Empirical evidence suggests that people use cannabis to ameliorate anxiety and depressive symptoms, yet cannabis also acutely worsens psychosis and affective symptoms. However, the temporal relationship between cannabis use, anxiety and depressive symptoms and psychotic experiences (PE) in longitudinal studies is unclear. This may be informed by examination of mutually mediating roles of cannabis, anxiety and depressive symptoms in the emergence of PE.

Data were derived from the second longitudinal Netherlands Mental Health Survey and Incidence Study. Mediation analysis was performed to examine the relationship between cannabis use, anxiety/depressive symptoms and PE, using KHB logit in STATA while adjusting for age, sex and education status.

Cannabis use was found to mediate the relationship between preceding anxiety, depressive symptoms and later PE incidence, but the indirect contribution of cannabis use was small (for anxiety: % of total effect attributable to cannabis use = 1.00%; for depression: % of total effect attributable to cannabis use = 1.4%). Interestingly, anxiety and depressive symptoms were found to mediate the relationship between preceding cannabis use and later PE incidence to a greater degree (% of total effect attributable to anxiety = 17%; % of total effect attributable to depression = 37%).

This first longitudinal cohort study examining the mediational relationship between cannabis use, anxiety/depressive symptoms and PE, shows that there is a bidirectional relationship between cannabis use, anxiety/depressive symptoms and PE. However, the contribution of anxiety/depressive symptoms as a mediator was greater than that of cannabis.

A transdiagnostic and contextual framework of ‘clinical characterization’, combining clinical, psychopathological, sociodemographic, etiological, and other personal contextual data, may add clinical value over and above categorical algorithm-based diagnosis.

Prediction of need for care and health care outcomes was examined prospectively as a function of the contextual clinical characterization diagnostic framework in a prospective general population cohort (n = 6646 at baseline), interviewed four times between 2007 and 2018 (NEMESIS-2). Measures of need, service use, and use of medication were predicted as a function of any of 13 DSM-IV diagnoses, both separately and in combination with clinical characterization across multiple domains: social circumstances/demographics, symptom dimensions, physical health, clinical/etiological factors, staging, and polygenic risk scores (PRS). Effect sizes were expressed as population attributable fractions.

Any prediction of DSM-diagnosis in relation to need and outcome in separate models was entirely reducible to components of contextual clinical characterization in joint models, particularly the component of transdiagnostic symptom dimensions (a simple score of the number of anxiety, depression, mania, and psychosis symptoms) and staging (subthreshold, incidence, persistence), and to a lesser degree clinical factors (early adversity, family history, suicidality, slowness at interview, neuroticism, and extraversion), and sociodemographic factors. Clinical characterization components in combination predicted more than any component in isolation. PRS did not meaningfully contribute to any clinical characterization model.

A transdiagnostic framework of contextual clinical characterization is of more value to patients than a categorical system of algorithmic ordering of psychopathology.

Although hallucinations have been studied in terms of prevalence and its associations with psychopathology and functional impairment, very little is known about sensory modalities other than auditory (i.e. haptic, visual and olfactory), as well the incidence of hallucinations, factors predicting incidence and subsequent course.

We examined the incidence, course and risk factors of hallucinatory experiences across different modalities in two unique prospective general population cohorts in the same country using similar methodology and with three interview waves, one over the period 1996–1999 (NEMESIS) and one over the period 2007–2015 (NEMESIS-2).

In NEMESIS-2, the yearly incidence of self-reported visual hallucinations was highest (0.33%), followed by haptic hallucinations (0.31%), auditory hallucinations (0.26%) and olfactory hallucinations (0.23%). Rates in NEMESIS-1 were similar (respectively: 0.35%, 0.26%, 0.23%, 0.22%). The incidence of clinician-confirmed hallucinations was approximately 60% of the self-reported rate. The persistence rate of incident hallucinations was around 20–30%, increasing to 40–50% for prevalent hallucinations. Incident hallucinations in one modality were very strongly associated with occurrence in another modality (median OR = 59) and all modalities were strongly associated with delusional ideation (median OR = 21). Modalities were approximately equally strongly associated with the presence of any mental disorder (median OR = 4), functioning, indicators of help-seeking and established environmental risk factors for psychotic disorder.

Hallucinations across different modalities are a clinically relevant feature of non-psychotic disorders and need to be studied in relation to each other and in relation to delusional ideation, as all appear to have a common underlying mechanism.

