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 email@example.com
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.
Previous meta-analyses have shown that almost all antipsychotics are associated with weight gain. However, mean weight gain is not informative about clinically relevant weight gain or weight loss.
To provide further insight into the more severe body weight changes associated with antipsychotic use, we assessed the proportion of patients with clinically relevant weight gain (CRWG) and clinically relevant weight loss (CRWL), defined as ≥7% weight gain and ≥7% weight loss.
We searched PubMed, Embase and PsycInfo for randomised controlled trials of antipsychotics that reported CRWG and CRWL in study populations aged 15 years or older. We conducted meta-analyses stratified by antipsychotic and study duration using a random-effects model. We performed meta-regression analyses to assess antipsychotic-naive status and psychiatric diagnosis as modifiers for CRWG. PROSPERO: CRD42020204734.
We included 202 articles (201 studies). Almost all included antipsychotics were associated with CRWG. For CRWL, available data were too limited to draw firm conclusions. For some antipsychotics, CRWG was more pronounced in individuals who were antipsychotic-naive than in individuals switching to another antipsychotic. Moreover, a longer duration of antipsychotic use was associated with more CRWG, but not CRWL. For some antipsychotics, CRWG was higher in people diagnosed with schizophrenia, but this was inconsistent.
Switching antipsychotic medication is associated with both weight gain and weight loss, but the level of CRWG is higher than CRWL in antipsychotic-switch studies. CRWG was more pronounced in antipsychotic-naive patients, highlighting their vulnerability to weight gain. The impact of diagnosis on CRWG remains inconclusive.
Women with triple X syndrome (TXS) have an extra X chromosome. TXS appeared to be associated with psychiatric disorders in biased or underpowered studies.
This study aims to describe the prevalence of psychiatric disorders in adults with TXS in a relatively large and less biased group of participants.
In this cross-sectional study, data were collected from 34 women with TXS (mean age = 32.9; s.d. = 13.1) and 31 controls (mean age = 34.9; s.d. = 13.7). Psychiatric disorders were assessed using the MINI International Neuropsychiatric Interview (MINI) and the adult behavior checklist (ABCL). Trait and state anxiety were assessed using the State–Trait Anxiety Inventory.
In the TXS group, MINI results showed a higher prevalence of major depressive episodes (43.3%), psychotic disorders (29.4%), and suicidality (23.5%). Only 50% of the TXS group earned a normal score for the total syndrome score using the ABCL. In addition, levels of trait anxiety were higher in the TXS group. Only three women in each group received psychotropic medication. Impaired social functioning appeared to represent a major risk factor in TXS as regards psychotic, affective disorders, trait anxiety, and low self-esteem.
Women with TXS are vulnerable to developing psychiatric disorders, and women with both TXS and impaired social functioning are even more vulnerable.
22q11.2 deletion syndrome (22q11.2DS) is associated with an elevated genetic risk of several psychiatric disorders. However, the prevalence of post-traumatic stress disorder (PTSD) in individuals with 22q11.2DS has been reported to be only 0.9%; this is lower than that of the general population (3.9%). We explored the occurrence of PTSD and traumatic events in a Dutch cohort of 112 adults with 22q11.2DS, and found PTSD in 8.0%, traumatic events in 20.5% and trauma-focused treatment in 17.9% of patients. Our novel findings suggest that PTSD may be underdiagnosed in individuals with 22q11.2DS. Clinicians and other caregivers should be alert to trauma in this population in order to enable treatment and minimise psychiatric burden.
Cognitive deficits may be characteristic for only a subgroup of first-episode psychosis (FEP) and the link with clinical and functional outcomes is less profound than previously thought. This study aimed to identify cognitive subgroups in a large sample of FEP using a clustering approach with healthy controls as a reference group, subsequently linking cognitive subgroups to clinical and functional outcomes.
204 FEP patients were included. Hierarchical cluster analysis was performed using baseline brief assessment of cognition in schizophrenia (BACS). Cognitive subgroups were compared to 40 controls and linked to longitudinal clinical and functional outcomes (PANSS, GAF, self-reported WHODAS 2.0) up to 12-month follow-up.
