Prevalence, incidence, and persistence of psychotic experiences in the general population: results of a 9-year follow-up study.

BACKGROUND: Psychotic experiences (PEs) frequently occur and are associated with a range of negative health outcomes. Prospective studies on PEs are scarce, and to date no study investigated PE prevalence, incidence, persistence, their risk indicators, and psychiatric comorbidity, in one dataset. Furthermore, most studies are based on self-report, and it is unclear how this compares to clinical interviews. METHODS: Data are used from the Netherlands Mental Health Survey and Incidence Study-2 (NEMESIS-2), a psychiatric cohort study among a representative sample of adults (baseline characteristics: N = 6646; 49.6% female; 18-64 years). Results are presented for self-reported and clinically validated PEs. Associations are assessed for mental disorders, socio-demographic, vulnerability, physical health, and substance use factors. RESULTS: Based on self-report, at baseline 16.5% of respondents had at least one PE in their lifetime, of those, 30.1% also reported a PE at 3-year follow-up. 4.8% had a first PE at 3-year follow up. The 3-year prevalence of PE was associated with almost all studied risk indicators. Generally, the strongest associations were found for mental health disorders. Prevalence and incidence rates were two to three times higher in self-report than in clinical interview but results on associated factors were similar. CONCLUSIONS: Validated prevalence and incidence estimates of PE are substantially lower than self-reported figures but results on associated factors were similar. Therefore, future studies on associations of PEs can rely on relatively inexpensive self-reports of PEs. The associations between PE and mental disorders underline the importance of assessment of PE in general practice.

Bidirectional relationships between cannabis use, anxiety and depressive symptoms in the mediation of the association with psychotic experience: further support for an affective pathway to psychosis.

BACKGROUND: 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. METHODS: 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. RESULTS: 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%). CONCLUSION: 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.

Context v. algorithm: evidence that a transdiagnostic framework of contextual clinical characterization is of more clinical value than categorical diagnosis.

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

Age- and sex-specific associations between risk scores for schizophrenia and self-reported health in the general population.

PURPOSE: The health correlates of polygenic risk (PRS-SCZ) and exposome (ES-SCZ) scores for schizophrenia may vary depending on age and sex. We aimed to examine age- and sex-specific associations of PRS-SCZ and ES-SCZ with self-reported health in the general population. METHODS: Participants were from the population-based Netherlands Mental Health Survey and Incidence Study-2 (NEMESIS-2). Mental and physical health were measured with the 36-item Short Form Survey 4 times between 2007 and 2018. The PRS-SCZ and ES-SCZ were respectively calculated from common genetic variants and exposures (cannabis use, winter birth, hearing impairment, and five childhood adversity categories). Moderation by age and sex was examined in linear mixed models. RESULTS: For PRS-SCZ and ES-SCZ analyses, we included 3099 and 6264 participants, respectively (age range 18-65 years; 55.7-56.1% female). Age and sex did not interact with PRS-SCZ. Age moderated the association between ES-SCZ and mental (interaction: p = 0.02) and physical health (p = 0.0007): at age 18, + 1.00 of ES-SCZ was associated with - 0.10 of mental health and - 0.08 of physical health, whereas at age 65, it was associated with - 0.21 and - 0.23, respectively (all units in standard deviations). Sex moderated the association between ES-SCZ and physical health (p < .0001): + 1.00 of ES-SCZ was associated with - 0.19 of physical health among female and - 0.11 among male individuals. CONCLUSION: There were larger associations between higher ES-SCZ and poorer health among female and older individuals. Accounting for these interactions may increase ES-SCZ precision and help uncover populational determinants of environmental influences on health.

Evidence, and replication thereof, that molecular-genetic and environmental risks for psychosis impact through an affective pathway.

