Clinically decisive (dis)agreement in multidisciplinary team assessment of esophageal squamous cell carcinoma; a prospective, national, multicenter study.

BACKGROUND: Decisions regarding tumor staging, operability, resectability, and treatment strategy in patients with esophageal cancer are made at multidisciplinary team (MDT) conferences. We aimed to assess interobserver agreement from four national MDT conferences and whether this would have a clinical impact. METHODS: A total of 20 patients with esophageal cancer were included across all four upper gastrointestinal (GI) cancer centers. Fully anonymized patient data were distributed among the MDT conferences which decided on TNM category, resectability, operability, curability, and treatment strategy blinded to each other's decisions. The interobserver agreement was expressed as both the raw observer agreement and with Krippendorff's α values. Finally, a case-by-case evaluation was performed to determine if disagreement would have had a clinical impact. RESULTS: A total of 80 MDT evaluations were available for analysis. A moderate to near-perfect observer agreement of 79.2%, 55.8%, and 82.5% for TNM category was observed, respectively. Substantial agreement for resectability and moderate agreement for curability were found. However, an only fair agreement was observed for the operability category. The treatment strategies had a slight agreement which corresponded to disagreement having a clinical impact in 12 patients. CONCLUSIONS: Esophageal cancer MDT conferences had an acceptable interobserver agreement on resectability and TM categories; however, the operability assessment had a high level of disagreement. Consequently, the agreement on treatment strategy was reduced with a potential clinical impact. In future MDT conferences, emphasis should be on prioritizing the relevant information being readily available (operability, T & M categories) to minimize the risk of disagreement in the assessments and treatment strategies, and thus, delayed or suboptimal treatment.

Comorbidity within mental disorders: a comprehensive analysis based on 145 990 survey respondents from 27 countries.

AIMS: Epidemiological studies indicate that individuals with one type of mental disorder have an increased risk of subsequently developing other types of mental disorders. This study aimed to undertake a comprehensive analysis of pair-wise lifetime comorbidity across a range of common mental disorders based on a diverse range of population-based surveys. METHODS: The WHO World Mental Health (WMH) surveys assessed 145 990 adult respondents from 27 countries. Based on retrospectively-reported age-of-onset for 24 DSM-IV mental disorders, associations were examined between all 548 logically possible temporally-ordered disorder pairs. Overall and time-dependent hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models. Absolute risks were estimated using the product-limit method. Estimates were generated separately for men and women. RESULTS: Each prior lifetime mental disorder was associated with an increased risk of subsequent first onset of each other disorder. The median HR was 12.1 (mean = 14.4; range 5.2-110.8, interquartile range = 6.0-19.4). The HRs were most prominent between closely-related mental disorder types and in the first 1-2 years after the onset of the prior disorder. Although HRs declined with time since prior disorder, significantly elevated risk of subsequent comorbidity persisted for at least 15 years. Appreciable absolute risks of secondary disorders were found over time for many pairs. CONCLUSIONS: Survey data from a range of sites confirms that comorbidity between mental disorders is common. Understanding the risks of temporally secondary disorders may help design practical programs for primary prevention of secondary disorders.

Impact of severe mental illness on cancer stage at diagnosis and subsequent mortality: A population-based register study.

