Sussie Antonsen

National Cohort Study of Suicidality and Violent Criminality among Danish Immigrants

Background Immigrant populations in western societies have grown in their size and diversity yet evidence is incomplete for their risks of suicidality and criminal violence. We examined these correlated harmful behaviours in a national cohort. Aims (i) Compare absolute risk between first and second generation immigrants, foreign-born adoptees and native Danes by plotting cumulative incidence curves to onset of early middle age; (ii) estimate sex-specific relative risks for these immigrant type subgroups vs. native Danes; (iii) examine effect modification by higher vs. lower socio-economic status. Methods In a cohort of over two million persons, attempted suicides and violent crimes were investigated using data from multiple interlinked registers. We plotted sex-specific cumulative incidence curves and estimated incidence rate ratios. Results In the whole study cohort, 1414 people died by suicide, 46,943 attempted suicide, and 51,344 were convicted of committing a violent crime. Among all immigrant subgroups combined, compared with native Danes, relative risk of attempted suicide was greater in female immigrants (incidence rate ratio, 1.59; 95% confidence interval: CI 1.54-1.64) than in male immigrants (1.26; CI 1.20-1.32), and vice versa for relative risk of violent offending in male immigrants (2.36; CI 2.31-2.42) than in female immigrants (1.74; CI 1.62-1.87). Risk for both adverse outcomes was significantly elevated in virtually every gender-specific immigrant type subgroup examined. Violent crime risk was markedly raised in first generation immigrant males and in the Danish born male children of two immigrant parents. However, male immigrants of lower social status had lower risk of attempted suicide than their native Danish peers. Conclusion Young immigrants of both first and second generation status face serious challenges and vulnerabilities that western societies need to urgently address. Relative risk patterns for these adverse outcomes vary greatly between the genders and also by socioeconomic status. This high degree of heterogeneity points to the existence of modifiable factors that are amenable to positive change and a potential for effective intervention.

Parental psychiatric disease and risks of attempted suicide and violent criminal offending in offspring: a population-based cohort study

ImportancenSelf-directed and interpersonal violence share some common risk factors such as a parental history of mental illness. However, relationships between the full spectrum of parental psychiatric disease and these 2 related outcomes are unclear.nnnObjectivenTo examine associations between the full spectrum of parental psychiatric disease and risks of attempted suicide and violent offending among offspring.nnnDesign, Setting, and ParticipantsnPopulation-based cohort study of all persons born in Denmark 1967 through 1997, followed up from their 15th birthday until occurrence of adverse outcome or December 31, 2012, whichever came first.nnnExposuresnArray of parental psychiatric disorders and parental suicide attempt, delineated from records of secondary care treatments.nnnMain Outcomes and MeasuresnUsing survival analyses techniques, incidence rate ratios were estimated for offspring suicide attempt and violent offending.nnnResultsnWe examined 1u202f743u202f525 cohort members (48.7% female; total follow-up, 27.2 million person-years). Risks for offspring suicide attempt and violent offending were elevated across virtually the full spectrum of parental psychiatric disease. Incidence rate ratios were the most elevated for parental diagnoses of antisocial personality disorder (suicide attempt, 3.96; 95% CI, 3.72-4.21; violent offending, 3.62; 95% CI, 3.41-3.84) and cannabis misuse (suicide attempt, 3.57; 95% CI, 3.25-3.92; violent offending, 4.05; 95% CI, 3.72-4.39), and for parental suicide attempt (suicide attempt, 3.42; 95% CI, 3.29-3.55; violent offending, 3.31; 95% CI, 3.19-3.44). Parental mood disorders (and bipolar disorder in particular) conferred more modest risk increases. A history of mental illness or suicide attempt in both parents was associated with double the risks compared with having just 1 affected parent. Associations between parental psychiatric disease and offspring violent offending were stronger for female than for male offspring, whereas little sex difference in risk was found for offspring suicide attempt.nnnConclusions and RelevancenThe similarities in risk patterns observed between the 2 outcomes may evidence a shared etiology. Early interventions to tackle parental mental disorders may be beneficial to both parents and children.

