Psychosis and urbanicity – a review of the recent literature from epidemiology to neurourbanism

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 645-screened studies, 17 on: (1) urbanicity-psychosis associations in worldwide high, middle and low-income countries, (2) explanatory mechanisms, including nature exposure, social and economic stressors and genetic risk; (3) urbanicity effects on the brain and coping; and (4) urbanicity and resources, were included. The reviewed evidence revealed complex patterns of urbanicity-psychosis associations with considerable international variation within Europe and between low, middle and high-income countries worldwide. Social and economic stressors (e.g. migration, ethnic density, economic deprivation), nature exposure and access to resources could only explain part of the urbanicity effects. Risk factors differed between countries and between affective and non-affective psychosis. Summary: Urbanicity-psychosis associations are heterogeneous and driven by multiple risk and protective factors that seem to act differently in different ethnic groups and countries. Interdisciplinary research combining approaches, e.g. from experimental neuroscience and epidemiology, is needed to unravel specific urban mechanisms that in- or decrease psychosis risk

Remotely acting SMCHD1 gene regulatory elements: in silico prediction and identification of potential regulatory variants in patients with FSHD

Background: Facioscapulohumeral dystrophy (FSHD) is commonly associated with contraction of the D4Z4 macro-satellite repeat on chromosome 4q35 (FSHD1) or mutations in the SMCHD1 gene (FSHD2). Recent studies have shown that the clinical manifestation of FSHD1 can be modified by mutations in the SMCHD1 gene within a given family. The absence of either D4Z4 contraction or SMCHD1 mutations in a small cohort of patients suggests that the disease could also be due to disruption of gene regulation. In this study, we postulated that mutations responsible for exerting a modifier effect on FSHD might reside within remotely acting regulatory elements that have the potential to interact at a distance with their cognate gene promoter via chromatin looping. To explore this postulate, genome-wide Hi-C data were used to identify genomic fragments displaying the strongest interaction with the SMCHD1 gene. These fragments were then narrowed down to shorter regions using ENCODE and FANTOM data on transcription factor binding sites and epigenetic marks characteristic of promoters, enhancers and silencers

Girls-Boys: An Investigation of Gender Differences in the Behavioral and Neural Mechanisms of Trust and Reciprocity in Adolescence

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 investigated. Methods: Here we investigate age-related gender differences in trust and reciprocity (n = 100, 51 female) and associated neural mechanisms (n = 44, 20 female) in adolescents between 13 and 19 years of age. Participants played two multi-round trust games with a pre-programmed cooperative and an unfair partner. Forty-four of 100 participants completed the trust game while undergoing functional brain imaging. Results: Participants’ investments were greater toward a cooperative than unfair game partner (p < 0.01), showing sensitivity to the degree of trustworthiness. There were no gender or age or related differences in baseline trust. In repeated cooperative interactions no gender differences were found, but younger adolescents showed slightly steeper increase of investments than older adolescents. In unfair interactions, younger males reacted with stronger decrease of investments than older males. Region of interest analysis of brain areas associated with in mentalizing, reward learning, conflict processing, and cognitive control revealed gender-by-age interactions on trusting behavior in the temporo-parietal junction (TPJ) and the caudate, showing stronger influence of age in males than in females during cooperation, and the reverse in unfair interactions. Additionally, main effects of gender were found in the TPJ, with higher activation in males, and in the caudate, with females showing greater activation. Conclusion: In first interactions and during repeated cooperative interactions, adolescent males and females showed similar trusting behavior. Younger males showed stronger responses to unfairness by others. Gender-by-age interactions in specific ROIs suggest differential development in mentalizing and reward related cognitive processes. In conjunction with previous research, our findings suggest the presence of subtle gender and age-related changes in trust and cooperation that are only detectable using larger age windows

Trust and the city: Linking urban upbringing to neural mechanisms of trust in psychosis