BACKGROUND: Excess mortality in individuals with severe mental illness (SMI) is often explained by physical comorbidity and suboptimal healthcare. Cancer is a prevalent cause of death, and tumour stage at diagnosis is a strong predictor of mortality. We aimed to study cancer incidence, disease stage at diagnosis and subsequent mortality in individuals with SMI compared to individuals without SMI. METHODS: The entire Danish population was followed in 1978-2013 using nationwide registries. Cancer incidence and subsequent mortality stratified by disease stage were compared in individuals with and without SMI. Cox regression was used to estimate incidence rate ratios (IRR) and mortality rate ratios (MRR). Cancer was examined overall and grouped by major aetiological factors. RESULTS: The overall cancer incidence rate was lower in males with SMI than in males without SMI; IRR = 0.89 (95% CI: 0.85-0.94), but rates were similar in females with SMI and without SMI; IRR = 1.03 (95% CI: 0.99-1.07). The overall mortality rate was higher in individuals with SMI than those without; MRR = 1.56 (95% CI: 1.48-1.64) for males and MRR = 1.49 (95% CI: 1.43-1.56) for females. Incidence rates and mortality rates showed similar estimates when stratified by tumour stage and aetiology. CONCLUSIONS: We found lower cancer incidence in males with SMI compared to males without SMI and similar incidence in the two groups of women. Higher subsequent mortality was found in both sexes with SMI. The excess mortality was not explained by more advanced stages of cancer; future studies should evaluate the effect of cancer treatment and rehabilitation.

The iPSYCH2012 case-cohort sample: new directions for unravelling genetic and environmental architectures of severe mental disorders.

The Integrative Psychiatric Research (iPSYCH) consortium has established a large Danish population-based Case-Cohort sample (iPSYCH2012) aimed at unravelling the genetic and environmental architecture of severe mental disorders. The iPSYCH2012 sample is nested within the entire Danish population born between 1981 and 2005, including 1 472 762 persons. This paper introduces the iPSYCH2012 sample and outlines key future research directions. Cases were identified as persons with schizophrenia (N=3540), autism (N=16 146), attention-deficit/hyperactivity disorder (N=18 726) and affective disorder (N=26 380), of which 1928 had bipolar affective disorder. Controls were randomly sampled individuals (N=30 000). Within the sample of 86 189 individuals, a total of 57 377 individuals had at least one major mental disorder. DNA was extracted from the neonatal dried blood spot samples obtained from the Danish Neonatal Screening Biobank and genotyped using the Illumina PsychChip. Genotyping was successful for 90% of the sample. The assessments of exome sequencing, methylation profiling, metabolome profiling, vitamin-D, inflammatory and neurotrophic factors are in progress. For each individual, the iPSYCH2012 sample also includes longitudinal information on health, prescribed medicine, social and socioeconomic information, and analogous information among relatives. To the best of our knowledge, the iPSYCH2012 sample is the largest and most comprehensive data source for the combined study of genetic and environmental aetiologies of severe mental disorders.

The role of genetic liability in the association of urbanicity at birth and during upbringing with schizophrenia in Denmark.

BACKGROUND: Studies have indicated that the association of urbanicity at birth and during upbringing with schizophrenia may be driven by familial factors such as genetic liability. We used a population-based nested case-control study to assess whether polygenic risk score (PRS) for schizophrenia was associated with urbanicity at birth and at age 15, and to assess whether PRS and parental history of mental disorder together explained the association between urbanicity and schizophrenia. METHODS: Data were drawn from Danish population registries. Cases born since 1981 and diagnosed with schizophrenia between 1994 and 2009 were matched to controls with the same sex and birthdate (1549 pairs). Genome-wide data were obtained from the Danish Neonatal Screening Biobank and PRSs were calculated based on results of a separate, large meta-analysis. RESULTS: Those with higher PRS were more likely reside in the capital compared with rural areas at age 15 [odds ratio (OR) 1.19, 95% confidence interval (CI) 1.01-1.40], but not at birth (OR 1.09, 95% CI 0.95-1.26). Adjustment for PRS produced almost no change in relative risks of schizophrenia associated with urbanicity at birth, but slightly attenuated those for urban residence at age 15. Additional adjustment for parental history led to slight attenuation of relative risks for urbanicity at birth [incidence rate ratio (IRR) for birth in capital = 1.54, 95% CI 1.18-2.02; overall p = 0.016] and further attenuation of relative risks for urbanicity at age 15 (IRR for residence in capital = 1.32, 95% CI 0.97-1.78; overall p = 0.148). CONCLUSIONS: While results regarding urbanicity during upbringing were somewhat equivocal, genetic liability as measured here does not appear to explain the association between urbanicity at birth and schizophrenia.

