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Increased brain gyrification in diverse cortical regions has been reported in patients with schizophrenia, possibly reflecting deviations in early neurodevelopment. However, it remains unknown whether patients with schizotypal disorder exhibit similar changes. This magnetic resonance imaging study investigated brain gyrification in 46 patients with schizotypal disorder (29 male, 17 female), 101 patients with schizophrenia (55 male, 46 female), and 77 healthy controls (44 male, 33 female). T1-weighted magnetic resonance images were obtained for each participant. Using FreeSurfer software, the local gyrification index (LGI) of the entire cortex was compared across the groups. Both schizophrenia and schizotypal disorder patients showed a significantly higher LGI in diverse cortical regions, including the bilateral prefrontal and left parietal cortices, as compared with controls, but its extent was broader in schizophrenia especially for the right prefrontal and left occipital regions. No significant correlations were found between the LGI and clinical variables (e.g., symptom severity, medication) for either of the patient groups. Increased LGI in the frontoparietal regions was common to both patient groups and might represent vulnerability to schizophrenia, while more diverse changes in schizophrenia patients might be associated with the manifestation of florid psychosis.

Previous neuroimaging studies of gyrification, a possible marker of early neurodevelopment, in schizophrenia patients have reported inconsistent results. In addition, it remains unclear whether aberrant gyrification in schizophrenia patients, if present, is associated with cognitive impairment, which is one of the core features of schizophrenia. Magnetic resonance images were obtained from 62 patients with first-episode schizophrenia and 57 healthy control subjects. Using FreeSurfer software, local gyrification index (LGI) of the entire cortex was compared between the groups. The relationship between LGI and performance in the Wisconsin Card Sorting Test (WCST) was also examined in a subgroup of patients (n= 28). Compared with the controls, the patients showed a significantly higher LGI in a wide range of bilateral frontal regions as well as in the right inferior parietal and bilateral occipital regions. The number of WCST categories archived in patients was negatively correlated with the LGI mainly in the rostral middle frontal and anterior cingulate regions in the right hemisphere. Our findings suggested a widespread hypergyrification pattern in schizophrenia patients, which supported early neurodevelopmental abnormalities. Our results also suggested that executive dysfunction in schizophrenia patients may be at least partly related to aberrant neurodevelopment, especially in the right frontal regions.

Increased Occipital Gyrification and Development of Psychotic Disorders in Individuals With an At-Risk Mental State: A Multicenter Study

Motor cortex FMRI activation changes in schizophrenia

Identification of the genetically related disorders in the putative schizophrenia spectrum is an unresolved problem. Data from the Finnish Adoptive Family Study of Schizophrenia, which was designed to disentangle genetic and environmental factors influencing risk for schizophrenia, were used to examine clinical phenotypes of schizophrenia spectrum disorders in adopted-away offspring of mothers with schizophrenia spectrum disorders. Subjects were 190 adoptees at broadly defined genetic high risk who had biological mothers with schizophrenia spectrum disorders, including a subgroup of 137 adoptees at narrowly defined high risk whose mothers had DSM-III-R schizophrenia. These high-risk groups, followed to a median age of 44 years, were compared diagnostically with 192 low-risk adoptees whose biological mothers had either a non-schizophrenia-spectrum diagnosis or no lifetime psychiatric diagnosis. In adoptees whose mothers had schizophrenia, the mean lifetime, age-corrected morbid risk for narrowly defined schizophrenia was 5.34% (SE=1.97%), compared to 1.74% (SE=1.00%) for low-risk adoptees, a marginally nonsignificant difference. In adoptees whose mothers had schizophrenia spectrum disorders, the mean age-corrected morbid risk for a schizophrenia spectrum disorder was 22.46% (SE=3.56%), compared with 4.36% (SE=1.51%) for low-risk adoptees, a significant difference. Within the comprehensive array of schizophrenia spectrum disorders, schizotypal personality disorder was found significantly more often in high-risk than in low-risk adoptees. The frequency of the group of nonschizophrenic nonaffective psychoses collectively differentiated high-risk and low-risk adoptees, but the frequencies of the separate disorders within this category did not. The two groups were not differentiated by the prevalence of paranoid personality disorder and of affective disorders with psychotic features. In adopted-away offspring of mothers with schizophrenia spectrum disorders, the genetic liability for schizophrenia-related illness (with the rearing contributions of the biological mothers disentangled) is broadly dispersed. Genetically oriented studies of schizophrenia-related disorders and studies of genotype-environment interaction should consider not only narrowly defined, typical schizophrenia but also schizotypal and schizoid personality disorders and nonschizophrenic nonaffective psychoses.

