Global population attributable fraction of potentially modifiable risk factors for mental disorders: a meta-umbrella systematic review

Exploring causal mechanisms of psychosis risk

Robust epidemiological evidence of risk and protective factors for psychosis is essential to inform preventive interventions. Previous evidence syntheses have classified these risk and protective factors according to their strength of association with psychosis. In this critical review we appraise the distinct and overlapping mechanisms of 25 key environmental risk factors for psychosis, and link these to mechanistic pathways that may contribute to neurochemical alterations hypothesised to underlie psychotic symptoms. We then discuss the implications of our findings for future research, specifically considering interactions between factors, exploring universal and subgroup-specific factors, improving understanding of temporality and risk dynamics, standardising operationalisation and measurement of risk and protective factors, and developing preventive interventions targeting risk and protective factors.

The lived experience of mental disorders in adolescents: a bottom-up review co-designed, co-conducted and co-written by experts by experience and academics

We provide here the first bottom-up review of the lived experience of mental disorders in adolescents co-designed, co-conducted and co-written by experts by experience and academics. We screened first-person accounts within and outside the medical field, and discussed them in collaborative workshops involving numerous experts by experience - representing different genders, ethnic and cultural backgrounds, and continents - and their family members and carers. Subsequently, the material was enriched by phenomenologically informed perspectives and shared with all collaborators. The inner subjective experience of adolescents is described for mood disorders, psychotic disorders, attention-deficit/hyperactivity disorder, autism spectrum disorders, anxiety disorders, eating disorders, externalizing disorders, and self-harm behaviors. The recollection of individuals' past histories also indexes the prodromal (often transdiagnostic) features predating the psychiatric diagnosis. The experience of adolescents with mental disorders in the wider society is described with respect to their family, their school and peers, and the social and cultural context. Furthermore, their lived experience of mental health care is described with respect to receiving a diagnosis of mental disorder, accessing mental health support, receiving psychopharmacological treatment, receiving psychotherapy, experiencing peer support and mental health activism, and achieving recovery. These findings can impact clinical practice, research, and the whole society. We hope that this co-designed, co-conducted and co-written journey can help us maintain our commitment to protecting adolescents' fragile mental health, and can help them develop into a healthy, fulfilling and contributing adult life.

Population attributable fractions of modifiable risk factors for dementia: a systematic review and meta-analysis

BACKGROUND

More than 57 million people have dementia worldwide. Evidence indicates a change in dementia prevalence and incidence in high-income countries, which is likely to be due to improved life-course population health. Identifying key modifiable risk factors for dementia is essential for informing risk reduction and prevention strategies. We therefore aimed to estimate the population attributable fraction (PAF) for dementia associated with modifiable risk factors.

METHODS

In this systematic review and meta-analysis, we searched Embase, MEDLINE, and PsycINFO, via Ovid, from database inception up to June 29, 2023, for population-derived or community-based studies and reviews reporting a PAF value for one or more modifiable risk factor for later-life dementia (prevalent or incident dementia in people aged ≥60 years), with no restrictions on dementia subtype, the sex or baseline age of participants, or the period of study. Articles were independently screened for inclusion by four authors, with disagreements resolved through consensus. Data including unweighted and weighted PAF values (weighted to account for communality or overlap in risk) were independently extracted into a predefined template by two authors and checked by two other authors. When five or more unique studies investigated a given risk factor or combination of the same factors, random-effects meta-analyses were used to calculate a pooled PAF percentage estimate for the factor or combination of factors. The review protocol was registered on PROSPERO, CRD42022323429.

FINDINGS

4024 articles were identified, and 74 were included in our narrative synthesis. Overall, PAFs were reported for 61 modifiable risk factors, with sufficient data available for meta-analysis of 12 factors (n=48 studies). In meta-analyses, the highest pooled unweighted PAF values were estimated for low education (17·2% [95% CI 14·4-20·0], p<0·0001), hypertension (15·8% [14·7-17·1], p<0·0001), hearing loss (15·6% [10·3-20·9], p<0·0001), physical inactivity (15·2% [12·8-17·7], p<0·0001), and obesity (9·4% [7·3-11·7], p<0·0001). According to weighted PAF values, low education (9·3% [6·9-11·7], p<0·0001), physical inactivity (7·3% [3·9-11·2], p=0·0021), hearing loss (7·2% [5·2-9·7], p<0·0001), hypertension (7·1% [5·4-8·8], p<0·0001), and obesity (5·3% [3·2-7·4], p=0·0001) had the highest pooled estimates. When low education, midlife hypertension, midlife obesity, smoking, physical inactivity, depression, and diabetes were combined (Barnes and Yaffe seven-factor model; n=9 studies), the pooled unweighted and weighted PAF values were 55·0% (46·5-63·5; p<0·0001) and 32·0% (26·6-37·5; p<0·0001), respectively. The pooled PAF values for most individual risk factors were higher in low-income and middle-income countries (LMICs) versus high-income countries.

INTERPRETATION

Governments need to invest in a life-course approach to dementia prevention, including policies that enable quality education, health-promoting environments, and improved health. This investment is particularly important in LMICs, where the potential for prevention is high, but resources, infrastructure, budgets, and research focused on ageing and dementia are limited.

FUNDING

UK Research and Innovation (Medical Research Council).

