To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Adverse childhood experiences (ACE) can affect educational attainments, but little is known about their impact on educational achievements in people at clinical high risk of psychosis (CHR).
In total, 344 CHR individuals and 67 healthy controls (HC) were recruited as part of the European Community’s Seventh Framework Programme-funded multicenter study the European Network of National Schizophrenia Networks Studying Gene–Environment Interactions (EU-GEI). The brief version of the Child Trauma Questionnaire was used to measure ACE, while educational attainments were assessed using a semi-structured interview.
At baseline, compared with HC, the CHR group spent less time in education and had higher rates of ACE, lower rates of employment, and lower estimated intelligence quotient (IQ). Across both groups, the total number of ACE was associated with fewer days in education and lower level of education. Emotional abuse was associated with fewer days in education in HC. Emotional neglect was associated with a lower level of education in CHR, while sexual abuse was associated with a lower level of education in HC. In the CHR group, the total number of ACE, physical abuse, and neglect was significantly associated with unemployment, while emotional neglect was associated with employment.
ACE are strongly associated with developmental outcomes such as educational achievement. Early intervention for psychosis programs should aim at integrating specific interventions to support young CHR people in their educational and vocational recovery. More generally, public health and social interventions focused on the prevention of ACE (or reduce their impact if ACE occur) are recommended.
Understanding deviations from typical brain development is a promising approach to comprehend pathophysiology in childhood and adolescence. We investigated if cerebellar volumes different than expected for age and sex could predict psychopathology, executive functions and academic achievement.
Children and adolescents aged 6–17 years from the Brazilian High-Risk Cohort Study for Mental Conditions had their cerebellar volume estimated using Multiple Automatically Generated Templates from T1-weighted images at baseline (n = 677) and at 3-year follow-up (n = 447). Outcomes were assessed using the Child Behavior Checklist and standardized measures of executive functions and school achievement. Models of typically developing cerebellum were based on a subsample not exposed to risk factors and without mental-health conditions (n = 216). Deviations from this model were constructed for the remaining individuals (n = 461) and standardized variation from age and sex trajectory model was used to predict outcomes in cross-sectional, longitudinal and mediation analyses.
Cerebellar volumes higher than expected for age and sex were associated with lower externalizing specific factor and higher executive functions. In a longitudinal analysis, deviations from typical development at baseline predicted inhibitory control at follow-up, and cerebellar deviation changes from baseline to follow-up predicted changes in reading and writing abilities. The association between deviations in cerebellar volume and academic achievement was mediated by inhibitory control.
Deviations in the cerebellar typical development are associated with outcomes in youth that have long-lasting consequences. This study highlights both the potential of typical developing models and the important role of the cerebellum in mental health, cognition and education.
Young people can receive mental health care from many sources, from formal and informal sectors. Caregiver characteristics/experiences/beliefs may influence whether young people get help and the type of care or support used by their child. We investigate facilitators/barriers to receiving formal and/or informal care, particularly those related to the caregiver’s profile.
We interviewed 1,400 Brazilian primary caregivers of young people (aged 10–19), participants of a high-risk cohort. Caregivers reported on young people’s formal/informal mental health care utilization, and associated barriers and facilitators to care. Data were also collected on youth mental health and its impact on everyday life; and caregiver characteristics—education, socioeconomics, ethnicity, mental health, and stigma. Logistic regression models were used to examine the relationship between caregiver and young people characteristics with formal/informal care utilization.
Persistence and greater impact of youth mental health conditions were associated with a higher likelihood of care, more clearly for formal care. Caregiver characteristics, however, also played a key role in whether young people received any care: lower parental stigma was associated with greater formal service use, and lower socioeconomic class showed higher odds of informal care (mainly from religious leaders).
This study highlights the key role of the caregivers as gatekeepers to child treatment access, particularly parental stigma influencing whether young people received any mental health care, even in a low resource setting. These results help to map barriers for treatment access and delivery for young people, aiming to improve intervention efforts and mental health support.
Mental health problems early in life can negatively impact educational attainment, which in turn have negative long-term effects on health, social and economic opportunities. Our aims were to: (i) estimate the impacts of different types of psychiatric conditions on educational outcomes and (ii) to estimate the proportion of adverse educational outcomes which can be attributed to psychiatric conditions.