BACKGROUND: There is evidence that environmental and genetic risk factors for schizophrenia spectrum disorders are transdiagnostic and mediated in part through a generic pathway of affective dysregulation. METHODS: We analysed to what degree the impact of schizophrenia polygenic risk (PRS-SZ) and childhood adversity (CA) on psychosis outcomes was contingent on co-presence of affective dysregulation, defined as significant depressive symptoms, in (i) NEMESIS-2 (n = 6646), a representative general population sample, interviewed four times over nine years and (ii) EUGEI (n = 4068) a sample of patients with schizophrenia spectrum disorder, the siblings of these patients and controls. RESULTS: The impact of PRS-SZ on psychosis showed significant dependence on co-presence of affective dysregulation in NEMESIS-2 [relative excess risk due to interaction (RERI): 1.01, p = 0.037] and in EUGEI (RERI = 3.39, p = 0.048). This was particularly evident for delusional ideation (NEMESIS-2: RERI = 1.74, p = 0.003; EUGEI: RERI = 4.16, p = 0.019) and not for hallucinatory experiences (NEMESIS-2: RERI = 0.65, p = 0.284; EUGEI: -0.37, p = 0.547). A similar and stronger pattern of results was evident for CA (RERI delusions and hallucinations: NEMESIS-2: 3.02, p < 0.001; EUGEI: 6.44, p < 0.001; RERI delusional ideation: NEMESIS-2: 3.79, p < 0.001; EUGEI: 5.43, p = 0.001; RERI hallucinatory experiences: NEMESIS-2: 2.46, p < 0.001; EUGEI: 0.54, p = 0.465). CONCLUSIONS: The results, and internal replication, suggest that the effects of known genetic and non-genetic risk factors for psychosis are mediated in part through an affective pathway, from which early states of delusional meaning may arise.

Identification of Latent Alcohol Use Groups and Transitions over Time Using a 9-Year Follow-Up Study in the Adult General Population.

INTRODUCTION: Studies investigating latent alcohol use groups and transitions of these groups over time are scarce, while such knowledge could facilitate efficient use of screening and preventive interventions for groups with a high risk of problematic alcohol use. Therefore, the present study examines the characteristics, transitions, and long-term stability of adult alcohol use groups and explores some of the possible predictors of the transitions. METHODS: Data were used from the baseline, 3-, 6-, and 9-year follow-up waves of the Netherlands Mental Health Survey and Incidence Study-2 (NEMESIS-2), a representative study of Dutch adults aged 18-64 at baseline (N = 6,646; number of data points: 20,574). Alcohol consumption, alcohol use disorder (AUD), and mental disorders were assessed with the Composite International Diagnostic Interview 3.0. Latent Markov Modelling was used to identify latent groups based on high average alcohol consumption (HAAC) and AUD and to determine transition patterns of people between groups over time (stayers vs. movers). RESULTS: The best fitting model resulted in four latent groups: one nonproblematic group (91%): no HAAC, no AUD; and three problematic alcohol use groups (9%): HAAC, no AUD (5%); no HAAC, often AUD (3%); and HAAC and AUD (1%). HAAC, no AUD was associated with a high mean age (55 years) and low educational level (41%), and no HAAC, often AUD with high proportions of males (78%) and people with high educational level (46%). Eighty-seven percent of all respondents - mostly people with no HAAC, no AUD - stayed in their original group during the whole 9-year period. Among movers, people in a problematic alcohol use group (HAAC and/or AUD) mostly transitioned to another problematic alcohol use group and not to the nonproblematic alcohol use group (no HAAC, no AUD). Explorative analyses suggested that lack of physical activity possibly plays a role in transitions both from and to problematic alcohol use groups over time. CONCLUSION: The detection of three problematic alcohol use groups - with transitions mostly between the different problematic alcohol use groups and not to the group without alcohol problems - points to the need to explicitly address both alcohol consumption and alcohol-related problems (AUD criteria) in screening measures and interventions in order not to miss and to adequately treat all problematic alcohol users. Moreover, explorative findings suggest that prevention measures should also include physical activity.

Evidence for an interrelated cluster of Hallucinatory experiences in the general population: an incidence study.

BACKGROUND: 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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 jumping to conclusions reasoning bias as a cognitive factor contributing to psychosis progression and persistence: findings from NEMESIS-2.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Duration of anxiety disorder and its associated risk indicators: Results of a longitudinal study of the general population.

