Anne-Kathrin Fett

City, University of London · Department of Psychology

Positive and negative schizotypy reflect distinct patterns of subclinical traits in the general population associated with neurodevelopmental and schizophrenia-spectrum pathologies. Yet, a comprehensive characterization of the unique and shared neuroanatomical signatures of these schizotypy dimensions is lacking. Leveraging 3D brain MRI data from 2...

Introduction Regional gray matter (GM) alterations have been reported in early-onset psychosis (EOP, onset before age 18), but previous studies have yielded conflicting results, likely due to small sample sizes and the different brain regions examined. In this study, we conducted a whole brain voxel-based morphometry (VBM) analysis in a large sampl...

In many individuals with a diagnosis of schizophrenia social functioning is impaired across the lifespan. Social cognition has emerged as one of the possible factors that may contribute to these challenges. Neuroimaging research can give further insights into the underlying mechanisms of social (cognitive) difficulties. This review summarises the e...

Ecological momentary assessment (EMA), a structured diary assessment technique, has shown feasibility to capture psychotic(-like) symptoms across different study groups. We investigated whether EMA combined with unsupervised machine learning can distinguish groups on the continuum of genetic risk toward psychotic illness and identify individuals wi...

Background: Schizophrenia (SZ) and autism spectrum disorders (ASD) are characterized by difficulties in theory of mind (ToM). We examined group differences in performance on a ToM-related test and associations with an estimated IQ. Methods: Participants [N = 1227, SZ (n = 563), ASD (n = 159), and controls (n = 505), 32.2% female] completed the R...

Glutamatergic dysfunction is associated with failure to respond to antipsychotic medication in individuals with schizophrenia. Our objective was to combine neurochemical and functional brain imaging methods to investigate glutamatergic dysfunction and reward processing in such individuals compared with those with treatment responsive schizophrenia,...

Background Social cognitive impairment is a recognized feature of psychotic disorders. However, potential age-related differences in social cognitive impairment have rarely been studied. Study Design Data came from 905 individuals with a psychotic disorder, 966 unaffected siblings, and 544 never-psychotic controls aged 18–55 who participated in th...

Background: The role of loneliness and social exclusion in the development of paranoia is largely unexplored. Negative affect may mediate potential associations between these factors. We investigated the temporal relationships of daily-life loneliness, felt social exclusion, negative affect, and paranoia across the psychosis continuum. Method: S...

Aims: Schizotypy reflects the vulnerability to schizophrenia in the general population. Different questionnaires have been developed to measure aspects of schizotypy. Higher schizotypy scores have also been linked with depression, anxiety, and stress sensitivity. Here we examine the associations of schizotypy with symptoms of depression and anxiet...

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 sub...

Background Conventional pharmacological approaches have limited effectiveness for schizophrenia. There is interest in the application of oxytocin, which is involved in social cognition. Clinical trials have yielded mixed results, with a gap in understanding neural mechanisms. Aims To evaluate the behavioural impact of oxytocin administration on a...

Given the links between the built environment and loneliness, there is interest in using place-based approaches (addressing built environment characteristics and related socio-spatial factors) in local communities to tackle loneliness and mental health problems. However, few studies have described the effectiveness, acceptability, or potential harm...

Social isolation has been suggested to foster paranoia. Here we investigate whether social company (i.e., being alone vs. not) and its nature (i.e., stranger/distant vs. familiar other) affects paranoia differently depending on psychosis risk. Social interactions and paranoid thinking in daily life were investigated in 29 patients with clinically s...

Neuroanatomical abnormalities have been reported along a continuum from at-risk stages, including high schizotypy, to early and chronic psychosis. However, a comprehensive neuroanatomical mapping of schizotypy remains to be established. The authors conducted the first large-scale meta-analyses of cortical and subcortical morphometric patterns of sc...

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 Mu...

Cognitive impairment is a well-recognized key feature of schizophrenia. Here we review the evidence on (1) the onset and sensitive periods of change in cognitive impairment before and after the first psychotic episode, and (2) heterogeneity in neurocognitive presentations across cognitive domains between and within individuals. Overall, studies sug...