Participants (N = 2511) were from a school-based community cohort of Brazilian children and adolescents aged 6–14 years enriched for high family risk of psychiatric conditions. We examined the impact of fear- (panic, separation and social anxiety disorder, specific phobia, agoraphobia and anxiety conditions not otherwise specified), distress- (generalised anxiety disorder, major depressive disorder and depressive disorder not otherwise specified, bipolar, obsessive-compulsive, tic, eating and post-traumatic stress disorder) and externalising-related conditions (attention deficit and hyperactivity disorder, conduct and oppositional-defiant conditions) on grade repetition, dropout, age-grade distortion, literacy performance and bullying perpetration, 3 years later. Psychiatric conditions were ascertained by psychiatrists, using the Development and Well-Being Behaviour Assessment. Propensity score and inverse probability weighting were used to adjust for potential confounders, including comorbidity, and sample attrition. We calculated the population attributable risk percentages to estimate the proportion of adverse educational outcomes in the population which could be attributed to psychiatric conditions. Analyses were conducted separately for males and females.
Fear and distress conditions in males were associated with school dropout (odds ratio (OR) = 2.76; 95% confidence interval (CI) = 1.06, 7.22; p < 0.05) and grade repetition (OR = 2.76; 95% CI = 1.32, 5.78; p < 0.01), respectively. Externalising conditions were associated with grade repetition in males (OR = 1.66; 95% CI = 1.05, 2.64; p < 0.05) and females (OR = 2.03; 95% CI = 1.15, 3.58; p < 0.05), as well as age-grade distortion in males (OR = 1.66; 95% CI = 1.05, 2.62; p < 0.05) and females (OR = 2.88; 95% CI = 1.61, 5.14; p < 0.001). Externalising conditions were also associated with lower literacy levels (β = −0.23; 95% CI = −0.34, −0.12; p < 0.001) and bullying perpetration (OR = 3.12; 95% CI = 1.50, 6.51; p < 0.001) in females. If all externalising conditions were prevented or treated, we estimate that 5.0 and 4.8% of grade repetition would not have occurred in females and males, respectively, as well as 10.2 (females) and 5.3% (males) of age-grade distortion cases and 11.4% of female bullying perpetration.
The study provides evidence of the negative impact of psychiatric conditions on educational outcomes in a large Brazilian cohort. Externalising conditions had the broadest and most robust negative impacts on education and these were particularly harmful to females which are likely to limit future socio-economic opportunities.
Cognition heavily relies on social determinants and genetic background. Latin America comprises approximately 8% of the global population and faces unique challenges, many derived from specific demographic and socioeconomic variables, such as violence and inequality. While such factors have been described to influence mental health outcomes, no large-scale studies with Latin American population have been carried out. Therefore, we aim to describe the cognitive performance of a representative sample of Latin American individuals with schizophrenia and its relationship to clinical factors. Additionally, we aim to investigate how socioeconomic status (SES) relates to cognitive performance in patients and controls.
We included 1175 participants from five Latin American countries (Argentina, Brazil, Chile, Colombia, and Mexico): 864 individuals with schizophrenia and 311 unaffected subjects. All participants were part of projects that included cognitive evaluation with MATRICS Consensus Cognitive Battery and clinical assessments.
Patients showed worse cognitive performance than controls across all domains. Age and diagnosis were independent predictors, indicating similar trajectories of cognitive aging for both patients and controls. The SES factors of education, parental education, and income were more related to cognition in patients than in controls. Cognition was also influenced by symptomatology.
Patients did not show evidence of accelerated cognitive aging; however, they were most impacted by a lower SES suggestive of deprived environment than controls. These findings highlight the vulnerability of cognitive capacity in individuals with psychosis in face of demographic and socioeconomic factors in low- and middle-income countries.
Psychosis is associated with a reasoning bias, which manifests as a tendency to ‘jump to conclusions’. We examined this bias in people at clinical high-risk for psychosis (CHR) and investigated its relationship with their clinical outcomes.
In total, 303 CHR subjects and 57 healthy controls (HC) were included. Both groups were assessed at baseline, and after 1 and 2 years. A ‘beads’ task was used to assess reasoning bias. Symptoms and level of functioning were assessed using the Comprehensive Assessment of At-Risk Mental States scale (CAARMS) and the Global Assessment of Functioning (GAF), respectively. During follow up, 58 (16.1%) of the CHR group developed psychosis (CHR-T), and 245 did not (CHR-NT). Logistic regressions, multilevel mixed models, and Cox regression were used to analyse the relationship between reasoning bias and transition to psychosis and level of functioning, at each time point.
