Schizophrenia Research-Cognition最新文献

Objective

Persons with schizophrenia exhibit greater neurocognitive test score dispersion. Here, we seek to characterize dispersion on the Neurocognitive Composite subtests of the Measurement of Treatment Research to Improve Cognition in Schizophrena Consensus Cognitive Battery (MCCB) and determine the relative effects of different antipsychotic formulations on dispersion and mean performance.

Method

In this post hoc analysis of the DREaM study (NCT02431702), which compared treatment with paliperidone palmitate (PP) long-acting injectable with oral antipsychotic (OAP) treatment over 18 months, dispersion in MCCB neurocognitive subtest performance was calculated for each participant by visit (test occasion).

Results

Over 18 months, mean neurocognitive performance improved in a manner consistent with the expected effects of practice in both groups (p < 0.05); this improvement was observed during the first 9 months (PP: p < 0.05, OAP: p < 0.001), followed by stable performance over the second 9 months (PP: p = 0.821, OAP: p = 0.375). Rates of change did not differ between groups (treatment-by-visit interaction: p = 0.548). In contrast, analyses of dispersion focusing on contrasts between baselines and end points of the first and second 9 months revealed different patterns. Over the first 9 months, dispersion in both groups lessened to a similar extent. However, over the second 9 months, dispersion remained stable in the PP group, whereas neurocognitive performance became significantly more variable in the OAP group (p < 0.01).

Conclusion

Dispersion of neurocognitive test scores provides a different index of cognitive change than that provided by composite scores. Long-term maintenance of therapeutic levels provided by PP over time may limit (relative to oral AP) the extent to which cognitive performance becomes more variable.

Cognitive impairments in schizophrenia are well-documented, present across several cognitive domains and found to be relatively stable over time. However, there is a high degree of heterogeneity and indications of domain-specific developmental courses. The present study investigated the 10-year cognitive course in participants with first-episode schizophrenia (FES) and healthy controls on eight cognitive domains and a composite score, looking at group- and individual-level changes.

A total of 75 FES participants and 91 healthy controls underwent cognitive assessment at baseline and follow-up. Linear mixed models were used for group-level analyses and reliable change index (RCI) analyses were used to investigate individual change. The prevalence of clinically significant impairment was explored at both time points, using a cut-off of < −1.5 SD, with significant cognitive impairment defined as impairment on ≥2 domains.

Group-level analyses found main effects of group and time, and time by group interactions. Memory, psychomotor processing speed and verbal fluency improved, while learning, mental processing speed and working memory were stable in both groups. FES participants showed deteriorations in attention and cognitive control. Individual-level analyses mainly indicated stability in both FES and controls, except for a higher prevalence of decline in cognitive control in FES. At baseline, 68.8 % of FES participants had clinically significant impairment, compared to 62.3 % at follow-up.

We mainly found long-term stability and modest increases in cognition over time in FES, as well as a high degree of within-group heterogeneity. We also found indications of deterioration in participants with worse cognitive performance at baseline.

Schizophrenia, a debilitating disorder with typical manifestation of clinical symptoms in early adulthood, is characterized by cognitive impairments in executive processes such as in working memory (WM). However, there is a rare case of individuals with early-onset schizophrenia (EOS) starting before their 18th birthday, while WM and its neural substrates are still undergoing maturation. Using the WM n-back task with functional magnetic resonance imaging, we assessed the functional neurodevelopment of WM in adolescents with EOS and age- and gender-matched typically developing controls. Participants underwent neuroimaging in the same scanner twice, once at age 17 and at 21 (mean interscan interval = 4.3 years). General linear model analysis was performed to explore WM neurodevelopmental changes within and between groups. Psychopathological scores were entered in multiple regressions to detect brain regions whose longitudinal functional change was predicted by baseline symptoms in EOS. WM neurodevelopment was characterized by widespread functional reductions in frontotemporal and cingulate brain areas in patients and controls. No between-group differences were found in the trajectory of WM change. Baseline symptom scores predicted functional neurodevelopmental changes in frontal, cingulate, parietal, occipital, and cerebellar areas. The adolescent brain undergoes developmental processes such as synaptic pruning, which may underlie the refinement WM of network. Prefrontal and parietooccipital activity reduction is affected by clinical presentation of symptoms. Using longitudinal neuroimaging methods in a rare diagnostic sample of patients with EOS may help the advancement of neurodevelopmental biomarkers intended as pharmacological targets to tackle WM impairment.

This study examined social cognitive heterogeneity in Norwegian sample of individuals with schizophrenia (n = 82). They were assessed with three social cognitive tests: Emotion in Biological Motion (emotion processing), Relationships Across Domains (social perception), and Movie for the Assessment of Social Cognition (theory of mind). Hierarchical and k-means cluster analyses using standardized scores on these three tests provided two clusters. The first cluster (68 %) had mild social cognitive impairments (<0.5 standard deviations below healthy comparison participants). The second cluster (32 %) had severe social cognitive impairments (>2 standard deviations below healthy comparison participants). Validity of the two social cognitive subgroups was indicated by significant differences in functioning, symptom load and nonsocial cognition. Our study shows that social cognitive tests can be used for clinical and cognitive subtyping. This is of potential relevance for treatment.

Schizophrenia patients are known to have deficits in contextual vision. However, results are often very mixed. In some paradigms, patients do not take the context into account and, hence, perform more veridically than healthy controls. In other paradigms, context deteriorates performance much more strongly in patients compared to healthy controls. These mixed results may be explained by differences in the paradigms as well as by small or biased samples, given the large heterogeneity of patients' deficits. Here, we show that mixed results may also come from idiosyncrasies of the stimuli used because in variants of the same visual paradigm, tested with the same participants, we found intact and deficient processing.