Objectives: Social contact is known to be beneficial for humans’ mental health. Individuals with psychotic symptoms (PS) tend to show poorer social and interpersonal functioning. However, in this patient population, social contact may be crucial for their mental wellbeing and treatment success. Additionally, closeness of social contact (familiar ve...

Trust is essential for establishing and maintaining cooperative behaviors between individuals and institutions in a wide variety of social, economic, and political contexts. This book explores trust through the lens of neurobiology, focusing on empirical, methodological, and theoretical aspects. Written by a distinguished group of researchers from...

Objective: Recent findings suggest that diminished processing of positive contextual information about others during interactions may contribute to social impairment in the schizophrenia spectrum. This could be due to general social context processing deficits or specific biases against positive information. We studied the impact of positive and n...

Objectives: Theory of Mind (ToM) plays a role in social functioning and is impaired in patients with schizophrenia and to a lesser degree in first-degree relatives relative to healthy controls. This study investigates whether attachment styles moderate these observed group differences in ToM. Methods: This cross-sectional study included a sample...

Neuroanatomical abnormalities have been reported along a continuum from at-risk stages, including high schizotypy, to early and chronic psychosis. However, a comprehensive neuroanatomical mapping of schizotypy remains to be established. The authors conducted the first large-scale meta-analyses of cortical and subcortical morphometric patterns of sc...

Epidemiological studies suggest that the observed association between urbanicity and psychosis may be explained in part by social deprivation, reduced social capital affecting cohesion and trust, and minority group and ethnic density effects, which in turn may represent aspects of “social defeat.” In addition, urbanicity is also associated with pol...

Early‐onset psychosis disorders are serious mental disorders arising before the age of 18 years. Here, we investigate the largest neuroimaging dataset, to date, of patients with early‐onset psychosis and healthy controls for differences in intracranial and subcortical brain volumes. The sample included 263 patients with early‐onset psychosis (mean...

Background Cortical neuroanatomical abnormalities have been reported along a continuum between individuals with chronic schizophrenia, first-episode psychosis, clinical high risk for psychosis, and healthy individuals self-reporting subclinical psychotic-like experiences (or schizotypy). Recently, the Schizophrenia Working Group within the ENIGMA (...

Background Negative symptoms can be seen to represent a continuum from subclinical manifestations in the general population to severe symptoms in schizophrenia. Neuroanatomical studies show evidence of fronto-striatal structural abnormalities linked to negative symptoms in patients with schizophrenia (Walton et al. 2018). However, it remains an ope...

Twenty-first century urbanization poses increasing challenges for mental health. Epidemiological studies have shown that mental health problems often accumulate in urban areas, compared to rural areas, and suggested possible underlying causes associated with the social and physical urban environments. Emerging work indicates complex urban effects t...

Background: Limited evidence has indicated that addition of a steroidal mineralocorticoid receptor antagonist (MRA) to the standard of care reduces proteinuria in patients with diabetic kidney disease (DKD); however, there are limited data regarding real-world MRA use in these patients. This study aimed to describe the characteristics of spironola...

Importance: It remains uncertain whether people with psychotic disorders experience progressive cognitive decline or normal cognitive aging after first hospitalization. This information is essential for prognostication in clinical settings, deployment of cognitive remediation, and public health policy. Objective: To examine long-term cognitive c...

This study examined the feasibility and effectiveness of an interactive smartphone application that aimed to improve daily-life social functioning and symptoms in schizophrenia spectrum disorders (SZ) with Experience Sampling Method (ESM) derived personalised feedback.Two groups of outpatients with a diagnosis of SZ were included (one receiving ESM...

Patients with a disorder in the schizophrenia spectrum (SZ) demonstrate impairments in reward learning. A reduced sensitivity to social reward may impede social beyond non-social reward learning mechanisms. The aim of the current study was to investigate social and non-social reward learning in SZ by means of two interactive game-theoretical invest...

In chronic psychosis, reduced trust is associated with a neural insensitivity to social reward and reduced theory of mind (ToM). Here we investigate whether these mechanisms could underlie emerging social impairments in early psychosis. Twenty-two participants with early psychosis and 25 controls (male, 13-19 years) participated in two interactive...