There was no association between reasoning bias at baseline and the subsequent onset of psychosis. However, when assessed after the transition to psychosis, CHR-T participants showed a greater tendency to jump to conclusions than CHR-NT and HC participants (55, 17, 17%; χ2 = 8.13, p = 0.012). There was a significant association between jumping to conclusions (JTC) at baseline and a reduced level of functioning at 2-year follow-up in the CHR group after adjusting for transition, gender, ethnicity, age, and IQ.
In CHR participants, JTC at baseline was associated with adverse functioning at the follow-up. Interventions designed to improve JTC could be beneficial in the CHR population.
Social and environmental factors such as poverty or violence modulate the risk and course of schizophrenia. However, how they affect the brain in patients with psychosis remains unclear.
We studied how environmental factors are related to brain structure in patients with schizophrenia and controls in Latin America, where these factors are large and unequally distributed.
This is a multicentre study of magnetic resonance imaging in patients with schizophrenia and controls from six Latin American cities. Total and voxel-level grey matter volumes, and their relationship with neighbourhood characteristics such as average income and homicide rates, were analysed with a general linear model.
A total of 334 patients with schizophrenia and 262 controls were included. Income was differentially related to total grey matter volume in both groups (P = 0.006). Controls showed a positive correlation between total grey matter volume and income (R = 0.14, P = 0.02). Surprisingly, this relationship was not present in patients with schizophrenia (R = −0.076, P = 0.17). Voxel-level analysis confirmed that this interaction was widespread across the cortex. After adjusting for global brain changes, income was positively related to prefrontal cortex volumes only in controls. Conversely, the hippocampus in patients with schizophrenia, but not in controls, was relatively larger in affluent environments. There was no significant correlation between environmental violence and brain structure.
Our results highlight the interplay between environment, particularly poverty, and individual characteristics in psychosis. This is particularly important for harsh environments such as low- and middle-income countries, where potentially less brain vulnerability (less grey matter loss) is sufficient to become unwell in adverse (poor) environments.
Resistance to antipsychotic treatment affects up to 30% of patients with schizophrenia. Although the time course of development of treatment-resistant schizophrenia (TRS) varies from patient to patient, the reasons for these variations remain unknown. Growing evidence suggests brain dysconnectivity as a significant feature of schizophrenia. In this study, we compared fractional anisotropy (FA) of brain white matter between TRS and non–treatment-resistant schizophrenia (non-TRS) patients. Our central hypothesis was that TRS is associated with reduced FA values.
TRS was defined as the persistence of moderate to severe symptoms after adequate treatment with at least two antipsychotics from different classes. Diffusion-tensor brain MRI obtained images from 34 TRS participants and 51 non-TRS. Whole-brain analysis of FA and axial, radial, and mean diffusivity were performed using Tract-Based Spatial Statistics (TBSS) and FMRIB’s Software Library (FSL), yielding a contrast between TRS and non-TRS patients, corrected for multiple comparisons using family-wise error (FWE) < 0.05.
We found a significant reduction in FA in the splenium of corpus callosum (CC) in TRS when compared to non-TRS. The antipsychotic dose did not relate to the splenium CC.
Our results suggest that the focal abnormality of CC may be a potential biomarker of TRS.
Sex differences in cognitive functioning have long been recognized in schizophrenia patients and healthy controls (HC). However, few studies have focused on patients with an at-risk mental state (ARMS) for psychosis. Thus, the aim of the present study was to investigate sex differences in neurocognitive performance in ARMS patients compared with HC.
The data analyzed in this study were collected within the multicenter European Gene–Environment Interactions study (11 centers). A total of 343 ARMS patients (158 women) and 67 HC subjects (33 women) were included. All participants completed a comprehensive neurocognitive battery. Linear mixed effects models were used to explore whether sex differences in cognitive functioning were present in the total group (main effect of sex) and whether sex differences were different for HC and ARMS (interaction between sex and group).
Women performed better in social cognition, speed of processing, and verbal learning than men regardless of whether they were ARMS or HC. However, only differences in speed of processing and verbal learning remained significant after correction for multiple testing. Additionally, ARMS patients displayed alterations in attention, current IQ, speed of processing, verbal learning, and working memory compared with HC.
Findings indicate that sex differences in cognitive functioning in ARMS are similar to those seen between healthy men and women. Thus, it appears that sex differences in cognitive performance may not be specific for ARMS, a finding resembling that in patients with schizophrenic psychoses.