Three distinct cognitive clusters emerged: relative to controls, we found one cluster with preserved cognition (n = 76), one moderately impaired cluster (n = 74) and one severely impaired cluster (n = 54). Patients with severely impaired cognition had more severe clinical symptoms at baseline, 6- and 12-month follow-up as compared to patients with preserved cognition. General functioning (GAF) in the severely impaired cluster was significantly lower than in those with preserved cognition at baseline and showed trend-level effects at 6- and 12-month follow-up. No significant differences in self-reported functional outcome (WHODAS 2.0) were present.
Current results demonstrate the existence of three distinct cognitive subgroups, corresponding with clinical outcome at baseline, 6- and 12-month follow-up. Importantly, the cognitively preserved subgroup was larger than the severely impaired group. Early identification of discrete cognitive profiles can offer valuable information about the clinical outcome but may not be relevant in predicting self-reported functional outcomes.
Neuroticism is associated with increased stress reactivity. In autism spectrum disorders (ASD), emotional stress reactivity is increased and there is some evidence for an increased negative affect (NA) when with less familiar people. The aim of this study was to compare adults with ASD and controls on levels of neuroticism and on interactions between neuroticism and appraised stress or social context in models of NA. This is a cross-sectional observational study comprising a group of 50 adults with ASD and 51 controls. Experience sampling method (ESM) reports were collected for 10 days to measure daily life stress, mood, and social context. Multilevel regression analyses revealed significantly higher neuroticism levels in ASD than in controls. Adults with ASD who scored high on neuroticism showed a significantly stronger association between activity/social stress and NA (i.e., higher stress reactivity) than those with low scores. Furthermore, the association between neuroticism and NA was stronger when adults with ASD were with less familiar people compared with being alone or with familiar people. No consistent corresponding significant interactions were found in the control group. In conclusion, in ASD, neuroticism moderates the association between appraised stress and NA as well as the association between social context and NA.
Triple X syndrome (TXS) is caused by aneuploidy of the X chromosome and is associated with impaired social functioning in children; however, its effect on social functioning and emotion recognition in adults is poorly understood.
The aim of this study was to investigate social functioning and emotion recognition in adults with TXS.
This cross-sectional cohort study was designed to compare social functioning and emotion recognition between adults with TXS (n = 34) and an age-matched control group (n = 31). Social functioning was assessed with the Adult Behavior Checklist and Social Responsiveness Scale for Adults. Emotion recognition was assessed with the Emotion Recognition Task in the Cambridge Neuropsychological Test Automated Battery. Differences were analysed by Mann-Whitney U-test.
Compared with controls, women with TXS scored higher on the Adult Behavior Checklist, including the Withdrawn scale (P < 0.001, effect size 0.4) and Thought Problems scale (P < 0.001, effect size 0.4); and higher on the Social Responsiveness Scale for Adults, indicating impaired social functioning (P < 0.001, effect size 0.5). In addition, women with TXS performed worse on the Emotion Recognition Task, particularly with respect to recognising sadness (P < 0.005, effect size 0.4), fear (P < 0.01, effect size 0.4) and disgust (P < 0.02, effect size 0.3).
Our findings indicate that adults with TXS have a higher prevalence of impaired social functioning and emotion recognition. These results highlight the relevance of sex chromosome aneuploidy as a potential model for studying disorders characterised by social impairments such as autism spectrum disorder, particularly among women.
The prevalence of psychotic experiences (PEs) is higher in low-and-middle-income-countries (LAMIC) than in high-income countries (HIC). Here, we examine whether this effect is explicable by measurement bias.
A community sample from 13 countries (N = 7141) was used to examine the measurement invariance (MI) of a frequently used self-report measure of PEs, the Community Assessment of Psychic Experiences (CAPE), in LAMIC (n = 2472) and HIC (n = 4669). The CAPE measures positive (e.g. hallucinations), negative (e.g. avolition) and depressive symptoms. MI analyses were conducted with multiple-group confirmatory factor analyses.
