptom severity tends to diminish overtime, especially with the provision of specialized EIP treatments. However, since we did not have a control population studied in parallel, we cannot say whether these results are specific to the protocols of EIP programs or just to the intensity of engagement in care.