While diagnostically independent, autism and schizotypal disorders can co-occur. Their concurrent impact on outcomes and phenotypes has not been investigated. We investigated the impact of comorbid autism and schizotypal disorders in children on executive functioning and socio-pragmatic skills - core features of both disorders. Executive functioning (assessed with the Cambridge Neuropsychological Test Automated Battery) and socio-pragmatic skills (assessed using the Melbourne Assessment of Schizotypy in Kids) were investigated in a total of 67 (6-12 year old) children with autism ( n = 15; M/F = 10/5), schizotypal disorder ( n = 8; M/F = 5/3) and comorbid autism and schizotypal disorder ( n = 12; M/F = 5/7) and typically developing children ( n = 32; M/F = 17/15). Both the autism and schizotypal disorder groups performed more poorly than the typically developing group on socio-pragmatic skills and overall performance (i.e. number of stages completed) of the intra-/extra-dimensional set-shifting task (all ps < 0.001). Clear distinctions between the autism and schizotypal groups were present in the intra-/extra-dimensional task relative to the typically developing group - the autism group had difficulties with extra-dimensional shifts ( p < 0.001), and the schizotypal disorder group with intra-dimensional shifts ( p = 0.08). Interestingly, the overall performance of the comorbid group on the intra-/extra-dimensional task was not significantly different from the typically developing group, and they were superior to both the autism ( p = 0.019) and schizotypal disorder ( p = 0.042) groups on socio-pragmatic skills. The phenotypical overlap between autism and schizotypal disorders may be precipitated by different cognitive styles and/or mechanisms associated with attention and information processing. We propose that sustaining and switching attention represent two poles of irregularities across the autism and schizotypal spectra, which appear to converge in a compensatory manner in the comorbid group. Our findings highlight the importance of investigating children with a dual diagnosis of autism and schizotypal disorders, and raise intriguing questions about possible mechanisms to explain the attenuated impairment observed in the group of children with comorbid autism and schizotpyal disorders.

We explored brain volume recovery in terms of cortical thickness (CTh; gyral, sulcal pattern) and surface area (SA), as well as subcortical volume recovery in the first 2 weeks of abstinence in 49 alcohol-dependent patients (ADPs). A widespread reduction of CTh in ADPs at day 1 of abstinence compared to healthy controls, with more pronounced differences in sulci relative to gyri was found. After 2 weeks of abstinence, partial recovery to varying degrees of CTh loss in ADPs was observed for several regions. The longitudinal CTh changes were greater in sulci than in gyri of affected regions. No longitudinal change in SAs and subcortical volumes was found. Alterations of CTh contribute to brain volume loss in alcoholism and recovery during early abstinence. Sulci seem to be more vulnerable to excessive alcohol consumption and to drive abstinence-induced volume recovery. During the initial 2 weeks of abstinence no subcortical volume regain was observed. Either the time span was too short or the lower subcortical volume could represent a predisposing trait marker.

The findings of epidemiological studies suggest that a relationship exists between the risk of schizophrenia and winter births in the Northern Hemisphere, which may affect the process of fetal neurodevelopment. However, it remains unclear whether birth seasons are associated with the brain morphological characteristics of patients within the schizophrenia spectrum. The present magnetic resonance imaging study using FreeSurfer software examined the effects of birth seasons (i.e., summer-born vs. winter-born) on the comprehensive brain surface characteristics of 101 patients with schizophrenia (48 summer- and 53 winter-born), 46 with schizotypal disorder (20 summer- and 26 winter-born), and 76 healthy control subjects (28 summer- and 48 winter-born). In comparisons with summer-born patients, winter-born patients, particularly those with schizophrenia, showed significantly increased gyrification mainly in the left lateral occipital and inferior temporal regions and right fronto-parietal region as well as cortical thinning in the right superior frontal region. Birth seasons did not significantly affect the local gyrification index or cortical thickness in healthy controls. The present whole-brain surface-based analysis demonstrated that brain morphological characteristics reported in the schizophrenia spectrum were more pronounced in winter-born patients than in summer-born patients, suggesting the contribution of early neurodevelopmental factors associated with birth seasons to the pathophysiology of the schizophrenia spectrum.