Risk and Protective Factors of Self-harm and Suicidality in Adolescents: An Umbrella Review with Meta-Analysis

Suicide remains the second most common cause of death in young people aged 10-24 years and is a growing concern globally. The literature reports a vast number of factors that can predispose an adolescent to suicidality at an individual, relational, community, or societal level. There is limited high-level research identifying and understanding these risk and protective factors of adolescent suicidality. The present study used an umbrella review and meta-analysis to synthesize evidence from the review literature in the past 20 years on risk and protective factors of self-harm and suicidality (behavior and ideation) in adolescents. The umbrella review included 33 quantitative reviews with 1149 individual studies on suicidality and self-harm. Based on the data synthesis, it compared the public health impact of exposure on the population of the identified exposure. Bullying victimization was the most attributed environmental exposure for suicidality. The other identified significant school and individual factors were sleeping disturbance, school absenteeism, and exposure to antidepressants. Several significant vulnerable young populations were identified with significantly higher prevalence of suicidality, including lesbian, gay, bisexual, transgender, queer (or questioning) youth and those with mental health disorders, problem behaviors, previous suicidality, self-harm, and gender (female). A person-centered approach emphasizing connectedness and bully-free school environments should be a priority focus for schools, health professionals, and public health policymakers.

Why we need to pursue both universal and targeted prevention to reduce the incidence of affective and psychotic disorders: Systematic review and meta-analysis

The effectiveness of universal preventive approaches in reducing the incidence of affective/psychotic disorders is unclear. We therefore aimed to synthesise the available evidence from randomised controlled trials. For studies reporting change in prevalence, we simulated all possible scenarios for the proportion of individuals with the disorder at baseline and at follow-up to exclude them. We then combined these data with studies directly measuring incidence and conducted random effects meta-analysis with relative risk (RR) to estimate the incidence in the intervention group compared to the control group. Eighteen studies (k=21 samples) were included investigating the universal prevention of depression in 66,625 individuals. No studies were available investigating universal prevention on the incidence of bipolar/psychotic disorders. 63 % of simulated scenarios showed a significant preventive effect on reducing the incidence of depression (k=9 - 19, RR=0.75-0.94, 95 %CIs=0.55-0.87,0.93-1.15, p=0.007-0.246) but did not survive sensitivity analyses. There is some limited evidence for the effectiveness of universal interventions for reducing the incidence of depression but not for bipolar/psychotic disorders.

The association of adverse childhood experiences with long-term outcomes of psychosis: a 21-year prospective cohort study after a first episode of psychosis

BACKGROUND

Evidence suggests a possible relationship between exposure to childhood adversity (CA) and functional impairment in psychosis. However, the impact of CA on long-term outcomes of psychotic disorders remains poorly understood.

METHODS

Two hundred and forty-three patients were assessed at their first episode of psychosis for CA and re-assessed after a mean of 21 years of follow-up for several outcome domains, including symptoms, functioning, quality of life, cognitive performance, neurological dysfunction, and comorbidity. The unique predictive ability of CA exposure for outcomes was examined using linear regression analysis controlling for relevant confounders, including socioeconomic status, family risk of schizophrenia, and obstetric complications.

RESULTS

There were 54% of the patients with a documented history of CA at mild or higher levels. CA experiences were more prevalent and severe in schizophrenia than in other psychotic disorders (p < 0.001). Large to very large effect sizes were observed for CA predicting most role functioning variables and negative symptoms (ΔR2 between 0.105 and 0.181). Moderate effect sizes were observed for positive symptoms, personal functioning, impaired social cognition, impaired immediate verbal learning, poor global cognition, internalized stigma, poor personal recovery, and drug abuse severity (ΔR2 between 0.040 and 0.066). A dose-response relationship was observed between levels of CA and severity of outcome domains.

CONCLUSION

Our results suggest a strong and widespread link between early adversity exposure and outcomes of psychotic disorders. Awareness of the serious long-term consequences of CA should encourage better identification of those at risk and the development of effective interventions.

Sexually transmitted infections, sexual life and risk behaviours of people living with schizophrenia: systematic review and meta-analysis

BACKGROUND

Sexually transmitted infections (STIs), along with sexual health and behaviour, have received little attention in schizophrenia patients.

AIMS

To systematically review and meta-analytically characterise the prevalence of STIs and sexual risk behaviours among schizophrenia patients.

METHOD

Web of Science, PubMed, BIOSIS, KCI-Korean Journal Database, MEDLINE, Russian Science Citation Index, SciELO and Cochrane Central Register were systematically searched from inception to 6 July 2023. Studies reporting on the prevalence or odds ratio of any STI or any outcome related to sexual risk behaviours among schizophrenia samples were included. PRISMA/MOOSE-compliant (CRD42023443602) random-effects meta-analyses were used for the selected outcomes. Q-statistics, I2 index, sensitivity analyses and meta-regressions were used. Study quality and publication bias were assessed.

RESULTS

Forty-eight studies (N = 2 459 456) reporting on STI prevalence (including 15 allowing for calculation of an odds ratio) and 33 studies (N = 4255) reporting on sexual risk behaviours were included. Schizophrenia samples showed a high prevalence of STIs and higher risks of HIV (odds ratio = 2.11; 95% CI 1.23-3.63), hepatitis C virus (HCV, odds ratio = 4.54; 95% CI 2.15-961) and hepatitis B virus (HBV; odds ratio = 2.42; 95% CI 1.95-3.01) infections than healthy controls. HIV prevalence was higher in Africa compared with other continents and in in-patient (rather than out-patient) settings. Finally, 37.7% (95% CI 31.5-44.4%) of patients were sexually active; 35.0% (95% CI 6.6-59.3%) reported consistent condom use, and 55.3% (95% CI 25.0-82.4%) maintained unprotected sexual relationships.

CONCLUSIONS

Schizophrenia patients have high prevalence of STIs, with several-fold increased risks of HIV, HBV and HCV infection compared with the general population. Sexual health must be considered as an integral component of care.