ASD and schizophrenia show distinct developmental profiles in common genetic overlap with population-based social communication difficulties.

Difficulties in social communication are part of the phenotypic overlap between autism spectrum disorders (ASD) and schizophrenia. Both conditions follow, however, distinct developmental patterns. Symptoms of ASD typically occur during early childhood, whereas most symptoms characteristic of schizophrenia do not appear before early adulthood. We investigated whether overlap in common genetic influences between these clinical conditions and impairments in social communication depends on the developmental stage of the assessed trait. Social communication difficulties were measured in typically-developing youth (Avon Longitudinal Study of Parents and Children, N⩽5553, longitudinal assessments at 8, 11, 14 and 17 years) using the Social Communication Disorder Checklist. Data on clinical ASD (PGC-ASD: 5305 cases, 5305 pseudo-controls; iPSYCH-ASD: 7783 cases, 11 359 controls) and schizophrenia (PGC-SCZ2: 34 241 cases, 45 604 controls, 1235 trios) were either obtained through the Psychiatric Genomics Consortium (PGC) or the Danish iPSYCH project. Overlap in genetic influences between ASD and social communication difficulties during development decreased with age, both in the PGC-ASD and the iPSYCH-ASD sample. Genetic overlap between schizophrenia and social communication difficulties, by contrast, persisted across age, as observed within two independent PGC-SCZ2 subsamples, and showed an increase in magnitude for traits assessed during later adolescence. ASD- and schizophrenia-related polygenic effects were unrelated to each other and changes in trait-disorder links reflect the heterogeneity of genetic factors influencing social communication difficulties during childhood versus later adolescence. Thus, both clinical ASD and schizophrenia share some genetic influences with impairments in social communication, but reveal distinct developmental profiles in their genetic links, consistent with the onset of clinical symptoms.

Differential DNA methylation at birth associated with mental disorder in individuals with 22q11.2 deletion syndrome.

Individuals with 22q11.2 deletion syndrome (DS) have an increased risk of comorbid mental disorders including schizophrenia, attention deficit hyperactivity disorder, depression, as well as intellectual disability. Although most 22q11.2 deletion carriers have the long 3-Mb form of the hemizygous deletion, there remains a large variation in the development and progression of psychiatric disorders, which suggests that alternative factors contribute to the pathogenesis. In this study we investigated whether neonatal DNA methylation signatures in individuals with the 22q11.2 deletion associate with mental disorder later in life. DNA methylation was measured genome-wide from neonatal dried blood spots in a cohort of 164 individuals with 22q11.2DS, including 48 individuals diagnosed with a psychiatric disorder. Among several CpG sites with P-value<10-6, we identified cg23546855 (P-value=2.15 × 10-7) mapping to STK32C to be associated with a later psychiatric diagnosis. Pathway analysis of the top findings resulted in the identification of several Gene Ontology pathways to be significantly enriched (P-value<0.05 after Benjamini-Hochberg correction); among them are the following: neurogenesis, neuron development, neuron projection development, astrocyte development, axonogenesis and axon guidance. In addition, we identified differentially methylated CpG sites in LRP2BP (P-value=5.37 × 10-8) to be associated with intellectual disability (F70-79), in TOP1 (P-value=1.86 × 10-7) with behavioral disorders (F90-98), in NOSIP (P-value=5.12 × 10-8) with disorders of psychological development (F80-89) and in SEMA4B (P-value=4.02 × 10-7) with schizophrenia spectrum disorders (F20-29). In conclusion, our study suggests an association of DNA methylation differences at birth with development of mental disorder later in life in 22q11.2DS individuals.

Risk of eating disorders in immigrant populations.