Premature Mortality Among Patients Recently Discharged From Their First Inpatient Psychiatric Treatment

Importance Nationwide cohorts provide sufficient statistical power for examining premature, cause-specific mortality in patients recently discharged from inpatient psychiatric services. Objective To investigate premature mortality in a nationwide cohort of patients recently discharged from inpatient psychiatric treatment at ages 15 to 44 years. Design, Setting, and Participants This single-cohort design included all persons born in Denmark (Nu2009=u20091u2009683u2009385) between January 1, 1967, and December 31, 1996. Exactly 48u2009599 of these Danish residents were discharged from an inpatient psychiatric unit or ward on or after their 15th birthday, which took place during this study’s observation period from January 1, 1982, through December 31, 2011. This group of patients was followed up beginning on their 15th birthday until their death, emigration, or December 31, 2011, whichever came first. Individuals discharged from inpatient psychiatric care at least once before their 15th birthday (nu2009=u20095882) were excluded from the study. All data were obtained from the Danish Civil Registration System, Psychiatric Central Research Register, and Register of Causes of Death. Data analysis took place between February 1, 2016, and December 10, 2016. Main Outcomes and Measures Incidence rates and incidence rate ratios (IRRs) for all-cause mortality and for an array of unnatural and natural causes of death among patients recently discharged from an inpatient psychiatric unit vs persons not admitted to a psychiatric facility. Primary analysis considered risk within the year of first discharge. Results Of the 48u2009599 discharged patients who were included in the study, 25 006 (51.4%) were female, 35 660 (73.4%) were aged 15 to 29 years, and 33 995 (70.0%) had a length of stay of 30 days or less. Compared with persons not admitted, patients discharged had an elevated risk for all-cause mortality within 1 year (IRR, 16.2; 95% CI, 14.5-18.0). The relative risk for unnatural death (IRR, 25.0; 95% CI, 22.0-28.4) was much higher than for natural death (IRR, 8.6; 95% CI, 7.0-10.7). The highest IRR found was for suicide at 66.9 (95% CI, 56.4-79.4), followed by alcohol-related death at 42.0 (95% CI, 26.6-66.1). Among the psychiatric diagnostic categories assessed, psychoactive substance abuse conferred the highest risk for all-cause mortality (IRR, 24.8; 95% CI, 21.0-29.4). Across the array of cause-specific outcomes examined, risk of premature death during the first year after discharge was markedly higher than the risk of death beyond the first year of discharge. Conclusions and Relevance Clinicians may help protect patients after discharge by serving as a liaison between primary and secondary health services to ensure they are receiving holistic care. Early intervention programs for drug and alcohol misuse could substantially decrease the greatly elevated mortality risk among these patients.

Self-harm and violent criminality among young people who experienced trauma-related hospital admission during childhood: a Danish national cohort study

Summary Background Development of a better understanding of subsequent pathways for individuals who experienced trauma during childhood might usefully inform clinicians and public health professionals regarding the causes of self-harm and interpersonal violence. We aimed to examine these risks during late adolescence and early adulthood among people admitted to hospital following injuries or poisonings during their childhood. Methods This national cohort study included Danish people born between Jan 1, 1977, and Dec 31, 1997, and was linked to the National Patient Register and Psychiatric Central Research Register to identify all people exposed to hospital admissions for injuries or poisonings due to self-harm, interpersonal violence, or accidents before their 15th birthday. Linkage to these two registers and to the National Crime Register enabled ascertainment of self-harm and violent offending, respectively, as adverse outcomes at ages 15–35 years. Sex-specific incidence rate ratios (IRRs; relative risks) and cumulative incidence percentage values (absolute risks) were estimated. The confounding influence of parental socioeconomic status was also explored. Findings 1u2008087u2008672 Danish people were included in this study. The prevalence of any trauma-related hospital admission was 10% (105u2008753 per 1u2008087u2008672; males: 64u2008454 [11%]; females: 44u2008299 [8%]) and for both sexes, accident was by far the most prevalent of the categories assessed (males: 59u2008011 [11%]; females: 40u2008756 [8%]). Similar patterns of increased risk for self-harm and violent criminality were observed in both sexes, although the IRRs were consistently and significantly larger in women (self-harm: IRR 1·94 [95% CI 1·85–2·02]; violent criminality: 2·16 [1·97–2·36]) than in men (self-harm: 1·61 [1·53–1·69]; violent criminality: 1·58 [1·53–1·63]). Confounding by parental socioeconomic status explained little of the increased risks observed. For young adult men, the highest absolute risk observed was for violent offending among individuals admitted to hospital for interpersonal violence injury during childhood (cumulative incidence 25·0% [95% CI 21·2–28·9]). For young adult women, absolute risk was highest for repeat self-harm among those admitted to hospital following self-harm during childhood (cumulative incidence 21·4% [95% CI 19·8–23·1]). More frequent trauma-related hospital admissions in childhood, and being admitted multiple times for more than one reason, conferred substantial risk increases among young people, with especially steep gradients of this nature observed among women. Interpretation Trauma-related hospital admission early in life could be a useful marker for childhood distress that subsequently predicts internalised and externalised destructive behaviours among youths and young adults and might provide a timely opportunity for initiating family-oriented interventions. Funding European Research Council.