Mental disorders can have a major impact on brain development. Peripheral blood concentrations of brain-derived neurotrophic factor (BDNF) are lower in adult psychiatric disorders. Serum BDNF concentrations and BDNF genotype have been associated with cortical maturation in children and adolescents. In 2 large independent samples, this study tests associations between serum BDNF concentrations, brain structure, and psychopathology, and the effects of BDNF genotype on BDNF serum concentrations in late childhood and early adolescence.
Children and adolescents (7-14 years old) from 2 cities (n = 267 in Porto Alegre; n = 273 in São Paulo) were evaluated as part of the Brazilian high-risk cohort (HRC) study. Serum BDNF concentrations were quantified by sandwich ELISA. Genotyping was conducted from blood or saliva samples using the SNParray Infinium HumanCore Array BeadChip. Subcortical volumes and cortical thickness were quantified using FreeSurfer. The Development and Well-Being Behavior Assessment was used to identify the presence of a psychiatric disorder.
Serum BDNF concentrations were not associated with subcortical volumes or with cortical thickness. Serum BDNF concentration did not differ between participants with and without mental disorders, or between Val homozygotes and Met carriers.
No evidence was found to support serum BDNF concentrations as a useful marker of developmental differences in brain and behavior in early life. Negative findings were replicated in 2 of the largest independent samples investigated to date.
Previous work showed traumatic life events (TLE) with intention to harm, like bullying and abuse, to be more strongly associated with psychotic experiences (PE) than other types of trauma, like accidents. However, this association is subject to reporting bias and can be confounded by demographic characteristics and by differences in dose of exposure across different trauma categories. We studied the association between TLE with and without intention to harm and PE, taking into account potential confounders and biases.
A total of 2245 children and adolescents aged 6–14 years were interviewed by psychologists. The interview included the presence of 20 PE (both self-report and psychologist evaluation). In addition, parents provided information on child exposure to trauma, mental health and PE.
Results showed no significant association between TLE without intention to harm only and PE for the three methods of assessment of PE (self-report, parent report and psychologist rating). On the other hand, there was a positive association between PE and TLE in groups exposed to traumatic experiences with intention to harm (with intention to harm only and with and without intention to harm). Results remained significant after controlling for demographic and clinical confounders, but this positive association was no longer significant after adjusting for the number of TLE.
TLE with intention to harm display a stronger association with PE than TLE without intention to harm, and this difference is likely reducible to a greater level of traumatic exposure associated with TLE with intention to harm.
According to the experience of people with schizophrenia, their psychiatrists' attitude towards the outcome of their illness is lacking in hope, which directly affects mutual faith in treatment. Here we discuss the scientific basis of hope and show its instrumental role in optimising the best treatment strategies for schizophrenia.
Declaration of interest
R.A.B has received honoraria for educational input and non-financial support from Ache; honoraria for educational input from Lundbeck; grants, honoraria for educational input and non-financial support from Janssen; all outside the submitted work. G.E.M.G. has received honoraria for educational input and non-financial support from Janssen outside the submitted work. G.M. reports support from Janssen-Cilag, outside the submitted work, and is an employee at Janssen-Cilag. S.S. has received grants and honoraria for educational input from EnVivo Pharmaceuticals, Takeda, AbbVie and Janssen Pharmaceuticals, outside the submitted work.
Oxidative stress has been documented in chronic schizophrenia and in the first episode of psychosis, but there are very little data on oxidative stress prior to the disease onset.
This work aimed to compare serum levels of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in young individuals at ultra-high risk (UHR) of developing psychosis with a comparison healthy control group (HC).
Thirteen UHR subjects and 29 age- and sex-matched healthy controls (HC) were enrolled in this study. Clinical assessment included the Comprehensive Assessment of At-Risk Mental States (CAARMS), the Semi-Structured Clinical Interview for DSM-IV Axis-I (SCID-I) or the Kiddie-SADS-Present and Lifetime Version (K-SADS-PL), and the Global Assessment of Functioning (GAF) scale. Activities of SOD and GPx were measured in serum by the spectrophotometric method using enzyme-linked immunosorbent assay kits.
After adjusting for age and years of education, there was a significant lower activity of SOD and lower GPX activity in the UHR group compared to the healthy control group (rate ratio [RR]=0.330, 95% CI 0.187; 0.584, p<0.001 and RR=0.509, 95% CI 0.323; 0.803, p=0.004, respectively). There were also positive correlations between GAF functioning scores and GPx and SOD activities.