OBJECTIVE: The risk of certain psychiatric disorders is elevated among immigrants. To date, no population studies on immigrant health have addressed eating disorders. We examined whether risk of eating disorders in first- and second-generation immigrants differs from native-born Danes and Swedes. METHOD: All individuals born 1984-2002 (Danish cohort) and 1989-1999 (Swedish cohort) and residing in the respective country on their 10th birthday were included. They were followed up for the development of eating disorders based on out-patient and in-patient data. RESULTS: The risks of all eating disorder types were lower among first-generation immigrants compared to the native populations: Incidence-rate ratio (95% confidence interval) was 0.39 (0.29, 0.51) for anorexia nervosa, 0.60 (0.42, 0.83) for bulimia nervosa, and 0.62 (0.47, 0.79) for other eating disorders in Denmark and 0.27 (0.21, 0.34) for anorexia nervosa, 0.30 (0.18, 0.51) for bulimia nervosa, and 0.39 (0.32, 0.47) for other eating disorders in Sweden. Likewise, second-generation immigrants by both parents were at lower risk, whereas those with only one foreign-born parent were not. CONCLUSION: The decreased risk of eating disorders among immigrants is opposite to what has been observed for other psychiatric disorders, particularly schizophrenia. Possible explanations include buffering sociocultural factors and underdetection in health care.

COMT Val158Met and MTHFR C677T moderate risk of schizophrenia in response to childhood adversity.

OBJECTIVE: Mesolimbic dopamine sensitization has been hypothesized to be a mediating factor of childhood adversity (CA) on schizophrenia risk. Activity of catechol-O-methyltransferase (COMT) Val158Met increases mesolimbic dopamine signaling and may be further regulated by methylenetetrahydrofolate reductase (MTHFR) C677T. This study investigates the three-way interaction between CA, COMT, and MTHFR. METHODS: We conducted a nested case-control study on individuals born after 1981, linking population-based registers to study the three-way interaction. We included 1699 schizophrenia cases and 1681 controls, and used conditional logistic regression to report incidence rate ratios (IRRs). RESULTS: Childhood adversity was robustly associated with schizophrenia. No main genetic effects were observed. MTHFR C677T increased schizophrenia risk in a dose-dependent manner per MTHFR T allele (P = 0.005) consequent upon CA exposure. After inclusion of the significant (P = 0.03) COMT × MTHFR × CA interaction, the risk was further increased per high-activity COMT Val allele. Hence, exposed COMT Val/Val and MTHFR T/T carriers had an IRR of 2.76 (95% CI, 1.66-4.61). Additional adjustments for ancestry and parental history of mental illness attenuated the results with the interaction being only marginally significant. CONCLUSION: MTHFR C677T and COMT Val158Met interact with CA to increase risk of schizophrenia.

Familial confounding of the association between maternal smoking during pregnancy and internalizing disorders in offspring.

BACKGROUND: Maternal smoking has consistently been associated with multiple adverse childhood outcomes including externalizing disorders. In contrast the association between maternal smoking during pregnancy (MSDP) and internalizing (anxiety and depressive) disorders in offspring has received less investigation. METHOD: We conducted a nationwide cohort study including 957635 individuals born in Denmark between 1991 and 2007. Data on MSDP and diagnoses of depression or anxiety disorders were derived from national registers and patients were followed up from the age of 5 years to the end of 2012. Hazard rate ratios (HRRs) were estimated using stratified Cox regression models. Sibling data were used to disentangle individual- and familial-level effects of MSDP and to control for unmeasured familial confounding. RESULTS: At the population level, offspring exposed to MSDP were at increased risk for both severe depression [HRR 1.29, 95% confidence interval (CI) 1.22-1.36] and severe anxiety disorders (HRR 1.26, 95% CI 1.20-1.32) even when controlling for maternal and paternal traits. However, there was no association between MSDP and internalizing disorders when controlling for the mother's propensity for MSDP (depression: HRR 1.11, 95% CI 0.94-1.30; anxiety disorders: HRR 0.94, 95% CI 0.80-1.11) or comparing differentially exposed siblings (depression: HRR 1.18, 95% CI 0.75-1.89; anxiety disorders: HRR 0.87, 95% CI 0.55-1.36). CONCLUSIONS: The results suggest that familial background factors account for the association between MSDP and severe internalizing disorders not the specific exposure to MSDP.