MI analyses showed similarities in the structure and understanding of the CAPE factors between LAMIC and HIC. Partial scalar invariance was found, allowing for latent score comparisons. Residual invariance was not found, indicating that sum score comparisons are biased. A comparison of latent scores before and after MI adjustment showed both overestimation (e.g. avolition, d = 0.03 into d = −0.42) and underestimation (e.g. magical thinking, d = −0.03 into d = 0.33) of PE in LAMIC relative to HIC. After adjusting the CAPE for MI, participants from LAMIC reported significantly higher levels on most CAPE factors but a significantly lower level of avolition.
Previous studies using sum scores to compare differences across countries are likely to be biased. The direction of the bias involves both over- and underestimation of PEs in LAMIC compared to HIC. Nevertheless, the study confirms the basic finding that PEs are more frequent in LAMIC than in HIC.
Previous studies using resting-state functional neuroimaging have revealed alterations in whole-brain images, connectome-wide functional connectivity and graph-based metrics in groups of patients with schizophrenia relative to groups of healthy controls. However, it is unclear which of these measures best captures the neural correlates of this disorder at the level of the individual patient.
Here we investigated the relative diagnostic value of these measures. A total of 295 patients with schizophrenia and 452 healthy controls were investigated using resting-state functional Magnetic Resonance Imaging at five research centres. Connectome-wide functional networks were constructed by thresholding correlation matrices of 90 brain regions, and their topological properties were analyzed using graph theory-based methods. Single-subject classification was performed using three machine learning (ML) approaches associated with varying degrees of complexity and abstraction, namely logistic regression, support vector machine and deep learning technology.
Connectome-wide functional connectivity allowed single-subject classification of patients and controls with higher accuracy (average: 81%) than both whole-brain images (average: 53%) and graph-based metrics (average: 69%). Classification based on connectome-wide functional connectivity was driven by a distributed bilateral network including the thalamus and temporal regions.
These results were replicated across the three employed ML approaches. Connectome-wide functional connectivity permits differentiation of patients with schizophrenia from healthy controls at single-subject level with greater accuracy; this pattern of results is consistent with the ‘dysconnectivity hypothesis’ of schizophrenia, which states that the neural basis of the disorder is best understood in terms of system-level functional connectivity alterations.
The 22q11.2 deletion syndrome (22q11DS) is caused by a deletion on chromosome 22 locus q11.2. This copy number variant results in haplo-insufficiency of the catechol-O-methyltransferase (COMT) gene, and is associated with a significant increase in the risk for developing cognitive impairments and psychosis. The COMT gene encodes an enzyme that primarily modulates clearance of dopamine (DA) from the synaptic cleft, especially in the prefrontal cortical areas. Consequently, extracellular DA levels may be increased in prefrontal brain areas in 22q11DS, which may underlie the well-documented susceptibility for cognitive impairments and psychosis in affected individuals. This study aims to examine DA D2/3 receptor binding in frontal brain regions in adults with 22q11DS, as a proxy of frontal DA levels.
The study was performed in 14 non-psychotic, relatively high functioning adults with 22q11DS and 16 age- and gender-matched healthy controls (HCs), who underwent DA D2/3 receptor [18F]fallypride PET imaging. Frontal binding potential (BPND) was used as the main outcome measure.
BPND was significantly lower in adults with 22q11DS compared with HCs in the prefrontal cortex and the anterior cingulate gyrus. After Bonferroni correction significance remained for the anterior cingulate gyrus. There were no between-group differences in BPND in the orbitofrontal cortex and anterior cingulate cortex.
This study is the first to demonstrate lower frontal D2/3 receptor binding in adults with 22q11DS. It suggests that a 22q11.2 deletion affects frontal dopaminergic neurotransmission.
22q11.2 deletion syndrome (22q11DS), one of the most common recurrent copy number variant disorders, is associated with dopaminergic abnormalities and increased risk for psychotic disorders.
Given the elevated prevalence of substance use and dopaminergic abnormalities in non-deleted patients with psychosis, we investigated the prevalence of substance use in 22q11DS, compared with that in non-deleted patients with psychosis and matched healthy controls.