Objective Elevated prevalence of non-affective psychotic disorders is often found in densely populated areas. This functional magnetic resonance imaging study investigates if reduced trust, a component of impaired social functioning in patients with psychotic disorder, is associated with urban upbringing. Methods In total, 39 patients (22 first ep...

The current meta-analysis explored relationships between functional outcomes in schizophrenia spectrum disorders and different domains of neurocognition and social cognition. Literature searches were conducted in PsycINFO, PubMed, and ProQuest to identify articles reporting correlations between cognition domains and functional outcomes. Of 1,361 ar...

Background Trust and reciprocity toward others have often been found to increase from childhood to adulthood. Gender differences in these social behaviors have been reported in adults. While adolescence is a key-period of change in social behavior, gender differences in trust and reciprocity during this developmental stage have rarely been investig...

Abstract Background Steroidal mineralocorticoid receptor antagonists (MRAs) are recommended for the treatment of heart failure (HF) and resistant hypertension, both common comorbidities in patients with diabetes and chronic kidney disease (CKD). This study explored the clinical characteristics of, and steroidal MRA use in, patients with CKD with an...

Background Neuroanatomical studies have provided some evidence for a neurobiological continuity between psychotic symptoms in patients with schizophrenia and subclinical psychotic-like experiences as identified via self-report questionnaires (or schizotypy) in otherwise healthy individuals. Despite a number of structural brain imaging studies publi...

Background In chronic psychosis, the loss of trust towards others is associated with a neural insensitivity to social reward and reduced theory of mind (ToM). The aim of this study was to investigate whether these mechanisms are already present in early psychosis. Methods Twenty-two participants with early psychosis and 25 controls (male, 13–19 ye...

Background Elevated incidence rates of non-affective psychosis and psychotic symptoms in densely populated urban areas have been reported by many epidemiological studies. It has been proposed that social characteristics of the urban environment underlie the association with the development of psychotic disorders. Individuals at risk for psychosis m...

Purpose of review: Epidemiological studies associate city living with an elevated psychosis risk. Urban (social/economic) stress and exposure to environmental toxins, pollution or disease agents have been proposed to underlie this association. This review provides an update on the recent evidence (May 2017 - November 2018). Recent findings: Of 6...

Background: Psychosis is characterized by problems in social functioning and trust, the assumed glue to positive social relations. But what helps building trust? A prime candidate could be social mindfulness: the ability and willingness to see and consider another person’s needs and wishes during social decision making. We investigated whether firs...

Importance Many studies have investigated impairments in cognitive domains in adults with autism spectrum disorder (ASD). Yet, to date, a comprehensive overview on the patterns of cognitive functioning is lacking. Objective To provide an overview of nonsocial and social cognitive functioning in various domains in adults with ASD, allowing for comp...

Background Trauma due to deliberate harm by others is known to increase the likelihood of developing Post-Traumatic Stress Disorder (PTSD). This is the first study investigating basic and dynamic trust in ‘interpersonal’ PTSD. Methods Thirty-two participants with PTSD and 22 healthy controls played a novel multi-round version of a monetary investm...

Patients with schizophrenia show reduced cooperation and less sensitivity to social cues in pairwise interactions, however, it remains unclear whether these mechanisms are also present in interactions within social groups. We used a public goods game to investigate cooperation and sensitivity to social feedback in group interactions in 27 patients...

Background Psychosis is characterized by problems in social functioning that exist well before illness onset, and in individuals at clinical high risk (CHR) for psychosis. Trust is an essential element for social interactions that is impaired in psychosis. In the trust game, chronic patients showed reduced baseline trust, impaired response to posit...

Introduction: The prevalence of type 2 diabetes mellitus (T2DM) is increasing in the U.S. and 40% of affected people develop chronic kidney disease (CKD). This study evaluated patients’ treatment patterns, disease burden and progression. Methods: This retrospective study used the U.S. claims database PharMetrics Plus (January 2006-December 2015) an...

Background Knowledge about the long-term cognitive course in psychotic disorders is limited. In this 18-year follow-up of participants of the Suffolk County project we report on the longitudinal course of cognitive performance in individuals with schizophrenia spectrum disorders, affective psychoses and other psychoses. We investigate (i) change in...