Infections and exposure to anti-infective agents and the risk of severe mental disorders: a nationwide study.

OBJECTIVE: Severe infections are associated with increased risks of mental disorders; however, this is the first large-scale study investigating whether infections treated with anti-infective agents in the primary care setting increase the risks of schizophrenia and affective disorders. METHOD: We identified all individuals born in Denmark 1985-2002 (N = 1 015 447) and studied the association between infections treated with anti-infective agents and the subsequent risk of schizophrenia and affective disorders during 1995-2013. Cox regression analyses were adjusted for important confounders. RESULTS: Infections treated with anti-infective agents were associated with increased risks of schizophrenia by a hazard rate ratio (HRR) of 1.37 (95%-CI = 1.20-1.57) and affective disorders by a HRR of 1.64 (95%-CI = 1.48-1.82), fitting a dose-response and temporal relationship (P < 0.001). The excess risk was primarily driven by infections treated with antibiotics, whereas infections treated with antivirals, antimycotics, and antiparasitic agents were not significant after mutual adjustment. Individuals with infections requiring hospitalization had the highest risks for schizophrenia (HRR = 2.05; 95%-CI = 1.77-2.38) and affective disorders (HRR = 2.59; 95%-CI = 2.31-2.89). CONCLUSION: Infections treated with anti-infective agents and particularly infections requiring hospitalizations were associated with increased risks of schizophrenia and affective disorders, which may be mediated by effects of infections/inflammation on the brain, alterations of the microbiome, genetics, or other environmental factors.

Childhood adverse life events and parental psychopathology as risk factors for bipolar disorder.

Childhood adverse events are risk factors for later bipolar disorder. We quantified the risks for a later diagnosis of bipolar disorder after exposure to adverse life events in children with and without parental psychopathology. This register-based population cohort study included all persons born in Denmark from 1980 to 1998 (980 554 persons). Adversities before age 15 years were: familial disruption; parental somatic illness; any parental psychopathology; parental labour market exclusion; parental imprisonment; placement in out-of-home care; and parental natural and unnatural death. We calculated risk estimates of each of these eight life events as single exposure and risk estimates for exposure to multiple life events. Main outcome variable was a diagnosis of bipolar disorder after the age of 15 years, analysed with Cox proportional hazard regression. Single exposure to most of the investigated adversities were associated with increased risk for bipolar disorder, exceptions were parental somatic illness and parental natural death. By far the strongest risk factor for bipolar disorder in our study was any mental disorder in the parent (hazard ratio 3.53; 95% confidence interval 2.73-4.53) and the additional effects of life events on bipolar risk were limited. An effect of early adverse life events on bipolar risk later in life was mainly observed in children without parental psychopathology. Our findings do not exclude early-life events as possible risk factors, but challenge the concept of adversities as important independent determinants of bipolar disorder in genetically vulnerable individuals.

High loading of polygenic risk in cases with chronic schizophrenia.