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 episode and 17 clinical high risk) and 30 healthy controls, aged 16–29, performed two multi-round trust games, with a cooperative and unfair partner during functional magnetic resonance imaging scan-ning. Baseline trust was operationalized as the first investment made, and changes of trust as changes in investments made over the 20 trials during the games. Urban exposure during upbringing (0–15 years) was defined as higher urban (≥2500 inhabitants/km2) or lower urban (<2500 inhabitants/km2). Results: Patients displayed lower baseline trust (first investment) than controls, regardless of urbanicity exposure. During cooperative interactions, lower-urban patients showed increasing investments. In addition, during cooperative interactions, group-by-developmental urbanicity interactions were found in the right and left amygdalae, although for the latter only at trend level. Higher urbanicity was associated with decreased activation of the left amygdala in patients and controls during investments and with increased activation of the right and left amygdalae in patients only, during repayments. During unfair interactions, no associations of urbanicity with behavior or brain activation were found. Conclusion: Urban upbringing was unrelated to baseline trust. Associations with urbanicity were stronger for patients compared to controls, suggesting greater susceptibility to urbanicity effects during the developmental period. Higher-urban patients failed to compensate for the initial distrust specifically during repeated cooperative interactions. This finding highlights potential implications for social functioning. Urban upbringing was linked to dif-ferential amygdala activation, suggesting altered mechanisms of feedback learning, but this was not associated with trust game behavio

Non-persistente virusoverdracht door bladluizen in bloembollen

Dit driejarig onderzoeksproject naar non-persistente virusoverdracht door bladluizen in bloembollen heeft direct toepasbare kennis en gewasbeschermingsadviezen opgeleverd, maar ook heldere adviezen voor zowel de chemische als biologische bestrijding van virusoverdracht door bladluizen. Deze adviezen vormen de basis voor verder onderzoek om uiteindelijk de non-persistente virusverspreiding door bladluizen nog effectiever te kunnen bestrijden

Understanding the mechanisms underlying cognitive control in psychosis

Background Cognitive control (CC) involves a top–down mechanism to flexibly respond to complex stimuli and is impaired in schizophrenia. Methods This study investigated the impact of increasing complexity of CC processing in 140 subjects with psychosis and 39 healthy adults, with assessments of behavioral performance, neural regions of interest and symptom severity. Results The lowest level of CC (Stroop task) was impaired in all patients; the intermediate level of CC (Faces task) with explicit emotional information was most impaired in patients with first episode psychosis. Patients showed activation of distinct neural CC and reward networks, but iterative learning based on the higher-order of CC during the trust game, was most impaired in chronic schizophrenia. Subjects with first episode psychosis, and patients with lower symptom load, demonstrate flexibility of the CC network to facilitate learning, which appeared compromised in the more chronic stages of schizophrenia. Conclusion These data suggest optimal windows for opportunities to introduce therapeutic interventions to improve CC

Girls-boys: an investigation of gender differences in the behavioral and neural mechanisms of trust and reciprocity in adolescence

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 investigated. Methods: Here we investigate age-related gender differences in trust and reciprocity (n = 100, 51 female) and associated neural mechanisms (n = 44, 20 female) in adolescents between 13 and 19 years of age. Participants played two multi-round trust games with a pre-programmed cooperative and an unfair partner. Forty-four of 100 participants completed the trust game while undergoing functional brain imaging. Results: Participants’ investments were greater toward a cooperative than unfair game partner (p < 0.01), showing sensitivity to the degree of trustworthiness. There were no gender or age or related differences in baseline trust. In repeated cooperative interactions no gender differences were found, but younger adolescents showed slightly steeper increase of investments than older adolescents. In unfair interactions, younger males reacted with stronger decrease of investments than older males. Region of interest analysis of brain areas associated with in mentalizing, reward learning, conflict processing, and cognitive control revealed gender-by-age interactions on trusting behavior in the temporo-parietal junction (TPJ) and the caudate, showing stronger influence of age in males than in females during cooperation, and the reverse in unfair interactions. Additionally, main effects of gender were found in the TPJ, with higher activation in males, and in the caudate, with females showing greater activation. Conclusion: In first interactions and during repeated cooperative interactions, adolescent males and females showed similar trusting behavior. Younger males showed stronger responses to unfairness by others. Gender-by-age interactions in specific ROIs suggest differential development in mentalizing and reward related cognitive processes. In conjunction with previous research, our findings suggest the presence of subtle gender and age-related changes in trust and cooperation that are only detectable using larger age windows