Background:Patients with psychotic disorders often exhibit premorbid cognitive deficits and future cognitive changes following the onset of illness. This study examined cognitive trajectories in schizophrenia (SCZ), schizoaffective disorder (SZA) and bipolar disorder (BD) compared with healthy matched controls. Method:Cases included individuals with SCZ (n = 24), SZA (n = 15), or BD (n = 11), and 50 controls matched for age, sex, and socioeconomic status (SES). Participants underwent IQ testing at age 17 as part of mandatory military screening (T1); the same tests were administered after illness onset (T2). Results:Participants were assessed approximately 10 years after T1 (SD = 2.6). Cases with SCZ had a non-significant 4-point lower IQ than controls at T1. At T2, SCZ cases showed a 4-point IQ decline, whereas controls demonstrated a 5-point increase, resulting in a significant time × group interaction (F(1, 46) = 12.30, p = .006). At T2 the IQ of cases with SZ was 13 points lower than that of controls (96.97 ± 16.57 vs. 110.19 ± 11.87, respectively; Cohen's d = 0.91; p = .009). A similar trend was observed among cases with SZA and BD, although the magnitude was smaller and the interaction was non-significant. In SCZ, premorbid IQ was positively correlated with years of education (r = 0.670, p < .01), while IQ decline was associated with more psychiatric hospitalizations (r = -0.547, p < .01). Conclusion:SCZ showed cognitive decline relative to controls over time, whereas SZA and BD demonstrated less pronounced cognitive changes. These findings are consistent with both neurodevelopmental and neurodegenerative models of psychotic illness.
Adopting a continuum perspective, this study examined figurative language comprehension in individuals with high or low levels of schizotypy within a non-clinical population. We investigated whether difficulties in figurative language processing are specifically driven by the presence of a competing literal interpretation. We hypothesized that higher schizotypy would be associated with fewer figurative responses and more literal and concrete responses for ambiguous idioms only, with no comparable effect for unambiguous idioms. A total of 377 French-speaking adults from the general population completed an idiom comprehension task and the Schizotypal Personality Questionnaire (SPQ). Based on total SPQ scores, 139 participants were included in the group analyses (73 high schizotypy, 66 low schizotypy). The task combined two methodological approaches previously examined separately by including both ambiguous and unambiguous idioms while distinguishing figurative, literal, and concrete response options. Participants with high schizotypy produced significantly fewer figurative responses and significantly more concrete responses than those with low schizotypy, whereas no difference was observed for literal responses. Importantly, these group differences were found regardless of idiom ambiguity, indicating that they were not specifically driven by the presence of a competing literal interpretation. These findings suggest that reduced figurative interpretations in schizotypy cannot be explained solely by competition from a plausible literal interpretation. More importantly, they highlight that distinguishing literal from concrete response options may help clarify previous inconsistencies in figurative language research in schizotypy and schizophrenia.
We investigated differences in cognitive and social functioning between patients with schizophrenia who met criteria for recovery or remission and healthy controls. This cross-sectional study included 55 patients with schizophrenia who met recovery or remission criteria and 20 healthy controls. Cognitive function was assessed using the Japanese version of the Brief Assessment of Cognition in Schizophrenia (BACS-J), and social function was assessed using the Japanese version of the Social Functioning Scale. Executive function scores did not differ significantly among the three groups; however, the other primary and composite scores of the BACS-J differed significantly among the three groups. In the post hoc analysis, verbal fluency (VF) and attention and processing speed (AP) were higher in the recovery group compared with the remission group (VF: p = 0.043; AP: p = 0.045). All domains of social functioning differed significantly among the three groups. In the post hoc analysis, significant differences between the recovery and remission groups were observed in interpersonal communication (p = 0.002), prosocial activity (p = 0.005), employment/occupation (p < 0.001), and total score (p = 0.005). These results indicate that VF and AP may be important cognitive domains related to clinical recovery in patients with schizophrenia. Furthermore, social functioning domains that require interaction with others may be more important for recovery than daily living skills.
Background:Cognitive symptoms represent a major determinant of long-term disability in chronic schizophrenia and only partially respond to pharmacotherapy. Evidence is growing about the potential effect of cognitive interventions to promote functional recovery. Immersive virtual reality (IVR) offers a simulated, adaptive, and ecologically valid real-world-like scenarios in safe and controlled environments. The present study aimed to evaluate the feasibility, acceptability, and efficacy of IVR-based cognitive rehabilitation in schizophrenia. Methods:We performed a single-blind, randomized, waiting list (WL) controlled trial (Clinicaltrials.gov:NCT07427485). Forty clinically stable outpatients with schizophrenia were allocated (1:1) to IVR or WL. The intervention consisted of 12 weekly IVR-sessions through the CEREBRUM-VR tool. Primary outcome was the change in psychotic symptoms (Positive and Negative Symptoms Scale/PANSS). Secondary outcomes included global functioning (GAF), Digital Symbol Substitution Test (DSST), Animal Naming Test (ANT), Trail-Making Test A (TMT-A). Simple Reaction Choice (SRT) and Choice Reaction Time (CRT) evaluated psychomotor speed. Results:Drop-out rate was 15% per group, attrition rate was 4.9%. Most IVR-assigned participants (77.8%) reported willingness to continue. IVR did not worsen overall or positive psychotic symptoms. A significant IVR between-group improvement emerged for negative symptoms (p < 0.01), psychomotor speed (SRT p = 0.01, CRT p = 0.01), DSST (p = 0.02), and ANT (p = 0.04). GAF and TMT-A changes were nonsignificant. Adverse effects were mostly mild and transient, decreasing over repeated sessions. Conclusion:IVR-based cognitive rehabilitation appears feasible and tolerated in stable outpatients with schizophrenia. Our findings suggest improvement in psychomotor speed and modest improvement in negative symptoms. Larger and longer trials are warranted to confirm clinical relevance.
Background:Cognitive impairment is common in schizophrenia and remains poorly responsive to pharmacological treatment. We examined working-memory change after prefrontal transcranial direct current stimulation (tDCS) across baseline cognitive-severity groups and tested whether baseline severity modified response. Methods:This complete-case secondary analysis included 120 of 173 randomized participants (62 active tDCS, 58 sham) who completed the MATRICS Consensus Cognitive Battery before and after 10 bifrontal tDCS sessions. K-means clustering of seven baseline domain T-scores identified cognitive-severity groups. Treatment effects were assessed using descriptive comparisons and adjusted mixed-effects models. Benjamini-Hochberg correction was applied jointly across 14 domain-by-group hypotheses, with Holm correction as a sensitivity analysis. To address circularity, groups were re-derived without baseline working memory, and moderation was tested using the time × treatment × group interaction. Results:The groups differed mainly in overall cognitive severity rather than profile shape. The active-versus-sham difference in working-memory change was 3.68 T-points (95% CI, 1.57-5.79) in the greater-impairment group and 2.59 T-points (95% CI, 0.90-4.28) in the less-severe-impairment group. Working memory survived joint false-discovery-rate correction in both groups, but Holm correction only in the greater-impairment group. No other domain survived joint correction. After reclustering without baseline working memory, the time × treatment × group interaction was not significant (estimate, 0.93 T-points; 95% CI, -1.71 to 3.56; p = .4915). Conclusions:Prefrontal tDCS showed a working-memory signal across both cognitive-severity groups, but baseline severity did not significantly modify response. The groups should be interpreted as positions along a cognitive-severity continuum rather than distinct profiles or subtypes.