Approaches for measuring cumulative childhood adversity: A study of youth from 5 sub-Saharan African countries

BACKGROUND

Adverse childhood experiences (ACEs) include forms of abuse, neglect, and household stressors that are potentially early life traumatic experiences. A summed integer count of ACEs is often used to examine cumulative childhood adversity (CCA) but has limitations.

OBJECTIVES

The current study tests two additional methods for measuring CCA using large samples of youth in low- and middle-income countries.

PARTICIPANTS AND SETTING

Pooled data were analyzed from a multi-country, nationally representative sample of youth aged 18-24 years (N = 11,498) who completed the Violence Against Children and Youth Surveys (VACS) in Lesotho, Cote d'Ivoire, Kenya, Namibia, and Mozambique.

METHODS

ACE exposures included: physical, sexual, and emotional violence; witnessing interparental violence; witnessing community violence; orphanhood. CCA was operationalized using an ACE score, ACE impact (standardized regression coefficients from outcome severity), and ACE exposure context (household; intimate partner; peer; community). Associations between CCA with mental distress (MD) were examined by sex using p ≤ 0.05 as the significance level.

RESULTS

Exposure to ≥3 ACEs was associated with MD (p < 0.05) for both sexes. Among females, all contexts contributed to MD except peer ACEs (p < 0.05). Among males, household and community ACEs contributed to MD. High-impact ACEs were associated with MD both sexes. ACE context was the best-fitting model for these data.

CONCLUSIONS

The challenges operationalizing CCA warrant continued research to ensure adversity type, severity, and context lead to validly assessing ACEs impact on child wellbeing.

Taking stock to move forward: Where the field of developmental psychopathology might be heading

In this paper, dedicated to Dante Cicchetti's contributions and enduring influence, we explore the prospective directions of developmental psychopathology. Our focus centers on key domains where Cicchetti's significant achievements have continually shaped our evolving thinking about psychological development. These domains include (a) the concepts of equifinality and multifinality, along with the challenges in predicting developmental trajectories, (b) the imperative to integrate wider sociocultural viewpoints into developmental psychopathology frameworks, (c) the interplay of genetic and environmental influences in developmental courses, (d) the significance of mental state language, and (e) the progress, or its absence, in the development of prevention and intervention tactics for children, adolescents, and their caregivers. While many of our forecasts regarding the future of developmental psychopathology may not materialize, we maintain optimistic that the essential ideas presented will influence the research agenda in this field and contribute to its growth over the next fifty years.

A web-enabled, school-based intervention for bullying prevention (LINKlusive): a cluster randomised trial

Background

There is a need for more sustainable interventions and for assessing the effectiveness of school-based universal anti-bullying programmes in vulnerable populations. We assessed the efficacy of a multicomponent, web-enabled, school-based intervention that aims to improve school climate and reduce bullying (LINKlusive) relative to conventional practices (control condition).

Methods

We conducted a cluster randomised controlled trial in primary and secondary schools in Madrid, Spain. The primary outcome measure was peer-reported bullying victimisation after the 12-week intervention (study endpoint). We analysed data using longitudinal mixed-effects models. The trial was registered with the ISRCTN registry (15719015).

Findings

We included 20 schools (10 in each group); 6542 students participated at baseline; 6403 were assessed at study endpoint. After the intervention, there was a statistically significant reduction in bullying victimisation in both the intervention (OR 0.61, 95% CI [0.41, 0.90]) and control groups (OR 0.69, 95% CI [0.51, 0.92]), with no evidence of differences in the whole sample (OR 0.89, 95% CI [0.58, 1.36]; aOR 0.89, 95% CI [0.58, 1.37]). Subgroup analyses showed a statistically significant effect of LINKlusive on bullying victimisation in primary education (aOR 0.68, 95% CI [0.47, 0.98]). In students with peer-reported bullying victimisation at baseline, LINKlusive showed a statistically significant effect on depression (-1.43, 95% CI [-2.46, -0.40], adjusted standardised mean difference (SMD) -0.41) and quality of life (2.18, 95% CI [0.80, 3.56], adjusted SMD 0.45).

Interpretation

LINKlusive could be effective in reducing bullying victimisation in primary school students. Sustainable whole-school interventions to promote mental health and reduce risk factors are warranted to improve outcomes in young people, especially in the early years of education.

Funding

Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation.

School bullying in children and adolescents with neurodevelopmental and psychiatric conditions: a systematic review and meta-analysis

BACKGROUND

Bullying is a common form of violence among children and adolescents. Young people with neurodevelopmental or psychiatric conditions might have an increased risk of bullying victimisation and perpetration. We aimed to assess the odds of bullying involvement and its association with mental health measures in these populations.

METHODS

In this systematic review and meta-analysis, we searched PubMed, ERIC, Psychology and Behavioural Sciences Collection, Web of Science Core Collection, PsycArticles, and PsycInfo databases from inception up to Aug 8, 2023, and included articles reporting data on bullying outcomes of current bullying (within the past year) among children and adolescents (aged 4-17 years) with a diagnosis of a neurodevelopmental or psychiatric condtion provided by a health professional. Bullying type was classified as traditional (physical, verbal, or relational) or as cyberbullying (intentional and repeated harm inflicted through electronic devices and social media), and bullying involvement was classified as victimisation, perpetration, and perpetration-victimisation. Mental health measures were collected and the associations with bullying involvement assessed. We used random-effects meta-analyses to estimate prevalence and odds ratios (ORs) for bullying involvement. Heterogeneity was assessed using the I2 statistic, and publication bias was tested with Egger's regression. This study is registered with PROSPERO, CRD42021235043.