Genomic risk profile scores (GRPSs) have been shown to predict case-control status of schizophrenia (SCZ), albeit with varying sensitivity and specificity. The extent to which this variability in prediction accuracy is related to differences in sampling strategies is unknown. Danish population-based registers and Neonatal Biobanks were used to identify two independent incident data sets (denoted target and replication) comprising together 1861 cases with SCZ and 1706 controls. A third data set was a German prevalent sample with diagnoses assigned to 1773 SCZ cases and 2161 controls based on clinical interviews. GRPSs were calculated based on the genome-wide association results from the largest SCZ meta-analysis yet conducted. As measures of genetic risk prediction, Nagelkerke pseudo-R(2) and variance explained on the liability scale were calculated. GRPS for SCZ showed positive correlations with the number of psychiatric admissions across all P-value thresholds in both the incident and prevalent samples. In permutation-based test, Nagelkerke pseudo-R(2) values derived from samples enriched for frequently admitted cases were found to be significantly higher than for the full data sets (Ptarget=0.017, Preplication=0.04). Oversampling of frequently admitted cases further resulted in a higher proportion of variance explained on the liability scale (improvementtarget= 50%; improvementreplication= 162%). GRPSs are significantly correlated with chronicity of SCZ. Oversampling of cases with a high number of admissions significantly increased the amount of variance in liability explained by GRPS. This suggests that at least part of the effect of common single-nucleotide polymorphisms is on the deteriorative course of illness.

A population-based study of the risk of schizophrenia and bipolar disorder associated with parent-child separation during development.

BACKGROUND: There is growing interest in the role of childhood adversities, including parental death and separation, in the etiology of psychotic disorders. However, few studies have used prospectively collected data to specifically investigate parental separation across development, or assessed the importance of duration of separation, and family characteristics. METHOD: We measured three types of separation not due to death: maternal, paternal, and from both parents, across the ages of 1-15 years among a cohort of 985 058 individuals born in Denmark 1971-1991 and followed to 2011. Associations with narrowly and broadly defined schizophrenia and bipolar disorder in the psychiatric register were assessed in terms of separation occurrence, age of separation, and number of years separated. Interactions with parental history of mental disorder were assessed. RESULTS: Each type of separation was associated with all three outcomes, adjusting for age, sex, birth period, calendar year, family history of mental disorder, urbanicity at birth and parental age. Number of years of paternal separation was positively associated with both schizophrenia and bipolar disorder. Associations between separation from both parents and schizophrenia were stronger when separation occurred at later ages, while those with bipolar disorder remained stable across development. The first occurrence of paternal separation appeared to increase risk more when it occurred earlier in childhood. Associations differed according to parental history of mental disorder, although in no situation was separation protective. CONCLUSIONS: Effects of parental separation may differ by type, developmental timing and family characteristics. These findings highlight the importance of considering such factors in studies of childhood adversity.

Parental history of psychiatric diagnoses and unipolar depression: a Danish National Register-based cohort study.

BACKGROUND: Depression is known to run in families, but the effects of parental history of other psychiatric diagnoses on depression rates are less well studied. Few studies have examined the impact of parental psychopathology on depression rates in older age groups. METHOD: We established a population-based cohort including all individuals born in Denmark after 1954 and alive on their 10th birthday (N = 29 76 264). Exposure variables were maternal and paternal history of schizophrenia, bipolar disorder, depression, anxiety or 'other' psychiatric diagnoses. Incidence rate ratios (IRRs) were estimated using Poisson regressions. RESULTS: Parental history of any psychiatric diagnosis increased incidence rates of outpatient (maternal: IRR 1.88, p < 0.0001; paternal: IRR 1.68, p < 0.0001) and inpatient (maternal: IRR 1.99, p < 0.0001; paternal: IRR 1.83, p < 0.0001) depression relative to no parental history. IRRs for parental history of non-affective disorders remained relatively stable across age groups, while IRRs for parental affective disorders (unipolar or bipolar) decreased with age from 2.29-3.96 in the youngest age group to 1.53-1.90 in the oldest group. IRR estimates for all parental diagnoses were similar among individuals aged ⩾41 years (IRR range 1.51-1.90). CONCLUSIONS: Parental history of any psychiatric diagnosis is associated with increased incidence rates of unipolar depression. In younger age groups, parental history of affective diagnoses is more strongly associated with rates of unipolar depression than non-affective diagnoses; however, this distinction disappears after age 40, suggesting that parental psychopathology in general, rather than any one disorder, confers risk for depression in middle life.

Time to subsequent live birth according to mode of delivery in the first birth.