This cross-sectional study involved 434 patients with 22q11DS, 265 non-deleted patients with psychosis and 134 healthy controls. Psychiatric diagnosis, full-scale IQ and COMT Val158Met genotype were determined in the 22q11DS group. Substance use data were collected according to the Composite International Diagnostic Interview.
The prevalence of total substance use (36.9%) and substance use disorders (1.2%), and weekly amounts of alcohol and nicotine use, in patients with 22q11DS was significantly lower than in non-deleted patients with psychosis or controls. Compared with patients with 22q11DS, healthy controls were 20 times more likely to use substances in general (P < 0.001); results were also significant for alcohol and nicotine use separately. Within the 22q11DS group, there was no relationship between the prevalence of substance use and psychosis or COMT genotype. Male patients with 22q11DS were more likely to use substances than female patients with 22q11DS.
The results suggest that patients with 22q11DS are at decreased risk for substance use and substance use disorders despite the increased risk of psychotic disorders. Further research into neurobiological and environmental factors involved in substance use in 22q11DS is necessary to elucidate the mechanisms involved.
Depression has been associated with abnormalities in neural underpinnings of Reward Learning (RL). However, inconsistencies have emerged, possibly owing to medication effects. Additionally, it remains unclear how neural RL signals relate to real-life behaviour. The current study, therefore, examined neural RL signals in young, mildly to moderately depressed – but non-help-seeking and unmedicated – individuals and how these signals are associated with depressive symptoms and real-life motivated behaviour.
Individuals with symptoms along the depression continuum (n = 87) were recruited from the community. They performed an RL task during functional Magnetic Resonance Imaging and were assessed with the Experience Sampling Method (ESM), completing short questionnaires on emotions and behaviours up to 10 times/day for 15 days. Q-learning model-derived Reward Prediction Errors (RPEs) were examined in striatal areas, and subsequently associated with depressive symptoms and an ESM measure capturing (non-linearly) how anticipation of reward experience corresponds to actual reward experience later on.
Significant RPE signals were found in the striatum, insula, amygdala, hippocampus, frontal and occipital cortices. Region-of-interest analyses revealed a significant association between RPE signals and (a) self-reported depressive symptoms in the right nucleus accumbens (b = −0.017, p = 0.006) and putamen (b = −0.013, p = .012); and (b) the quadratic ESM variable in the left (b = 0.010, p = .010) and right (b = 0.026, p = 0.011) nucleus accumbens and right putamen (b = 0.047, p < 0.001).
Striatal RPE signals are disrupted along the depression continuum. Moreover, they are associated with reward-related behaviour in real-life, suggesting that real-life coupling of reward anticipation and engagement in rewarding activities might be a relevant target of psychological therapies for depression.
Abnormalities in reward learning in psychotic disorders have been proposed to be linked to dysregulated subcortical dopaminergic (DA) neurotransmission, which in turn is a suspected mechanism for predisposition to psychosis. We therefore explored the striatal dopaminergic modulation of reward processing and its behavioral correlates in individuals at familial risk for psychosis.
We performed a DA D2/3 receptor [18F]fallypride positron emission tomography scan during a probabilistic reinforcement learning task in 16 healthy first-degree relatives of patients with psychosis and 16 healthy volunteers, followed by a 6-day ecological momentary assessment study capturing reward-oriented behavior in the everyday life.
We detected significant reward-induced DA release in bilateral caudate, putamen and ventral striatum of both groups, with no group differences in its magnitude nor spatial extent. In both groups alike, greater extent of reward-induced DA release in all regions of interest was associated with better performance in the task, as well as in greater tendency to be engaged in reward-oriented behavior in the daily life.
These findings suggest intact striatal dopaminergic modulation of reinforcement learning and reward-oriented behavior in individuals with familial predisposition to psychosis. Furthermore, this study points towards a key link between striatal reward-related DA release and pursuit of ecologically relevant rewards.