FINDINGS

We included 212 studies in the meta-analysis. The total sample comprised 126 717 cases (mean age 12·34 years [SD 1·82], 37·6% girls) and 504 806 controls (12·5 years [SD 1·86], 47·6% girls). For traditional bullying, the pooled prevalence was 42·2% (95% CI 39·6-44·9) for victimisation, 24·4% (22·6-26·3) for perpetration, and 14·0% (11·4-17·1) for perpetration-victimisation. For cyberbullying, the prevalence was 21·8% (16·0-28·9) for victimisation, 19·6% (13·4-27·7) for perpetration, and 20·7% (8·4-42·6) for perpetration-victimisation. Compared with controls, young people with neurodevelopmental or psychiatric conditions were more likely to be involved in traditional and cyberbullying as a victim (OR 2·85 [95% CI 2·62-3·09] and 2·07 [1·63-2·61]), perpetrator (2·42 [2·20-2·66] and 1·91 [1·60-2·28]), and perpetrator-victim (3·66 [2·83-4·74] and 1·85 [1·05-3·28]). Bullying involvement was associated with higher scores in mental health measures in young people with neurodevelopmental or psychiatric conditions, particularly internalising symptoms and externalising symptoms.

INTERPRETATION

Our study underscores bullying involvement as a prevalent risk factor in young people with neurodevelopmental or psychiatric conditions that might add to their disease burden through its negative effects on mental health. Interventions targeting these vulnerable populations are warranted to improve their mental health and their future social integration.

FUNDING

Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation, and Consorcio Centro de Investigación Biomédica en Red.

The schizophrenia syndrome, circa 2024: What we know and how that informs its nature

With new data about different aspects of schizophrenia being continually generated, it becomes necessary to periodically revisit exactly what we know. Along with a need to review what we currently know about schizophrenia, there is an equal imperative to evaluate the construct itself. With these objectives, we undertook an iterative, multi-phase process involving fifty international experts in the field, with each step building on learnings from the prior one. This review assembles currently established findings about schizophrenia (construct, etiology, pathophysiology, clinical expression, treatment) and posits what they reveal about its nature. Schizophrenia is a heritable, complex, multi-dimensional syndrome with varying degrees of psychotic, negative, cognitive, mood, and motor manifestations. The illness exhibits a remitting and relapsing course, with varying degrees of recovery among affected individuals with most experiencing significant social and functional impairment. Genetic risk factors likely include thousands of common genetic variants that each have a small impact on an individual's risk and a plethora of rare gene variants that have a larger individual impact on risk. Their biological effects are concentrated in the brain and many of the same variants also increase the risk of other psychiatric disorders such as bipolar disorder, autism, and other neurodevelopmental conditions. Environmental risk factors include but are not limited to urban residence in childhood, migration, older paternal age at birth, cannabis use, childhood trauma, antenatal maternal infection, and perinatal hypoxia. Structural, functional, and neurochemical brain alterations implicate multiple regions and functional circuits. Dopamine D-2 receptor antagonists and partial agonists improve psychotic symptoms and reduce risk of relapse. Certain psychological and psychosocial interventions are beneficial. Early intervention can reduce treatment delay and improve outcomes. Schizophrenia is increasingly considered to be a heterogeneous syndrome and not a singular disease entity. There is no necessary or sufficient etiology, pathology, set of clinical features, or treatment that fully circumscribes this syndrome. A single, common pathophysiological pathway appears unlikely. The boundaries of schizophrenia remain fuzzy, suggesting the absence of a categorical fit and need to reconceptualize it as a broader, multi-dimensional and/or spectrum construct.

Distress Symptoms of Old Age and Mild Cognitive Impairment are Two Distinct Dimensions in Older Adults Without Major Depression

Background

Studies in old adults showed bidirectional interconnections between amnestic mild cognitive impairment (aMCI) and affective symptoms and that adverse childhood experiences (ACE) may affect both factors. Nevertheless, these associations may be confined to older adults with clinical depression.

Aim

To delineate the relationship between clinical symptoms of aMCI and affective symptoms in older adults without major depression (MDD) or dysfunctions in activities of daily living (ADL).

Methods

This case-control study recruited 61 participants with aMCI (diagnosed using Petersen's criteria) and 59 older adults without aMCI and excluded subjects with MDD and ADL dysfunctions.

Results

We uncovered 2 distinct dimensions, namely distress symptoms of old age (DSOA), comprising affective symptoms, perceived stress and neuroticism, and mild cognitive dysfunctions, comprising episodic memory test scores, the total Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores. A large part of the variance (37.9%) in DSOA scores was explained by ACE, negative life events (health and financial problems), a subjective feeling of cognitive decline, and education (all positively). ACE and NLE have a highly significant impact on the DSOA score and are not associated with aMCI or its severity. Cluster analysis showed that the diagnosis of aMCI is overinclusive because some subjects with DSOA symptoms may be incorrectly classified as aMCI.

Conclusion

The clinical impact is that clinicians should carefully screen older adults for DSOA after excluding MDD. DSOA might be misinterpreted as aMCI.

THC improves behavioural schizophrenia-like deficits that CBD fails to overcome: a comprehensive multilevel approach using the Poly I:C maternal immune activation

Prenatal infections and cannabis use during adolescence are well-recognized risk factors for schizophrenia. As inflammation and oxidative stress (OS) contribute to this disorder, anti-inflammatory drugs have been proposed as potential therapies. This study aimed to evaluate the association between delta-9-tetrahydrocannabinol (THC) and schizophrenia-like abnormalities in a maternal immune activation (MIA) model. Additionally, we assessed the preventive effect of cannabidiol (CBD), a non-psychotropic/anti-inflammatory cannabinoid. THC and/or CBD were administered to Saline- and MIA-offspring during periadolescence. At adulthood, THC-exposed MIA-offspring showed significant improvements in sensorimotor gating deficits. Structural and metabolic brain changes were evaluated by magnetic resonance imaging, revealing cortical shrinkage in Saline- and enlargement in MIA-offspring after THC-exposure. Additionally, MIA-offspring displayed enlarged ventricles and decreased hippocampus, which were partially reverted by both cannabinoids. CBD prevented THC-induced reduction in the corpus callosum, despite affecting white matter structure. Post-mortem studies revealed detrimental effects of THC, including increased inflammation and oxidative stress. CBD partially reverted these pro-inflammatory alterations and modulated THC's effects on the endocannabinoid system. In conclusion, contrary to expectations, THC exhibited greater behavioural and morphometric benefits, despite promoting a pro-inflammatory state that CBD partially reverted. Further research is needed to elucidate the underlying mechanisms involved in the observed benefits of THC.