The present study was conducted to examine (i) prenatal and postnatal patterns of growth in relation to the risk of later mental health problems in children and (ii) the possible mediating effect of these patterns of growth in the association between parental socioeconomic status (SES) and children’s mental health.

The present study is part of a blinded, matched case control study, involving a retrospective analysis of prospectively collected data from routine examinations at community health services for children and adolescents. The sample comprised 80 patients, referred between the age of 6–13 years to the Community Mental Health Centre in Maastricht, and 320 matched population controls.

Children coming from unemployed families weighed less at birth, but postnatal growth was not associated with this or other indicators of SES. Although children using mental health care were somewhat smaller at birth, there was no evidence that leanness during childhood was a risk factor for the development of mental health problems.

The present results showed some evidence for the impact of intrauterine development on children’s mental health problems. In addition, neither prenatal nor postnatal physical growth were on the pathway between parental SES and children’s mental health problems.

The aim of the study was to examine the potential contribution of exposure to bullying and adverse life events to the development of psychopathology in adolescents, and possible effect modification by neighbourhood social capital.

Two waves of routine, longitudinal, standard health examinations at local community paediatric health services, pertaining to 749 adolescents living in Maastricht (The Netherlands) who were attending second grade of secondary school (age 13/14 years) and approximately 2 years later going to the fourth grade (age 15/16 years), were analysed. A self-report questionnaire was used, including measures of psychopathology and two measures of negative life experiences, exposure to bullying and adverse life events, that were available for both age groups and subjected to (multilevel) regression analysis.

Exposure to bullying in the past school-year as well as the experience of adverse life events over a 12 month period, at the age of 13/14 years, predicted an increase in psychopathology at follow-up. Exposure to bullying was associated with the development of hyperactivity and emotional problems, while the experience of adverse life events predicted the development of conduct problems. Family-related adverse events had greatest effect sizes. Effects of bullying and adverse life events were not moderated by neighbourhood social capital.

Negative life experiences impact on liability to psychopathology in adolescents independent of the wider social environment.

Contemporary models of psychosis implicate the importance of affective dysregulation and cognitive factors (e.g. biases and schemas) in the development and maintenance of psychotic symptoms, but studies testing proposed mechanisms remain limited. This study, uniquely using a prospective design, investigated whether the jumping to conclusions (JTC) reasoning bias contributes to psychosis progression and persistence.

Data were derived from the second Netherlands Mental Health Survey and Incidence Study (NEMESIS-2). The Composite International Diagnostic Interview and an add-on instrument were used to assess affective dysregulation (i.e. depression, anxiety and mania) and psychotic experiences (PEs), respectively. The beads task was used to assess JTC bias. Time series analyses were conducted using data from T1 and T2 (N = 8666), excluding individuals who reported high psychosis levels at T0.

Although the prospective design resulted in low statistical power, the findings suggest that, compared to those without symptoms, individuals with lifetime affective dysregulation were more likely to progress from low/moderate psychosis levels (state of ‘aberrant salience’, one or two PEs) at T1 to high psychosis levels (‘frank psychosis’, three or more PEs or psychosis-related help-seeking behaviour) at T2 if the JTC bias was present [adj. relative risk ratio (RRR): 3.8, 95% confidence interval (CI) 0.8–18.6, p = 0.101]. Similarly, the JTC bias contributed to the persistence of high psychosis levels (adj. RRR: 12.7, 95% CI 0.7–239.6, p = 0.091).

We found some evidence that the JTC bias may contribute to psychosis progression and persistence in individuals with affective dysregulation. However, well-powered prospective studies are needed to replicate these findings.

Evidence suggests that cannabis use, childhood adversity, and urbanicity, in interaction with proxy measures of genetic risk, may facilitate onset of psychosis in the sense of early affective dysregulation becoming ‘complicated’ by, first, attenuated psychosis and, eventually, full-blown psychotic symptoms.

Data were derived from three waves of the second Netherlands Mental Health Survey and Incidence Study (NEMESIS-2). The impact of environmental risk factors (cannabis use, childhood adversity, and urbanicity) was analyzed across severity levels of psychopathology defined by the degree to which affective dysregulation was ‘complicated’ by low-grade psychotic experiences (‘attenuated psychosis’ – moderately severe) and, overt psychotic symptoms leading to help-seeking (‘clinical psychosis’ – most severe). Familial and non-familial strata were defined based on family history of (mostly) affective disorder and used as a proxy for genetic risk in models of family history × environmental risk interaction.