BACKGROUND: Data on episode duration of anxiety disorders are required for informing patients and for disease management, but such data from population studies are lacking. METHODS: Three-year longitudinal data were used from the Netherlands Mental Health Survey and Incidence Study-2, a psychiatric epidemiological cohort study among the general adult population (N = 6646). Respondents with a new (first or recurrent) anxiety disorder were selected (n = 158). DSM-IV diagnoses were assessed with the Composite International Diagnostic Interview; the Life Chart Interview assessed episode duration and recovery rates. RESULTS: Among those with anxiety disorder, median episode duration was 7.5 months and mean duration was 15.2 months. 38.8% had not recovered at 12 months and 30.1% not at 36 months. Longer duration was associated with older age, not having a paid job, higher neuroticism, more physical disorders, and worse physical functioning. CONCLUSIONS: Also, in the general population, anxiety disorder has a rather chronic course. After 12 months the cumulative recovery rate flattened. To prevent and manage chronicity, timely treatment, and chronic disease management are required. The risk indicators found may help to identify individuals with an anxiety disorder at risk for chronicity.

Longitudinal bidirectional associations between internalizing mental disorders and cardiometabolic disorders in the general adult population.

PURPOSE: This prospective population-based study investigated whether having any internalizing mental disorder (INT) was associated with the presence and onset of any cardiometabolic disorder (CM) at 3-year follow-up; and vice versa. Furthermore, we examined whether observed associations differed when using longer time intervals of respectively 6 and 9 years. METHODS: Data were used from the four waves (baseline and 3-, 6- and 9-year follow-up) of the Netherlands Mental Health Survey and Incidence Study-2, a prospective study of a representative cohort of adults. At each wave, the presence and first onset of INT (i.e. any mood or anxiety disorder) were assessed with the Composite International Diagnostic Interview 3.0; the presence and onset of CM (i.e. hypertension, diabetes, heart disease, and stroke) were based on self-report. Multilevel logistic autoregressive models were controlled for previous-wave INT and CM, respectively, and sociodemographic, clinical, and lifestyle covariates. RESULTS: Having any INT predicted both the presence (OR 1.28, p = 0.029) and the onset (OR 1.46, p = 0.003) of any CM at the next wave (3-year intervals). Having any CM was not significantly related to the presence of any INT at 3-year follow-up, while its association with the first onset of any INT reached borderline significance (OR 1.64, p = 0.06), but only when examining 6-year intervals. CONCLUSIONS: Our findings indicate that INTs increase the risk of both the presence and the onset of CMs in the short term, while CMs may increase the likelihood of the first onset of INTs in the longer term. Further research is needed to better understand the mechanisms underlying the observed associations.

The Bidirectional Relationship Between Debts and Common Mental Disorders: Results of a longitudinal Population-Based Study.

Researchers and politicians have regularly expressed their worries about a widening of socioeconomic inequalities in physical and mental health. Debts have been relatively understudied as a specific aspect of socioeconomic disadvantage contributing to poor mental health. This study examines the bidirectional association between debts and common mental disorders (CMDs) in the adult population of the Netherlands. Data were obtained from the second ('baseline') and third (3-year follow-up) wave of the Netherlands Mental Health Survey and Incidence Study-2, a representative cohort of adults. Questions were asked about debts and difficulty in repaying debts in the past 12 months. The answers were combined into one variable: no debts, easy, difficult, and very difficult to pay back debts. Twelve-month CMDs were assessed with the Composite International Diagnostic Interview version 3.0. Increasing levels of difficulty in repaying debts predicted onset of CMD at follow-up in those without 12-month CMD at baseline, and persistence of CMD at follow-up in those with 12-month CMD at baseline. Conversely, CMD was not linked to onset of debts at follow-up in those without 12-month debts at baseline, but was associated with persistence of difficulty to pay back debts at follow-up in those with 12-month debts at baseline. These associations remained significant after adjustment for baseline sociodemographic variables, negative life events and physical health. Health professionals and debt counsellors should pay more attention to patients' debts and clients' mental health respectively in order to refer those with financial or mental health problems to the appropriate services.

The bidirectional relationship between loneliness and common mental disorders in adults: findings from a longitudinal population-based cohort study.