Biobehavioral Interactions between Endocannabinoid and Hypothalamicpituitary- adrenal Systems in Psychosis: A Systematic Review

BACKGROUND

The diathesis-stress paradigm and the cannabinoid-hypothesis have been proposed as possible pathophysiological models of schizophrenia. However, they have historically been studied independently of each other.

OBJECTIVE

This PRISMA 2020-compliant systematic review aimed at reappraising the interplay between the hypothalamic-pituitary-adrenal (HPA) axis and the endocannabinoid (eCB) system in psychosis- spectrum disorder risk and outcome.

METHODS

All pathophysiological and outcome clinical studies, concomitantly evaluating the two systems in psychosis-spectrum disorder risk and different stages of illness, were gathered from electronic databases (Pubmed, Web of Science, and Scopus), and discussed.

RESULTS

41 eligible outputs were extracted, focusing on at least a biological measure (9 HPA-related studies: 4 eCB-interventional, 1 HPA-interventional, 1 both HPA-interventional and non-interventional, 3 non-interventional; 2 eCB-related studies: non-interventional), environmental measures only (29 studies: 1 eCB- interventional, 28 non-interventional), and genetic measures (1 study: non-interventional). Independent contributions of aberrancies in the two systems to the physiopathology and outcome of psychosis were confirmed. Also, concomitant alterations in the two systems, either genetically defined (e.g., CNR1 genetic variation), biologically determined (e.g., dysfunctional HPA axis or endocannabinoid signaling), or behaviorally imputed (e.g., cannabis use, stress exposure, and response), were consistently reported in psychosis. Further, a complex biobehavioral perturbation was revealed not only within each system (e.g., cannabis use affecting the eCB tone, stress exposure affecting the HPA axis), but also across the two systems (e.g., THC affecting the HPA axis, childhood trauma affecting the endocannabinoid signaling).

CONCLUSION

There is a need to concomitantly study the two systems' mechanistic contribution to psychosis in order to establish more refined biological relevance.

The Translational Future of Stress Neurobiology and Psychosis Vulnerability: A Review of the Evidence

Psychosocial stress is a well-established risk factor for psychosis, yet the neurobiological mechanisms underlying this relationship have yet to be fully elucidated. Much of the research in this field has investigated hypothalamic-pituitary-adrenal (HPA) axis function and immuno-inflammatory processes among individuals with established psychotic disorders. However, as such studies are limited in their ability to provide knowledge that can be used to develop preventative interventions, it is important to shift the focus to individuals with increased vulnerability for psychosis (i.e., high-risk groups). In the present article, we provide an overview of the current methods for identifying individuals at high-risk for psychosis and review the psychosocial stressors that have been most consistently associated with psychosis risk. We then describe a network of interacting physiological systems that are hypothesised to mediate the relationship between psychosocial stress and the manifestation of psychotic illness and critically review evidence that abnormalities within these systems characterise highrisk populations. We found that studies of high-risk groups have yielded highly variable findings, likely due to (i) the heterogeneity both within and across high-risk samples, (ii) the diversity of psychosocial stressors implicated in psychosis, and (iii) that most studies examine single markers of isolated neurobiological systems. We propose that to move the field forward, we require well-designed, largescale translational studies that integrate multi-domain, putative stress-related biomarkers to determine their prognostic value in high-risk samples. We advocate that such investigations are highly warranted, given that psychosocial stress is undoubtedly a relevant risk factor for psychotic disorders.

Adverse childhood experiences and psychological functioning among women with schizophrenia or bipolar disorder: population-based study

BACKGROUND

Adverse childhood experiences (ACEs) are well-known risk factors for schizophrenia and bipolar disorder.

AIMS

The aim was to study the associations between specific ACEs and psychological functioning in women with schizophrenia or bipolar disorder.

METHOD

Among 29 367 women (mean age 44 years) from the Icelandic Stress-And-Gene-Analysis (SAGA) study, 534 (1.8%, mean age 40) reported having been diagnosed with schizophrenia or bipolar disorder, which were combined to 'severe mental disorders'. Participants reported on 13 types of ACEs, childhood deprivation and psychological functioning (defined as coping ability and current symptoms of depression, anxiety and sleep disturbances). Adjusted Poisson regression calculated prevalence ratios (PRs) between ACEs and severe mental disorders. Linear regression assessed the association between ACEs and psychological functioning among women with a severe mental disorder.

RESULTS

Women with a severe mental disorder reported more ACEs (mean 4.57, s.d. = 2.82) than women without (mean 2.51, s.d. = 2.34) in a dose-dependent manner (fully-adjusted PR = 1.23 per ACE, 95% CI 1.20-1.27). After mutual adjustment for other ACEs, emotional abuse, sexual abuse, mental illness of a household member, emotional neglect, bullying and collective violence were associated with severe mental disorders. Among women with severe mental disorders, a higher number of ACEs was associated with increased symptom burden of depression (β = 2.79, 95% CI = 1.19-4.38) and anxiety (β = 2.04, 95% CI = 0.99-3.09) including poorer sleep quality (β = 0.83, 95% CI = 0.07-1.59). Findings were similar for schizophrenia and bipolar disorder separately.