There has been much debate as to whether the association between cannabis and subclinical expression of psychosis is causal, or whether psychotic experiences may prompt cannabis use in individuals at genetic risk for psychosis as a means of self-medication. The Genetic Risk and Outcome in Psychosis (GROUP) study investigated the association between familial liability for psychosis and sensitivity to cannabis, using patient sibling and sibling-control pairs analyses. This study focused on gene-environment interactions relevant to psychotic disorders, and included patients with psychotic disorder, their siblings and community controls. Caspi and colleagues highlighted the importance of individual genetic vulnerability when they reported an interaction between cannabis use and variation in the gene that encodes catecholamine-O-methyl transferase (COMT). Given that different types of cannabis clearly affect mental health differentially, more research is needed to understand how genetic liability may increase sensitivity to, or preference for, the specific constituents of cannabis.
Lack of social interaction, which is characteristically seen in people
with autistic-spectrum disorder, may be caused by malfunctioning of the
frontostriatal reward systems. However, no reported in
vivo brain imaging studies have investigated reward
mechanisms in autistic-spectrum disorder.
To investigate functional brain activation during reward feedback in
people with autistic-spectrum disorder and control individuals.
We used event-related functional magnetic resonance imaging to examine
the neural substrates of monetary reward in individuals with
autistic-spectrum disorder and matched controls.
When rewarded, individuals with autism compared with control individuals
showed significantly greater brain activation in the left anterior
cingulate gyrus. In addition, activation of this region was negatively
correlated with social interaction as measured by the Autism Diagnostic
In people with autistic-spectrum disorder, achieving reward is associated
with significant differences in the activation of areas known to be
responsible for attention and arousal, and this may partially underpin
some deficits in social behaviour.
We studied the functional neuroanatomy of social behaviour in
velo-cardio-facial syndrome (VCFS) using a facial emotional processing task
and functional magnetic resonance imaging in adults with this syndrome and
controls matched for age and IQ. The VCFS group had less activation in the
right insula and frontal brain regions and more activation in occipital
regions. Genetically determined abnormalities in pathways including those
involved in emotional processing may underlie deficits in social cognition
in people with VCFS.
Stephan Eliez, Division of Child and Adolescent Psychiatry, Geneva University School of Medicine, Switzerland,
Therese van Amelsvoort, Department of Psychiatry, Academic Medical Centre, Amsterdam, Holland
Kieran C. Murphy, Education and Research Centre, Royal College of Surgeons of Ireland,Peter J. Scambler, Institute of Child Health, University College London
This chapter discusses the currently available neuroimaging literature in people with velo-cardio-facial syndrome (VCFS), and explains how this contributes to our understanding of the neurobiology of schizophrenia in the general population. Several publications have investigated quantitative volumetric changes in VCFS children and adolescents. Structural alteration of the cerebellum in children and adolescents with VCFS was congruent with several qualitative studies reporting reduction in posterior fossa, cerebellum, or vermis. Using cross-sectional data analysis, changes of temporal and mesio-temporal lobe structures in individuals with VCFS compared with typically developing subjects were investigated. Imprinting is a genetic mechanism in which gene expression is modulated by the parental origin of the chromosome on which the gene is located. Research on imprinting has shown that parental origin of a genomic deletion can affect the physical and cognitive phenotype of individuals with the genetic disorder.
Velo-cardio-facial syndrome (VCFS) is associated with deletions in the q11 band of chromosome 22, learning disability and psychosis, but the neurobiological basis is poorly understood.
To investigate brain anatomy in adults with VCFS.
Magnetic resonance imaging was used to study 10 patients with VCFS and 13 matched controls. We carried out three analyses: qualitative; traced regional brain volume; and measurement of grey and white matter volume.
The subjects with VCFS had: a high prevalence of white matter hyperintensities and abnormalities of the septum pellucidum; a significantly smaller volume of cerebellum; and widespread differences in white matter bilaterally and regional specific differences in grey matter in the left cerebellum, insula, and frontal and right temporal lobes.
Deletion at chromosome 22q11 is associated with brain abnormalities that are most likely neurodevelopmental and may partially explain the high prevalence of learning disability and psychiatric disorder in VCFS.