OBJECTIVE: To estimate the rate and time to next live birth by mode of delivery. DESIGN: Hospital-based cohort. SETTING: Aarhus University Hospital (AUH), Denmark. POPULATION: All pregnant women attending AUH were invited to enroll in the Aarhus Birth Cohort (ABC) study between 1989 and 2010 (n = 91,625). METHODS: Women were followed from their first live birth until the subsequent live birth or until censoring due to study end using Cox regression models. MAIN OUTCOME MEASURES: Rate and time to subsequent live birth according to mode of delivery. RESULTS: 46,162 index live births were identified, of which 22,462 (49%) had a subsequent live birth. Women with any type of caesarean had a 6% reduction in the rate of subsequent live birth (HR 0.94, 95% CI 0.89, 0.98), which remained unchanged in the analysis by type (emergency, HR 0.95, 95% CI 0.89, 1.02; elective, HR 0.91, 95% CI 0.85, 0.98) compared with women who had a spontaneous vaginal delivery (SVD). Operative vaginal delivery was associated with an 8% reduction in subsequent live birth rates (HR 0.92, 95% CI 0.86, 0.98) and vaginal delivery complicated by shoulder dystocia with a 19% reduction compared with SVD. Median time to next birth in days was shortest in women with a first caesarean (994 days, 95% CI 973, 1026) and longest in women with a vaginal delivery complicated by shoulder dystocia (1065 days, 95% CI 994, 1191). In women with planned pregnancies, the shortest median time to second birth was in women with breech vaginal deliveries (859 days, 95% CI 737, 1089) and the longest in women with vaginal deliveries complicated by shoulder dystocia (1193 days, 95% CI 1028, 1430). CONCLUSION: The impact of mode of delivery on subsequent rate and time to next birth was minimal in this study. The greatest reduction was among women with assisted vaginal delivery complicated by shoulder dystocia. This study is strengthened by data on pregnancy planning as well as information on complications of pregnancy, delivery and neonatal morbidities, all of which may influence a woman's decision on subsequent birth.

Post-illness-onset risk of offending across the full spectrum of psychiatric disorders.

BACKGROUND: The link between psychotic disorders and violent offending is well established; knowledge about risk of post-illness-onset offending across the full spectrum of psychiatric disorders is lacking. We aimed to compare rates of any offending and violent offending committed after the onset of illness, according to diagnostic group, with population controls. METHOD: A 25% random sample of the Danish population (n = 521 340) was followed from their 15th birthday until offending occurred. Mental health status was considered as a time-varying exposure in a Poisson regression model used to examine the duration from service contact to the offence. RESULTS: Males with any psychiatric contact had an incidence rate ratio (IRR) of 2.91 [95% confidence interval (CI) 2.80-3.02] for any offending; 4.18 (95% CI 3.99-4.38) for violent offending. Associations were stronger for women (IRR 4.17, 95% CI 3.95-4.40 for any offending; 8.02, 95% CI 7.20-8.94 for violent offending). Risk was similar across diagnostic groups for any offending in males, while variation between diagnostic groups was seen for male violent and female offending, both any and violent. CONCLUSIONS: Risk of offending, particularly violent offending, was elevated across a range of mental disorders following first contact with mental health services. The extent of variation in strength of effect across diagnoses differed by gender.

Gender-age interaction in incidence rates of childhood emotional disorders.