CONCLUSION

Women with schizophrenia or bipolar disorder show a strong history of ACEs, which may interfere with their psychological functioning and, therefore, need to be addressed as part of their treatment, for example, with trauma-focused psychotherapy.

Incidence, prevalence, and global burden of schizophrenia - data, with critical appraisal, from the Global Burden of Disease (GBD) 2019

Schizophrenia substantially contributes to the burden of mental disorders. Schizophrenia's burden and epidemiological estimates in some countries have been published, but updated estimates of prevalence, incidence, and schizophrenia-related disability at the global level are lacking. Here, we present the data from and critically discuss the Global Burden of Diseases, Injuries, and Risk Factors Study data, focusing on temporal changes in schizophrenia's prevalence, incidence, and disability-adjusted life years (DALYs) globally. From 1990 to 2019, schizophrenia raw prevalence (14.2 to 23.6 million), incidence (941,000 to 1.3 million), and DALYs (9.1 to 15.1 million) increased by over 65%, 37%, and 65% respectively, while age-standardized estimates remained stable globally. In countries with high socio-demographic index (SDI), both prevalence and DALYs increased, while in those with low SDI, the age-standardized incidence decreased and DALYs remained stable. The male/female ratio of burden of schizophrenia has remained stable in the overall population over the past 30 years (i.e., M/F = 1.1), yet decreasing from younger to older age groups (raw prevalence in females higher than males after age 65, with males having earlier age of onset, and females longer life expectancy). Results of this work suggest that schizophrenia's raw prevalence, incidence, and burden have been increasing since 1990. Age-adjusted estimates did not reduce. Schizophrenia detection in low SDI countries is suboptimal, and its prevention/treatment in high SDI countries should be improved, considering its increasing prevalence. Schizophrenia sex ratio inverts throughout the lifespan, suggesting different age of onset and survival by sex. However, prevalence and burden estimates for schizophrenia are probably underestimated. GBD does not account for mortality from schizophrenia (and other mental disorders, apart from anorexia nervosa).

Sex/gender differences in the associations between adverse childhood experiences and intimate partner violence with mental disorders

Sex and gender differences exist in mental and substance use disorders (MSUDs). Studies examining the moderating effects of sex/gender on MSUDs may help understand these differences. This national study explored whether sex/gender moderated (1) the associations between adverse childhood experience (ACEs; i.e., child abuse, child neglect, and child household dysfunction) and intimate partner violence (IPV) with MSUDs and (2) more associations with past year than lifetime MSUDs or mental (i.e., mood disorder, anxiety disorder, and posttraumatic stress disorder) than substance use disorders (i.e., alcohol use disorder and nicotine dependence). Data was used from participants in the National Epidemiologic Survey on Alcohol and Related Conditions. Logistic regression tested the main effects of ACEs, IPV, and sex/gender on five, past-year and lifetime MSUDs along with the ACE-sex/gender and IPV-sex/gender interactions. Sex/gender moderated 60% of the ACEs-MSUD and IPV-MSUD associations and more associations with lifetime (54%) than past year MSUDs (46%) and substance use (94%) than mental disorders (38%). For nearly half of the moderated associations, ACEs and IPV were associated with greater odds of MSUDs for males. Males who experienced IPV had greater odds of lifetime mood, anxiety, and alcohol use disorders than females. This study advances sex and gender informed research.

Association between non-medical cannabis legalization and emergency department visits for cannabis-induced psychosis

A major public health concern of cannabis legalization is that it may result in an increase in psychotic disorders. We examined changes in emergency department (ED) visits for cannabis-induced psychosis following the legalization and subsequent commercialization (removal of restrictions on retail stores and product types) of non-medical cannabis in Ontario, Canada (population of 14.3 million). We used health administrative data containing the cause of all ED visits to examine changes over three periods; 1) pre-legalization (January 2014-September 2018); 2) legalization with restrictions (October 2018 - February 2020); and 3) commercialization (March 2020 - September 2021). We considered subgroups stratified by age and sex and examined cocaine- and methamphetamine-induced psychosis ED visits as controls. During our study, there were 6300 ED visits for cannabis-induced psychosis. The restricted legalization period was not associated with changes in rates of ED visits for cannabis-induced psychosis relative to pre-legalization. The commercialization period was associated with an immediate increase in rates of ED visits for cannabis-induced psychosis (IRR 1.30, 95% CI 1.02-1.66) and no gradual monthly change; immediate increases were seen only for youth above (IRR 1.63, 1.27-2.08, ages 19-24) but not below (IRR 0.73 95%CI 0.42-1.28 ages, 15-18) the legal age of purchase, and similar for men and women. Commercialization was not associated with changes in rates of ED visits for cocaine- or methamphetamine-induced psychosis. This suggests that legalization with store and product restrictions does not increase ED visits for cannabis-induced psychosis. In contrast, cannabis commercialization may increase cannabis-induced psychosis presentations highlighting the importance of preventive measures in regions considering legalization.