Our results suggest that oxidative imbalances could be present prior to the onset of full-blown psychosis, including in at-risk stages. Future studies should replicate and expand these results.
Several studies have shown cortical volume loss in frontotemporal regions in schizophrenia patients, and it is known that these reductions may be associated with disease symptoms and cognitive deficits. The aim of this study was to investigate possible cortical thickness correlations in frontotemporal regions in relation to age at onset and duration of illness.
One hundred forty-eight schizophrenia patients (97 males; age and SD 36.30 ± 10.06) and 87 (57 males; age and SD 36.48 ± 10.10) age-matched healthy subjects underwent a brain MRI scan. Cortical segmentation and surface statistical analysis were performed using the FreeSurfer software package. Results were corrected for multiple comparisons using the Monte Carlo method considering a cluster-corrected Type I Error of 5%.
Compared to controls, schizophrenia patients presented significant cortical thinning in the frontotemporal, parietal, and occipital cortices. No correlation between prefrontal cortex thickness and duration of illness in patients with schizophrenia or between frontotemporal cortical thickness and age at onset was found. However, a significant interaction between age and diagnosis was observed on frontal cortical thickness with patients presenting a thinner cortex than expected for age.
Although there was no correlation between age of onset and duration of illness with brain volume, our findings suggest that there is an accelerated cortical loss in schizophrenia, thus reinforcing the progressive processes of the disease.
Many studies have suggested that adolescence is a period of particular
vulnerability to neurocognitive effects associated with substance misuse.
However, few large studies have measured differences in cognitive
performance between chronic cannabis users who started in early
adolescence (before age 15) with those who started later.
To examine the executive functioning of individuals who started chronic
cannabis use before age 15 compared with those who started chronic
cannabis use after 15 and controls.
We evaluated the performance of 104 chronic cannabis users (49
early-onset users and 55 late-onset users) and 44 controls who undertook
neuropsychological tasks, with a focus on executive functioning.
Comparisons involving neuropsychological measures were performed using
generalised linear model analysis of variance (ANOVA).
The early-onset group showed significantly poorer performance compared
with the controls and the late-onset group on tasks assessing sustained
attention, impulse control and executive functioning.
Early-onset chronic cannabis users exhibited poorer cognitive performance
than controls and late-onset users in executive functioning. Chronic
cannabis use, when started before age 15, may have more deleterious
effects on neurocognitive functioning.
Previous work has suggested that decrement in both processing speed and working memory span plays a role in the memory impairment observed in patients with schizophrenia. We undertook a study to examine simultaneously the effect of these two factors. A sample of 49 patients with schizophrenia and 43 healthy controls underwent a battery of verbal and visual memory tasks. Superficial and deep encoding memory measures were tallied. We conducted regression analyses on the various memory measures, using processing speed and working memory span as independent variables. In the patient group, processing speed was a significant predictor of superficial and deep memory measures in verbal and visual memory. Working memory span was an additional significant predictor of the deep memory measures only. Regression analyses involving all participants revealed that the effect of diagnosis on all the deep encoding memory measures was reduced to non-significance when processing speed was entered in the regression. Decreased processing speed is involved in verbal and visual memory deficit in patients, whether the task require superficial or deep encoding. Working memory is involved only insofar as the task requires a certain amount of effort. (JINS, 2011, 17, 485–493)
Previous studies have revealed semantic memory impairments in patients with schizophrenia, and suggested that certain of these impairments were related to thought disorganization. One explanation offered for this is a broadening of the boundaries of semantic categories in schizophrenia. We selected 16 semantic categories, and required a sample of 41 schizophrenia patients and 43 healthy control subjects to produce one exemplar from each category. The typicality of the subjects’ responses was rated. The exemplars produced by the patients were on average less typical than those produced by the healthy controls. No significant association between typicality of the response and thought disorganization was revealed in the patient sample. Affective flattening, alogia, and anhedonia were significantly and inversely associated with the typicality score, that is, higher ratings of these symptoms were associated with more typical responses. Our results suggest that a broadening of semantic category boundaries is observed in patients with schizophrenia, but is unrelated to thought disorganization. This semantic abnormality is not a feature of the patients with high ratings of certain negative symptoms. (JINS, 2010, 16, 822–828.)