Profile of cognitive deficits and associations with depressive symptoms and intelligence in chronic early-onset schizophrenia patients

Altered resting-state functional connectivity of the right precuneus and cognition between depressed and non-depressed schizophrenia

The study investigated the resting-state functional connectivity (FC) and cognitive changes in patients with depressed schizophrenia(DS) and non-depressed schizophrenia(NDS). Eighty patients with first-episode schizophrenia and 50 healthy controls (HC) were included to conduct resting-state fMRI. All participants completed MATRICS Consensus Cognitive Battery (MCCB). The right precuneus was selected as the seed in whole-brain FC analysis. Our results showed the cognitive function (All MCCB dimensions) of all schizophrenia patients were worse than HC, but no differences were found between DS and NDS. The DS had decreased FC than NDS between the right precuneus and left middle cingulate gyrus, left cerebellum, right cerebellum. The DS had increased FC than HC between the right precuneus and temporal lobe, occipital lobe, and decreased FC between the right precuneus and left cerebellum. However, the NDS had increased FC than HC between the right precuneus and left cerebellum, right cerebellum, temporal lobe, occipital lobe, left superior parietal lobule. Correlation analysis showed that FC between the right precuneus and occipital lobe was negatively correlated with visual learning in DS and with social cognition in NDS. Our results suggest DS and NDS patients have different patterns of FC, and their FC changes correlate with different domains of cognition.

Do clinical characteristics predict the cognitive course in early-onset schizophrenia-spectrum disorders?

BACKGROUND

Being in a period with extensive brain maturation, adolescents with early-onset schizophrenia-spectrum disorders (EOS) provide unique neurodevelopmental data that may contribute to a better understanding of schizophrenia at all ages. Cognitive dysfunction is a central feature of schizophrenia and is more pronounced in EOS than in later onset illness. However, there is limited research on both the long-term course of global cognition in EOS, and how cognition over time is influenced by clinical characteristics during the early illness period.

METHODS

Thirty-one EOS patients and 73 controls (age 12-18) were assessed on clinical variables at baseline (PANSS, duration of untreated psychosis [DUP], hospitalizations, suicide attempts, and remission). Neuropsychological assessments with the MATRICS Consensus Cognitive Battery (MCCB) were conducted at baseline and after both 1 and 2 years, and composite scores of total performances were calculated. The analyses were performed with a linear mixed model.

RESULTS

The present study found that global cognition followed a stable course over the first years of the disease in EOS, though at a significantly lower level in EOS compared with the controls. We did not detect a relationship between DUP, remission, positive/negative symptoms, and hospitalizations on one hand, and long-term cognition on the other hand, but PANSS-general and suicide attempt history at baseline were identified as risk factors of longitudinal cognitive function.

CONCLUSIONS

Though at different levels, the EOS group and the controls had a similar cognitive course over 2 years. Some baseline characteristics (psychotic symptoms, DUP, remission, and hospitalization) had no influence on cognition within the first 2 years of illness. In contrast, general symptoms and a history of suicide attempts at baseline were more potent risk factors of the cognitive course than the psychotic-specific symptoms, and should, therefore, be subject to specific attention in the evaluation and treatment of patients with early-onset psychosis.

Co-morbid depressive disorder is associated with better neurocognitive performance in first episode schizophrenia spectrum

BACKGROUND

Both major depressive disorder (MDD) and first episode schizophrenia spectrum (FES) are associated with significant neurocognitive deficits. However, it remains unclear whether the neurocognitive deficits in individuals with FES are more severe if there is comorbid depressive disorder. The aim of this study was to compare the neurocognitive profiles between those with and without full-threshold depressive disorder in FES.

METHOD

This study involved secondary analysis of baseline data from a randomized controlled trial of vocational intervention for young people with first-episode psychosis (N = 82; age range: 15-25 years).

RESULTS

Those with full-threshold depressive disorder (n = 24) had significantly better information processing speed than those without full-threshold depressive disorder. Severity of depressive symptoms was also associated with better information processing speed.

LIMITATIONS

In additional to the cross-sectional design, limitations of this study include the absence of assessing insight as a potential mediator.

CONCLUSIONS

After the first psychotic episode, it could be speculated that those with better information processing speed may be more likely to develop full-threshold depressive disorder, as their ability to efficiently process information may allow them to be more aware of their situations and environments, and consequently to have greater insight into the devastating consequences of FES. Such novel findings support the examination of full-threshold depressive disorder in relation to neurocognitive performance across illness phases in future work.