Effect modification of an effective transdiagnostic cognitive behavioral psychotherapy in youths with common mental health problems: Secondary analyses of the randomized mind-my-mind trial

Mind My Mind (MMM) cognitive behavioral therapy (CBT) manualized treatment is effective in the management of common emotional and behavioral mental health problems in youth, yet not all individuals respond satisfactorily to treatment. This study explored potential effect modifiers, i.e., baseline factors associated with a differential treatment effect. We conducted secondary effect modifier analyses with MMM trial data, which involved randomization of 396 youths aged 6-16 years to either MMM CBT treatment (9-13 sessions) or management as usual in local community settings. We examined sociodemographic- (sex, age, family composition, ethnicity, parental education, and income) and clinical variables (mental disorders and duration of mental health problems) as potential effect modifiers of the a) change in parent-rated impact of mental health problems measured by the Strengths and Difficulties Questionnaire (SDQ) or b) response (reduction of ≥1 on SDQ-impact). In intention-to-treat analyses, superior treatment (net) benefits from the MMM intervention were found among youths who met criteria for any mental disorder at baseline (-1.25 [95%CI: -1.67;-0.82]) compared to youths that did not meet diagnostic criteria (-0.22 [95%CI:-1.09;0.65]). Comorbidity vs no comorbidity (-1.84 [95%CI:-2.58;-1.10] vs -0.72 [95%CI:-1.15;-0.29]) and longer duration of untreated mental health problems, i.e., more vs less than 6 months (-1.16 [95%CI:-1.55;-0.78] vs 0.43 [95%CI:-1.01;1.86]) were also associated with superior treatment benefits. The sociodemographic factors were not associated with differential treatment effects in the intention-to-treat analyses. These findings suggest that community-based programs like the MMM are well-suited for youths with substantial mental health problems. Clinical Trials Identifier: NCT03535805.

Balancing risks and benefits of cannabis use: umbrella review of meta-analyses of randomised controlled trials and observational studies

OBJECTIVE

To systematically assess credibility and certainty of associations between cannabis, cannabinoids, and cannabis based medicines and human health, from observational studies and randomised controlled trials (RCTs).

DESIGN

Umbrella review.

DATA SOURCES

PubMed, PsychInfo, Embase, up to 9 February 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Systematic reviews with meta-analyses of observational studies and RCTs that have reported on the efficacy and safety of cannabis, cannabinoids, or cannabis based medicines were included. Credibility was graded according to convincing, highly suggestive, suggestive, weak, or not significant (observational evidence), and by GRADE (Grading of Recommendations, Assessment, Development and Evaluations) (RCTs). Quality was assessed with AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews 2). Sensitivity analyses were conducted.

RESULTS

101 meta-analyses were included (observational=50, RCTs=51) (AMSTAR 2 high 33, moderate 31, low 32, or critically low 5). From RCTs supported by high to moderate certainty, cannabis based medicines increased adverse events related to the central nervous system (equivalent odds ratio 2.84 (95% confidence interval 2.16 to 3.73)), psychological effects (3.07 (1.79 to 5.26)), and vision (3.00 (1.79 to 5.03)) in people with mixed conditions (GRADE=high), improved nausea/vomit, pain, spasticity, but increased psychiatric, gastrointestinal adverse events, and somnolence among others (GRADE=moderate). Cannabidiol improved 50% reduction of seizures (0.59 (0.38 to 0.92)) and seizure events (0.59 (0.36 to 0.96)) (GRADE=high), but increased pneumonia, gastrointestinal adverse events, and somnolence (GRADE=moderate). For chronic pain, cannabis based medicines or cannabinoids reduced pain by 30% (0.59 (0.37 to 0.93), GRADE=high), across different conditions (n=7), but increased psychological distress. For epilepsy, cannabidiol increased risk of diarrhoea (2.25 (1.33 to 3.81)), had no effect on sleep disruption (GRADE=high), reduced seizures across different populations and measures (n=7), improved global impression (n=2), quality of life, and increased risk of somnolence (GRADE=moderate). In the general population, cannabis worsened positive psychotic symptoms (5.21 (3.36 to 8.01)) and total psychiatric symptoms (7.49 (5.31 to 10.42)) (GRADE=high), negative psychotic symptoms, and cognition (n=11) (GRADE=moderate). In healthy people, cannabinoids improved pain threshold (0.74 (0.59 to 0.91)), unpleasantness (0.60 (0.41 to 0.88)) (GRADE=high). For inflammatory bowel disease, cannabinoids improved quality of life (0.34 (0.22 to 0.53) (GRADE=high). For multiple sclerosis, cannabinoids improved spasticity, pain, but increased risk of dizziness, dry mouth, nausea, somnolence (GRADE=moderate). For cancer, cannabinoids improved sleep disruption, but had gastrointestinal adverse events (n=2) (GRADE=moderate). Cannabis based medicines, cannabis, and cannabinoids resulted in poor tolerability across various conditions (GRADE=moderate). Evidence was convincing from observational studies (main and sensitivity analyses) in pregnant women, small for gestational age (1.61 (1.41 to 1.83)), low birth weight (1.43 (1.27 to 1.62)); in drivers, car crash (1.27 (1.21 to 1.34)); and in the general population, psychosis (1.71 (1.47 to 2.00)). Harmful effects were noted for additional neonatal outcomes, outcomes related to car crash, outcomes in the general population including psychotic symptoms, suicide attempt, depression, and mania, and impaired cognition in healthy cannabis users (all suggestive to highly suggestive).

CONCLUSIONS

Convincing or converging evidence supports avoidance of cannabis during adolescence and early adulthood, in people prone to or with mental health disorders, in pregnancy and before and while driving. Cannabidiol is effective in people with epilepsy. Cannabis based medicines are effective in people with multiple sclerosis, chronic pain, inflammatory bowel disease, and in palliative medicine but not without adverse events.

STUDY REGISTRATION

PROSPERO CRD42018093045.

FUNDING

None.