Objective

Social dysfunction is a major feature of clinical-high-risk states for psychosis (CHR-P). Prior research has identified a neuroanatomical pattern associated with impaired social function outcome in CHR-P. The aim of the current study was to test whether social dysfunction in CHR-P is neurobiologically distinct or in a continuum with the lower end of the normal distribution of individual differences in social functioning.

Methods

We used a machine learning classifier to test for the presence of a previously validated brain structural pattern associated with impaired social outcome in CHR-P (CHR-outcome-neurosignature) in the neuroimaging profiles of individuals from two non-clinical samples (total n = 1763) and examined its association with social function, psychopathology and cognition.

Results

Although the CHR-outcome-neurosignature could be detected in a subset of the non-clinical samples, it was not associated was adverse social outcomes or higher psychopathology levels. However, participants whose neuroanatomical profiles were highly aligned with the CHR-outcome-neurosignature manifested subtle disadvantage in fluid (P_FDR = 0.004) and crystallized intelligence (P_FDR = 0.01), cognitive flexibility (P_FDR = 0.02), inhibitory control (P_FDR = 0.01), working memory (P_FDR = 0.0005), and processing speed (P_FDR = 0.04).

Conclusions

We provide evidence of divergence in brain structural underpinnings of social dysfunction derived from a psychosis-risk enriched population when applied to non-clinical samples. This approach appears promising in identifying brain mechanisms bound to psychosis through comparisons of patient populations to non-clinical samples with the same neuroanatomical profiles.

Studies of patients with schizophrenia and offenders with severe mental disorders decision-making performance have produced mixed findings. In addition, most earlier studies have assessed decision-making skills in offenders or people with mental disorders, separately, thus neglecting the possible additional contribution of a mental disorder on choice patterns in people who offend.

This study aimed to fill this gap by comparing risk-taking in patients with schizophrenia spectrum disorders (SSD), with and without a history of serious violent offending assessing whether, and to what extent, risk-taking represents a significant predictor of group membership, controlling for their executive skills, as well as for socio-demographic and clinical characteristics.

Overall, 115 patients with a primary diagnosis of SSD were recruited: 74 were forensic patients with a lifetime history of severe interpersonal violence and 41 were patients with SSD without such a history. No significant group differences were observed on psychopathological symptoms severity. Forensic generally displayed lower scores than non-forensic patients in all cognitive subtests of the Brief Assessment of Cognition in Schizophrenia (except for the “token motor” and the “digit sequencing” tasks) and on all the six dimensions of the Cambridge Gambling Task, except for “Deliberation time”, in which forensic scored higher than non-forensic patients. “Deliberation time” was also positively, although weakly correlated with “poor impulse control”.

Identifying those facets of impaired decision-making mostly predicting offenders' behaviour among individuals with mental disorder might inform risk assessment and be targeted in treatment and rehabilitation protocols.

Loneliness is common in psychosis and occurs along a continuum. Here we investigate inter-relationships between loneliness, three-dimensional schizotypy, and depressive symptoms before and during the COVID-19 pandemic.

The sample included 507 university students (48.3% participated before and 51.7% during the COVID-19 pandemic) who completed the Multidimensional Schizotypy Scale-Brief, the Counseling Center Assessment of Psychological Symptoms depression scale and the University of California, Los Angeles Loneliness Scale. Schizotypy and depression scores were regressed onto loneliness individually and in multiple regressions.

The cohorts did not differ in any of the schizotypy domains (all p > .29). Depressive symptoms (p = .05) and loneliness (p = .006) were higher during the pandemic than before. Across cohorts, loneliness was significantly associated with positive (β = 0.23, p < .001), negative (β = 0.44, p < .001), and disorganised schizotypy (β = 0.44, p < .001), and with depression (β = 0.72, p < .001). Schizotypy together explained a significant amount of variance in loneliness (R² = 0.26), with significant associations with positive (β = −0.09, p = .047), negative (β = 0.31, p < .001) and disorganised schizotypy (β = 0.34, p < .001). When depression was included (β = 0.69, p < .001), only positive (β = −0.09, p = .008) and negative schizotypy (β = 0.22, p < .001) significantly predicted loneliness.

When all schizotypy dimensions and depression were considered together, only negative schizotypy and depression significantly predicted loneliness. Loneliness and depressive symptoms were higher during the pandemic, but this did not relate to cohort differences in schizotypy.

Background

Psychiatric disorders, especially schizophrenia, are characterised by cognitive impairment. The rapid detection of cognitive dysfunction - also in the course of the disease - is of great importance. The Screen for Cognitive Impairment in Psychiatry (SCIP) was developed to provide screening of psychiatric patients in clinical practice and is available in several languages. Prior psychometric investigations into the dimensionality of the SCIP have produced two different models: a one-factor model assumes that the five subscales of the SCIP load together, whereas an alternative model suggests that the subscales load on two factors, namely verbal memory and processing speed. We carried out a confirmatory factor analysis of the German version of the SCIP (SCIP-G).

Methods

323 patients with psychotic, bipolar affective, and depressive disorders were studied.

Results

The one-factor approach did not yield an acceptable model fit (chi-squared test: χ² = 109.5, df = 5, p < 0.001, χ²/df = 21.9). A two-factor solution, with the subtests Verbal Learning Test-Immediate Recall, Delayed Recall Test of the VLT, and Working Memory Test loading on the first factor, whereas the subtests Verbal Fluency Test and Psychomotor Speed Test loading on the second factor, obtained a good model fit (χ² = 6.7, df = 3, p = 0.08, χ²/df = 2.2).

Conclusions

These data show that a good model fit can be achieved with a two-factor solution for the SCIP. This study is the first to conduct a confirmatory factor analysis using the German SCIP version and to test its dimensional structure using a hypothesis-testing approach.