PURPOSE: Limited longitudinal population-based research exists on the bidirectional association between loneliness and common mental disorders (CMDs). Using 3-year follow-up data, this study examined whether loneliness among adults increases the risk for onset and persistence of mild-moderate or severe CMD; and whether mild-moderate or severe CMD is a risk factor for onset and persistence of loneliness. METHODS: Data were used from the second ('baseline') and third (3-year follow-up) waves of the Netherlands Mental Health Survey and Incidence Study-2, a prospective study of a representative cohort of adults aged 18-64 years. Twelve-month CMDs and their severity were assessed with the Composite International Diagnostic Interview 3.0, and current loneliness using the De Jong Gierveld Loneliness Scale. Multivariate analyses were controlled for several potential confounders. RESULTS: Loneliness predicted onset of severe CMD at follow-up in adults without CMDs at baseline, and increased risk for persistent severe CMD at follow-up in those with CMD at baseline. Conversely, severe CMD predicted onset of loneliness at follow-up in non-lonely adults at baseline, but was not associated with persistent loneliness at follow-up in lonely adults at baseline. Observed associations remained significant after controlling for perceived social support at baseline, except for the relationship between loneliness and persistent severe CMD. No longitudinal relationships were observed between loneliness and mild-moderate CMD. CONCLUSIONS: Attention should be paid to loneliness, both in adults with and without CMD. Further research is needed to better understand the mechanisms underlying the observed associations between loneliness and CMDs to develop successful interventions.

Interaction between environmental and familial affective risk impacts psychosis admixture in states of affective dysregulation.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Reasoning bias, working memory performance and a transdiagnostic phenotype of affective disturbances and psychotic experiences in the general population.

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

The interplay of psychosis and victimisation across the life course: a prospective study in the general population.

PURPOSE: Psychosis has been associated with adult victimisation. However, it remains unclear whether psychosis predicts incident adult victimisation, or whether adult victimisation predicts incident psychosis. Furthermore, a moderating effect of childhood victimisation on the association between psychosis and adult victimisation has not been investigated. METHODS: The longitudinal association between baseline psychotic experiences and six-year incidence of adult victimisation was assessed in a prospective general population cohort of 6646 adults using logistic regression analysis. The association between baseline adult victimisation and six-year incidence of psychotic experiences was examined as well. Furthermore, the moderating effect of childhood victimisation on these bidirectional associations was analysed. RESULTS: Psychotic experiences and childhood victimisation were both associated with an increased risk of incident adult victimisation. However, this was through competing pathways, as suggested by a negative interaction between psychotic experiences and childhood victimisation. Baseline adult victimisation and childhood victimisation both independently increased the risk of incident psychotic experiences, but there was no interaction between adult victimisation and childhood victimisation. CONCLUSIONS: Psychosis and victimisation are interconnected throughout the life course. Childhood victimisation is connected to psychosis through two pathways: one direct and one indirect through adult victimisation. In individuals without childhood victimisation, psychosis and adult victimisation bidirectionally impact on each other.

Semantics bias in cross-national comparative analyses: is it good or bad to have "fair" health?

The Health Behavior in School-aged Children is a cross-national study collecting data on social and health indicators on adolescents in 43 countries. The study provides comparable data on health behaviors and health outcomes through the use of a common protocol, which have been a back bone of the study sine its initiation in 1983. Recent years, researchers within the study have noticed a questionable comparability on the widely used item on self-rated health. One of the four response categories to the item "Would you say your health is….?" showed particular variation, as the response category "Fair" varied from 20 % in Latvia and Moldova to 3-4 % in Bulgaria and Macedonia. A qualitative mini-survey of the back-translations showed that the response category "Fair" had a negative slant in 25 countries, a positive slant in 10 countries and was considered neutral in 9 countries. This finding indicates that there are what may be called semantic issues affecting comparability in international studies, since the same original word (in an English original) is interpreted differently across countries and cultures. The paper test and discuss a few possible explanations to this, however, only leaving to future studies to hold a cautious approach to international comparisons if working with the self-rated health item with four response categories.

Prevalence rates of borderline personality disorder symptoms: a study based on the Netherlands Mental Health Survey and Incidence Study-2.