Meta-analytic prevalence of comorbid mental disorders in individuals at clinical high risk of psychosis: the case for transdiagnostic assessment

Comorbid mental disorders in subjects at clinical high risk for psychosis (CHR-P) may impact preventive care. We conducted a PRISMA/MOOSE-compliant systematic meta-analysis, searching PubMed/PsycInfo up to June 21st, 2021 for observational studies/randomized controlled trials reporting on comorbid DSM/ICD-mental disorders in CHR-P subjects ( protocol ). The primary and secondary outcomes were baseline and follow-up prevalence of comorbid mental disorders. We also explored the association of comorbid mental disorders compared with CHR-P versus psychotic/non-psychotic control groups, their impact on baseline functioning and transition to psychosis. We conducted random-effects meta-analyses, meta-regression, and assessed heterogeneity/publication bias/quality (Newcastle Ottawa Scale, NOS). We included 312 studies (largest meta-analyzed sample = 7834, any anxiety disorder, mean age = 19.98 (3.40), females = 43.88%, overall NOS > 6 in 77.6% of studies). The prevalence was 0.78 (95% CI = 0.73-0.82, k = 29) for any comorbid non-psychotic mental disorder, 0.60 (95% CI = 0.36-0.84, k = 3) for anxiety/mood disorders, 0.44 (95% CI = 0.39-0.49, k = 48) for any mood disorders, 0.38 (95% CI = 0.33-0.42, k = 50) for any depressive disorder/episode, 0.34 (95% CI = 0.30-0.38, k = 69) for any anxiety disorder, 0.30 (95% CI 0.25-0.35, k = 35) for major depressive disorders, 0.29 (95% CI, 0.08-0.51, k = 3) for any trauma-related disorder, 0.23 (95% CI = 0.17-0.28, k = 24) for any personality disorder, and <0.23 in other mental disorders (I2 > 50% in 71.01% estimates). The prevalence of any comorbid mental disorder decreased over time (0.51, 95% CI = 0.25-0.77 over 96 months), except any substance use which increased (0.19, 95% CI = 0.00-0.39, k = 2, >96 months). Compared with controls, the CHR-P status was associated with a higher prevalence of anxiety, schizotypal personality, panic, and alcohol use disorders (OR from 2.90 to 1.54 versus without psychosis), a higher prevalence of anxiety/mood disorders (OR = 9.30 to 2.02) and lower prevalence of any substance use disorder (OR = 0.41, versus psychosis). Higher baseline prevalence of alcohol use disorder/schizotypal personality disorder was negatively associated with baseline functioning (beta from -0.40 to -0.15), while dysthymic disorder/generalized anxiety disorder with higher functioning (beta 0.59 to 1.49). Higher baseline prevalence of any mood disorder/generalized anxiety disorder/agoraphobia (beta from -2.39 to -0.27) was negatively associated with transition to psychosis. In conclusion, over three-quarters of CHR-P subjects have comorbid mental disorders, which modulate baseline functionig and transition to psychosis. Transdiagnostic mental health assessment should be warranted in subjects at CHR-P.

A 40-year study of child maltreatment over the early life course predicting psychiatric morbidity, using linked birth cohort and administrative health data: protocol for the Childhood Adversity and Lifetime Morbidity (CALM) study

BACKGROUND

Child maltreatment is a major public health issue worldwide. Retrospective studies show a strong association between self-reported child maltreatment and poor mental and physical health problems. Prospective studies that use reports to statutory agencies are less common, and comparisons of self- and agency-reported abuse in the same cohort even rarer.

AIMS

This project will link state-wide administrative health data with prospective birth cohort data (N = 7223) from Brisbane in Queensland, Australia (including notifications to child protection agencies), to compare psychiatric outcomes in adulthood of agency- and self-reported child maltreatment while minimising attrition bias.

METHOD

We will compare people with all forms of self- and agency-reported child maltreatment to the rest of the cohort, adjusting for confounding in logistic, Cox or multiple regression models based on whether outcomes are categorical or continuous. Outcomes will be hospital admissions, emergency department presentations or community/out-patient contacts for ICD-10 psychiatric diagnoses, suicidal ideation and self-harm as recorded in the relevant administrative databases.

CONCLUSIONS

This study will track the life course outcomes of adults after having experienced child maltreatment, and so provide an evidence-based understanding of the long-term health and behavioural consequences of child maltreatment. It will also consider health outcomes that are particularly relevant for adolescents and young adults, especially in relation to prospective notifications to statutory agencies. Additionally, it will identify the overlap and differences in outcome for two different sources of child maltreatment identification in the same cohort.

Extended and replicated white matter changes in obesity: Voxel-based and region of interest meta-analyses of diffusion tensor imaging studies

Introduction

Obesity has become a global public health issue, which impacts general health and the brain. Associations between obesity and white matter microstructure measured using diffusion tensor imaging have been under reviewed, despite a relatively large number of individual studies. Our objective was to determine the association between obesity and white matter microstructure in a large general population sample.

Methods

We analyzed location of brain white matter changes in obesity using the Anisotropic Effect Size Seed-based d Mapping (AES-SDM) method in a voxel-based meta-analysis, with validation in a region of interest (ROI) effect size meta-analysis. Our sample included 21 742 individuals from 51 studies.

Results

The voxel-based spatial meta-analysis demonstrated reduced fractional anisotropy (FA) with obesity in the genu and splenium of the corpus callosum, middle cerebellar peduncles, anterior thalamic radiation, cortico-spinal projections, and cerebellum. The ROI effect size meta-analysis replicated associations between obesity and lower FA in the genu and splenium of the corpus callosum, middle cerebellar peduncles. Effect size of obesity related brain changes was small to medium.

Discussion

Our findings demonstrate obesity related brain white matter changes are localized rather than diffuse. Better understanding the brain correlates of obesity could help identify risk factors, and targets for prevention or treatment of brain changes.