BACKGROUND: The post-pubertal association of female gender with emotional disorder is a robust finding. However, studies exploring the association of gender and emotional disorders before puberty are few and present diverging results. The aim of this study was to present gender-specific incidence rates of emotional disorders throughout childhood. METHOD: This is a population-based cohort study of 907,806 Danish 3- to 18-year-olds. The outcome was assignment of an emotional disorder diagnosis based on in-patient and out-patient data from The Danish Psychiatric Central Register. Outcome measures were incidence rates and cumulative incidences for unipolar depressive disorder (ICD-10: F32-F33), anxiety disorders (ICD-10: F40-F42), and emotional disorders with onset specific to childhood (ICD-10: F93). RESULTS: Pre-pubertal incidence rates for depressive and anxiety disorders were higher for boys than girls. At age 12 years the pattern reversed. The cumulative incidence for any emotional disorder (F32-F33, F40-F42, F93) on the 11th birthday was 0.52% (95% CI 0.50-0.55) for boys and 0.31% (95% CI 0.29-0.33) for girls. On the 19th birthday cumulative incidence was 2.33% (95% CI 2.24-2.43) for boys and 3.77% (95% CI 3.64-3.90) for girls. The pre-pubertal male preponderance was also significant for depressive disorders (F32-F33, p = 0.00144) and anxiety disorders (F40-F42, F93, p < 0.00001) separately. CONCLUSIONS: Emotional disorders seem to display a male preponderance before the age of 12 years and a female preponderance thereafter. Studies exploring this gender-age interaction are needed. Still, the results question the general assumption that females throughout the lifespan are more at risk for emotional disorders than males.

The association between family history of mental disorders and general cognitive ability.

There is an emerging literature linking cognitive ability with a wide range of psychiatric disorders. These findings have led to the hypothesis that diminished 'cognitive reserve' is a causal risk factor for psychiatric disorders. However, it is also feasible that a family history of mental disorders may confound this relationship, by contributing to both a slight impairment in cognitive ability, and an increased risk of psychiatric disorder. On the basis of a large, population-based sample of young adult male conscripts (n=160 608), we examined whether the presence of a family history of a range of mental disorders was associated with cognitive ability, as tested by the Børge Priens Prøve. In those with no individual-level history of mental disorder, a family-level history of a mental disorder was associated with a slight reduction in cognitive ability. In general, this pattern was found regardless of the nature of the psychiatric disorder in the family. Our study suggests that shared familial factors may underpin both cognitive ability and the risk of a wide range of psychiatric disorders. Convergent evidence from epidemiology and genetics suggests that shared genetic factors underpin an unexpectedly diverse range of psychiatric disorders. On the basis of the findings of the current study, we speculate that these same shared genetic factors also contribute to general cognitive ability.

Genome-wide study of association and interaction with maternal cytomegalovirus infection suggests new schizophrenia loci.

Genetic and environmental components as well as their interaction contribute to the risk of schizophrenia, making it highly relevant to include environmental factors in genetic studies of schizophrenia. This study comprises genome-wide association (GWA) and follow-up analyses of all individuals born in Denmark since 1981 and diagnosed with schizophrenia as well as controls from the same birth cohort. Furthermore, we present the first genome-wide interaction survey of single nucleotide polymorphisms (SNPs) and maternal cytomegalovirus (CMV) infection. The GWA analysis included 888 cases and 882 controls, and the follow-up investigation of the top GWA results was performed in independent Danish (1396 cases and 1803 controls) and German-Dutch (1169 cases, 3714 controls) samples. The SNPs most strongly associated in the single-marker analysis of the combined Danish samples were rs4757144 in ARNTL (P=3.78 × 10(-6)) and rs8057927 in CDH13 (P=1.39 × 10(-5)). Both genes have previously been linked to schizophrenia or other psychiatric disorders. The strongest associated SNP in the combined analysis, including Danish and German-Dutch samples, was rs12922317 in RUNDC2A (P=9.04 × 10(-7)). A region-based analysis summarizing independent signals in segments of 100 kb identified a new region-based genome-wide significant locus overlapping the gene ZEB1 (P=7.0 × 10(-7)). This signal was replicated in the follow-up analysis (P=2.3 × 10(-2)). Significant interaction with maternal CMV infection was found for rs7902091 (P(SNP × CMV)=7.3 × 10(-7)) in CTNNA3, a gene not previously implicated in schizophrenia, stressing the importance of including environmental factors in genetic studies.