In proxy gene–environment interaction analysis, childhood adversity and cannabis use, and to a lesser extent urbanicity, displayed greater-than-additive risk if there was also evidence of familial affective liability. In addition, the interaction contrast ratio grew progressively greater across severity levels of psychosis admixture (none, attenuated psychosis, clinical psychosis) complicating affective dysregulation.

Known environmental risks interact with familial evidence of affective liability in driving the level of psychosis admixture in states of early affective dysregulation in the general population, constituting an affective pathway to psychosis. There is interest in decomposing family history of affective liability into the environmental and genetic components that underlie the interactions as shown here.

The jumping to conclusions (JTC) reasoning bias and decreased working memory performance (WMP) are associated with psychosis, but associations with affective disturbances (i.e. depression, anxiety, mania) remain inconclusive. Recent findings also suggest a transdiagnostic phenotype of co-occurring affective disturbances and psychotic experiences (PEs). This study investigated whether JTC bias and decreased WMP are associated with co-occurring affective disturbances and PEs.

Data were derived from the second Netherlands Mental Health Survey and Incidence Study (NEMESIS-2). Trained interviewers administered the Composite International Diagnostic Interview (CIDI) at three time points in a general population sample (N = 4618). The beads and digit-span task were completed to assess JTC bias and WMP, respectively. CIDI was used to measure affective disturbances and an add-on instrument to measure PEs.

Compared to individuals with neither affective disturbances nor PEs, the JTC bias was more likely to occur in individuals with co-occurring affective disturbances and PEs [moderate psychosis (1–2 PEs): adjusted relative risk ratio (RRR) 1.17, 95% CI 0.98–1.41; and high psychosis (3 or more PEs or psychosis-related help-seeking behaviour): adjusted RRR 1.57, 95% CI 1.19–2.08], but not with affective disturbances and PEs alone, whereas decreased WMP was more likely in all groups. There was some evidence of a dose–response relationship, as JTC bias and decreased WMP were more likely in individuals with affective disturbances as the level of PEs increased or help-seeking behaviour was reported.

The findings suggest that JTC bias and decreased WMP may contribute to a transdiagnostic phenotype of co-occurring affective disturbances and PEs.

El presente estudio se realizó para examinar (i) los patrones prenatal y postnatal de crecimiento en relatión con el riesgo de problemas de salud mental posteriores en los niños y (ii) el posible efecto mediador de estos patrones de crecimiento en la asociación entre el nivel socioeconómico de los padres (NSE) y la salud mental de los hijos.

El presente estudio es parte de un estudio ciego de casos y controles emparejados que implicaba un análisis retrospectivo de datos recogidos prospectivamente a partir de los reconocimientos habituales en los servicios de salud comunitaria para niños y adolescentes. La muestra constaba de 80 pacientes, derivados a los 6-13 años de edad al Centro de Salud Mental Comunitaria en Maastricht, y 320 controles de la poblacion emparejados.

Los niños procedentes de familias sin empleo pesaban menos al nacer, pero el crecimiento postnatal no se asociaba con éste u otros indicadores del NSE. Aunque los niños que usaban la asistencia sanitaria mental eran algo más pequeños en el nacimiento, no había datos de que la delgadez durante la infancia fuera un factor de riesgo para el desarrollo de problemas de salud mental.

Los presentes resultados mostraban algunos datos para las repercusiones del desarrollo intrauterino en los problemas de salud mental de los niños. Además, ni el crecimiento físico prenatal ni el postnatal estaban en la vía entre el NSE de los padres y los problemas de salud mental de los hijos.

Neighbourhood characteristics may influence the risk of psychosis, independently of their individual-level equivalents.

To examine these issues in a multi-level model of schizophrenia incidence.

Cases of schizophrenia, incident between 1986 and 1997, were identified from the Maastricht Mental Health Case Register. A multi-level analysis was conducted to examine the independent effects of individual-level and neighbourhood-level variables in 35 neighbourhoods.

Independent of individual-level single and divorced marital status, an effect of the proportion of single persons and proportion of divorced persons in a neighbourhood was apparent (per 1% increase respectively: RR=1.02; 95% CI 1.00–1.03; and RR=1.12, 95% CI 1.04–1.2.1). Single marital status interacted with the neighbourhood proportion of single persons, the effect being stronger in neighbourhoods with fewer single-person households.

The neighbourhood environment modifies the individual risk for schizophrenia. Premorbid vulnerability resulting in single marital status may be more likely to progress to overt disease in an environment with a higher perceived level of social isolation.