Reduced auditory segmentation potentials in first-episode schizophrenia

Personnalité schizotypique en milieu universitaire à Marrakech (Maroc)

Working memory (WM) deficits play a prominent role in schizophrenia and have been linked to aberrant frontal-parietal functional connectivity. Schizotypal personality disorder (SPD) is a schizophrenia-spectrum disorder that is biologically related to schizophrenia, but with less marked WM impairment. Comparing network dynamics during WM performance among individuals with schizophrenia-spectrum disorders could enhance our understanding of risk and resilience factors on a spectrum of illness severity. We used dynamiccausalmodeling (DCM) to identify changes in effective connectivity among the lateral-prefrontalcortex (lPFC), anterior-cingulate cortex (ACC) and parietalcortex (PC) associated with WM load during an N-back task in healthy controls (HC; N = 42), individuals with SPD (N = 28), and schizophrenia patients (N = 35). The main findings indicate that N-Back task difficulty (i.e. increasingWM load) significantly modulated connectivity between the ACC and PC, but in different directions depending on diagnostic group. In HC, WM load modulated PC-to-ACC effective connectivity, whereas in schizophrenia, WM load modulated effective connectivity in the opposite direction (i.e. ACC-to-PC). In SPD, no clear directionality emerged between ACC and PC, suggesting an intermediate or mixed pattern of connectivity. In schizophrenia, greater ACC-to-PC connectivity was associated with greater negative and positive symptom severity; a pattern that was also evident in the combined cohort of individuals with SPD and schizophrenia. These findings indicate that the normal pattern of PC-to-ACC effective connectivity modulated by WM load is abnormal in the schizophrenia spectrum which is consistent with abnormalities in processing that instigate early involvement of the ACC for conflict monitoring.

Birth season and gross brain morphology associated with early neurodevelopment in schizophrenia spectrum patients and healthy subjects

BackgroundAccumulating evidence for the co-occurrence Autism spectrum disorder (ASD) and schizotypal personality disorder (SPD) at both the diagnostic and symptom/trait levels raises important questions about the nature of their association and the effect of their co-occurrence on the individual’s phenotype and functional outcome. It has been recommend that informing etiological and phenotypic overlaps between ASD and schizophrenia spectrum disorders (SSD) would require the utilization of a dual-diagnosis cohort compared with two control groups, each singly diagnosed with ASD or SSD, and that the development of a multidimensional model for understanding the relationship between these two spectra would require cohorts to be described not solely by diagnosis, but also by using dimensional measures that cut across diagnostic boundaries. Research comparing adults with ASD and SPD, as well as the impact of their co-occurrence on outcomes is extremely limited. To fill in this gap, we investigated executive functioning in terms of response inhibition and sustained attention, candidate endophenotypes of both conditions, in adults with ASD, SPD, comorbid ASD and SPD, and neurotypical adults using both categorical and dimensional approaches.MethodsA total of 88 adults (Mean Age ± SD = 37.54 ± 10.17): ASD (n = 26; m/f = 20/6); SPD (n = 20; m/f = 14/6); comorbid ASD and SPD (n=9; m/f =6/3) and neurotypicals (n=33; m/f =23/10) completed the Sustained Attention to Response Task (SART) in both its fixed and random forms.Individuals with ASD had a DSM-IV diagnosis of either autism or Asperger Syndrome and met ASD cut-offs on the Autism Diagnostic Observational Schedule-Generic (ADOS-G). All individuals with SPD met DSM-IV criteria for SPD using the Structured Clinical Interview for DSM-IV Axis II Disorders (SCID-II). Individuals in the comorbid group met criteria for both ASD (determined by DSM-IV and the ADOS) and SPD (determined by the SCID-II). In addition, in both the clinical and healthy participants, positive and autistic symptom severity were assessed with the positive subscale of the Positive and Negative Syndrome Scale (PANSSpos) and the PANSS Autism Severity Score (PAUSS), respectively.ResultsControlling for full scale IQ, working memory and medication dosage, group analyses revealed that the comorbid group committed fewer omission errors than the ASD group on the fixed SART, and fewer omission errors than the ASD and SPD groups on the random SART. The individual difference analyses revealed that the PANSSpos and PAUSS interactively reduced omission errors in both the fixed and random SARTs, as well as increased d’ scores, indicative of improved overall performance.DiscussionConcurrent elevated levels of autistic and positive psychotic symptoms seem to be associated with improved sustained attention abilities. We propose that sustaining and switching attention may represent two poles of irregularities across the autism and schizotypal spectra, which appear to converge in a compensatory manner in the comorbid group. Our findings highlight the importance of investigating the concurrent effect of ASD and SPD at both the symptom and diagnostic levels, and the potential benefit of this research approach to understanding the underlying mechanisms of seemingly overlapping phenotypes.

Multimodal classification of drug-naïve first-episode schizophrenia combining anatomical, diffusion and resting state functional resonance imaging

A longitudinal study on intrinsic connectivity of hippocampus associated with positive symptom in first-episode schizophrenia