BACKGROUND: Despite increasing knowledge of the prevalence of borderline personality disorder (BPD) in the general population, and rising awareness of mental disorders both as a categorical and a dimensional construct, research is still lacking on the prevalence of the number of BPD symptoms and their associated consequences, such as comorbidity, disability, and the use of mental health services) in the general population. METHODS: Data were obtained from the second wave of the Netherlands Mental Health Survey and Incidence Study-2 (N = 5303), a nationally representative face-to-face survey of the general population. BPD symptoms were measured by means of questions from the International Personality Disorder Examination. Comorbidity of common mental disorders was assessed with the Composite International Diagnostic Interview version 3.0. RESULTS: Of the total population studied, 69.9 % reported no BPD symptoms, while 25.2 % had 1-2 symptoms, 3.8 % had 3-4 symptoms, and 1.1 % had ≥ 5 BPD symptoms. The number of BPD symptoms reported was found to be positively associated with not living with a partner, having no paid job, and/or having a comorbid mood, anxiety or substance use disorder. Even after adjustment for sociodemographic characteristics and comorbidity, the number of BPD symptoms turned out to be uniquely associated with disability. It also showed a positive relationship with using services for dealing with mental health problems, although this relationship was strongly affected by the presence of comorbid disorders. CONCLUSIONS: Because even a relatively low number of BPD symptoms appears to be associated with psychiatric comorbidity and functional disability, not only full-blown BPD but also subthreshold levels of BPD symptoms need to be identified in clinical practice and research.

Exposure to environmental factors increases connectivity between symptom domains in the psychopathology network.

BACKGROUND: We investigated to what degree environmental exposure (childhood trauma, urbanicity, cannabis use, and discrimination) impacts symptom connectivity using both continuous and categorical measures of psychopathology. METHODS: Outcomes were continuous symptom dimensions of self-reported psychopathology using the Self-report Symptom Checklist-90-R in 3021 participants from The Early Developmental Stages of the Psychopathology (EDSP) study and binary DSM-III-R categories of mental disorders and a binary measure of psychotic symptoms in 7076 participants from The Netherlands Mental Health Survey and Incidence Study (NEMESIS-1). For each symptom dimension in the EDSP and mental disorder in the NEMESIS-1 as the dependent variable, regression analyses were carried out including each of the remaining symptom dimensions/mental disorders and its interaction with cumulative environmental risk load (the sum score of environmental exposures) as independent variables. RESULTS: All symptom dimensions in the EDSP and related diagnostic categories in the NEMESIS-1 were strongly associated with each other, and environmental exposures increased the degree of symptom connectivity in the networks in both cohorts. CONCLUSIONS: Our findings showing strong connectivity across symptom dimensions and related binary diagnostic constructs in two independent population cohorts provide further evidence for the conceptualization of psychopathology as a contextually sensitive network of mutually interacting symptoms.

Low functional status as a predictor of incidence of emotional disorders in the general population.

PURPOSE: To examine the association between baseline functional status and any emotional disorder at follow-up, after controlling for potential confounders. The effect modification of previous mental disorders and physical conditions was assessed. METHODS: Data are from the Netherlands Mental Health Survey and Incidence Study-2, a representative population-based, 3-year longitudinal study completed in 2012. Individuals at risk of a new or a recurrent emotional disorder were selected at baseline (n = 4,574). The appearance of any emotional disorder between waves, assessed with the Composite International Diagnostic Interview 3.0, was the outcome. Functional status at baseline was assessed with the physical (PCS) and mental component summary (MCS) of the Short Form-36 Health Survey version 1 and with the number of disability days collected with the World Health Organization Disability Assessment Scale II. Multivariable logistic regression models adjusted by socio-demographic and lifestyle factors were fitted. Interaction terms between previous mental disorders or physical conditions with the predictors were tested. RESULTS: At baseline, 12.1 % had low PCS score, 5.9 % had low MCS score and 30.3 % reported any disability days. The incidence of emotional disorders in 3 years was 9.1 % [95 % confidence interval (95 % CI) 8.1-10.3]. Having low PCS or low MCS at baseline [PCS adjusted OR (aOR) 1.51, p value = 0.02; MCS aOR 1.90, p = 0.002] or reporting more than 15 disability days (aOR 1.63, p = 0.035) was significantly associated with 3-year incidence of emotional disorders. Having a previous mental disorder modified the relationship between MCS and incidence. Among those with a low MCS score, a previous mental disorder considerably increased the risk of incident emotional disorders (aOR 2.72, p = <0.001). CONCLUSIONS: Low functional status is an independent risk factor for developing emotional disorders in the general population. Appropriate identification followed by early intervention may contribute to reduce their associated burden.