Objective: Kraepelin considered declining course a hallmark of schizophrenia, but others have suggested that outcomes usually stabilize or improve after treatment initiation. The authors investigated this question in an epidemiologically defined cohort with psychotic disorders followed for 20 years after first hospitalization. Method: The Suffol...

Background: Positive symptoms and specifically paranoid delusions in psychosis are characterized by a fundamental luck of trust. A number of studies show that dopaminergic dysfunction modulating the cortico-striatal reward network underlies psychosis. However, antipsychotic medication is not effective in approximately a third of schizophrenia patie...

Background: Schizophrenia is associated with deficits in (social) cognition and reward learning. Aberrant reward learning processes may underlie reduced motivation in social and nonsocial contexts. However, recent evidence suggests that an insensitivity to social cues in schizophrenia might additionally impair social reward learning beyond nonsocia...

Background: Schizophrenia (SZ) is related to impairments in social functioning. Previous studies investigating pairwise interactions indicate that reduced cooperation and a reduced sensitivity to social cues might cause these fundamental social deficits. However, research on cooperation and sensitivity to social information in group interactions is...

Background: Growing up in an urban environment is associated with a higher incidence of schizophrenia. The effects of urbanicity seem particularly pronounced during development. It has been hypothesized that urbanicity could be a proxy for social stress, which might account for disturbed social interactions and trust in the disorder. Yet, how urban...

Trust and cooperation increase from adolescence to adulthood, but studies on gender differences in this development are rare. We investigated gender and age-related differences in trust and reciprocity and associated neural mechanisms in 43 individuals (16 to 27 years, 22 male). Participants played two multi-round trust games with a cooperative and...

Objective: Social impairment is a long-recognized core feature of schizophrenia and is common in other psychotic disorders. Still, to date the long-term trajectories of social impairment in psychotic disorders have rarely been studied systematically. Methods: Data came from the Suffolk County Mental Health Project, a 20-year prospective study of...

Objective: Social impairment is a long-recognized core feature of schizophrenia and is common in other psychotic disorders. Still, to date the long-term trajectories of social impairment in psychotic disorders have rarely been studied systematically. Methods: Data came from the Suffolk County Mental Health Project, a 20-year prospective study of...

Distrust and social dysfunction are characteristic in psychosis and may arise from attachment insecurity, which is elevated in the disorder. The relationship between trust and attachment in the early stages of psychosis is unknown, yet could help to understand interpersonal difficulties and disease progression. This study aimed to investigate wheth...

Introduction: Paranoid delusions have been associated with a tendency to over-attribute intentionality and contingency to others' actions and incidental events in individuals with chronic psychosis. However, this hyper-associative perception bias has not been investigated in the early illness stages of psychosis, during which it may play a particu...

Background: There is an increasing interest in cognitive-behavioural therapy (CBT) interventions targeting negative symptoms in schizophrenia. To date, CBT trials primarily focused on positive symptoms and investigated change in negative symptoms only as a secondary outcome. To enhance insight into factors contributing to improvement of negative s...

Social neuroscience is a flourishing, interdisciplinary field that investigates the underlying biological processes of social cognition and behaviour. The recent application of social neuroscience to psychiatric research advances our understanding of various psychiatric illnesses that are characterized by impairments in social cognition and social...

Background: Psychosis is characterized by a profound lack of trust and disturbed social interactions. Investigating the neural basis of these deficits is difficult because of medication effects but first-degree relatives show qualitatively similar abnormalities to patients with psychosis on various tasks. This study aimed to investigate neural act...

Psychotische stoornissen hebben vaak een prominent sociaal karakter. Dit komt tot uiting in sociaal-cognitieve afwijkingen, sociale terugtrekking en sociale isolatie. Problemen met sociale cognitie worden in verband gebracht met het ontstaan en de instandhouding van psychotische symptomen. Daarnaast blijken sociaal-cognitieve vaardigheden van patië...

Changes in social behaviour from childhood to adulthood have been suggested to be driven by an increased sensitivity to others' perspectives. Yet, the link between perspective-taking and social processes, such as trust and reciprocity, has rarely been investigated during adolescence. Using two trust games with a cooperative and an unfair counterpar...

Psychosis is characterized by an elementary lack of trust in others. Trust is an inherently rewarding aspect of successful social interactions and can be examined using neuroeconomic paradigms. This study was aimed at investigating the underlying neural basis of diminished trust in psychosis. Functional magnetic resonance imaging data were acquired...

Objective: Impaired Theory of Mind (ToM) is found in adults with schizophrenia and is associated with paranoid symptoms. Insecure attachment is proposed to underlie impaired ToM as well as paranoia. Insight into associations between insecure attachment and impaired ToM skills may help clinicians and patients to understand interpersonal difficultie...

The tendency to trust and to cooperate increases from adolescence to adulthood. This social development has been associated with improved mentalising and age-related changes in brain function. Thus far, there is limited imaging data investigating these associations. We used two trust games with a trustworthy and an unfair partner to explore the bra...

Background: Schizophrenia is associated with poor quality of life (QOL). Whereas the effects of neurocognitive deficits and psychopathology on QOL of schizophrenia patients have recently been elucidated, little is known about the influence of social cognitive deficits. This study investigated the influence of social cognitive deficits on QOL in sch...

Schizophrenia is associated with poor quality of life (QOL). Whereas the effects of neurocognitive deficits and psychopathology on QOL of schizophrenia patients have recently been elucidated, little is known about social cognitive deficits in this regard. This study investigated the influence of social cognition on QOL in schizophrenia. A sample of...

Psychotic illness is a disorder of social interaction unique to humans. However, up to now research has failed to pin down the exact determinants of the complex and interactive processes associated with the development of trust and reciprocity in psychosis. Utilizing a novel multi-round version of an interactive trust game experiment, we show that...

Social cognitive deficits are associated with psychotic symptoms, but the nature of this association remains unknown. This study uses a genetically sensitive cross-trait cross-sibling design to investigate the nature of the overlap between both phenotypes. A sample of 1032 patients, 1017 of their healthy siblings, and 579 control subjects were recr...

Relatively few studies have examined how patients with schizophrenia and depression view psychiatric research and what influences their readiness to participate. A total of 763 patients (48% schizophrenia, 52% depression) from 7 European countries were examined using a specifically designed self-report questionnaire ["Hamburg Attitudes to Psychiatr...

The current systematic review and meta-analysis provides an extended and comprehensive overview of the associations between neurocognitive and social cognitive functioning and different types of functional outcome. Literature searches were conducted in MEDLINE and PsycINFO and reference lists from identified articles to retrieve relevant studies on...

Effects of cue exposure to high and low-caloric food on body image satisfaction and the moderating role of body mass index (BMI) and restraint were investigated in 77 lean unrestrained, lean restrained and overweight restrained females. Body (BS) and weight satisfaction (WS) were assessed before and after the cue exposure. Lean restrained participa...

The influence of dietary restraint and food exposure on body satisfaction was tested. Body and weight satisfaction were measured before and after exposure to either high- or low-caloric food, without actual eating. Independent of caloric condition, higher dietary restraint was associated with a decrease in body satisfaction after food exposure. Wit...

The effects of cue exposure to high- and low-calorie food on body and weight satisfaction (BS, WS) were investigated in 73 females. Based on previous food cue exposure and intake studies, it was hypothesised that BS and WS would decrease following exposure to high in comparison to low-calorie food. Furthermore, moderating effects of body mass index...

The influence of exposure to high- and low-caloric food cues on body and weight dissatisfaction was tested in 30 high- and 31 low-restrained (LR) eaters. Body and weight satisfaction were measured before and after exposure to either high- or low-caloric food cues (between-subject design). Contrary to our prediction, there was no differential effect...

High-calorie intake is associated with changes in state body satisfaction, and is moderated by dietary restraint and body mass index. This implies that food intake signals fear of overeating and weight increase in specific populations. Four experiments addressed aspects of this putative relationship by direct manipulation of energy intake and expos...

Research on the effect of acute stress and high levels of glucocorticoids on memory has largely focused on memory tasks involving the medial temporal lobe (e.g., declarative memory). Less is known, however, about the effects of stress and glucocorticoids on more strategic memory processes regulated by the prefrontal cortex (e.g., source monitoring)...