Younger or older parental age and risk of suicidality, premature death, psychiatric illness, and criminality in offspring

Background Younger or older parental age has been linked with a range of adverse offspring endpoints. We investigated associations between parental age and nine adverse offspring outcomes in three correlated domains: (i) Premature death: suicide, unnatural death, natural death; (ii) Psychiatric morbidity: any mental illness, suicide attempt, substance misuse; (iii) Criminality: violent offending, imprisonment, driving whilst intoxicated. Methods Persons born in Denmark 1966–1996 were followed from their 15th until 40th birthday or December 2011 (N=1,793,681). Incidence rate ratios were estimated. Results Offspring of teenage mothers had the greatest risks for all nine adverse outcomes, especially for imprisonment, violent offending, substance misuse, and attempted suicide. Teenage fatherhood was also associated with elevated risks for offspring adverse psychiatric and criminality outcomes, but not premature mortality (at ages 15–39 years). For the psychiatric and criminality outcomes there was a U-shape trend linked with paternal age, but risks for premature mortality tended to increase with rising paternal age. On the contrary, maternal age 30 years and over was not linked with raised risks for any of the outcomes examined. Limitations Parental links are based on legal and not biological relationships. Conclusions The substantially elevated risks linked with teenage motherhood for a variety of poor offspring outcomes is a concern for clinicians and policymakers. The associations observed across such a wide array of adverse outcomes also suggest that multiple causal mechanisms may be implicated.

National cohort study of absolute risk and age-specific incidence of multiple adverse outcomes between adolescence and early middle age

BackgroundPsychiatric illness, substance misuse, suicidality, criminality and premature death represent major public health challenges that afflict a sizeable proportion of young people. However, studies of multiple adverse outcomes in the same cohort at risk are rare. In a national Danish cohort we estimated sex- and age-specific incidence rates and absolute risks of these outcomes between adolescence and early middle age.MethodsUsing interlinked registers, persons born in Denmark 1966–1996 were followed from their 15th until 40th birthday or December 2011 (Nu2009=u20092,070,904). We estimated sex- and age-specific incidence rates of nine adverse outcomes, in three main categories: Premature mortality (all-causes, suicide, accident); Psychiatric morbidity (any mental illness diagnosis, suicide attempt, alcohol or drug misuse disorder); Criminality (violent offending, receiving custodial sentence, driving under influence of alcohol or drugs). Cumulative incidences were also calculated using competing risk survival analyses.ResultsFor cohort members alive on their 15th birthday, the absolute risks of dying by age 40 were 1.99xa0% for males [95xa0% confidence interval (CI) 1.95–2.03xa0%] and 0.85xa0% for females (95xa0% CI 0.83–0.88xa0%). The risks of substance misuse and criminality were also much higher for males, especially younger males, than for females. Specifically, the risk of a first conviction for a violent offence was highest amongst males aged below 20. Females, however, were more likely than males to have a hospital-treated psychiatric disorder. By age 40, 13.25xa0% of females (95xa0% CI 13.16–13.33xa0%) and 9.98xa0% of males (95xa0% CI 9.91–10.06xa0%) had been treated. Women aged below 25 were also more likely than men to first attempt suicide, but this pattern was reversed beyond this age. The greatest gender differentials in incidence rates were in criminality outcomes.ConclusionsThis is the first comprehensive assessment of the incidence rates and absolute risks of these multiple adverse outcomes. Approximately 1 in 50 males and 1 in 120 females who are alive on their 15th birthday will die by age 40. By examining the same cohort at risk, we compared risks for multiple outcomes without differential inter-cohort biases. These epidemiological profiles will inform further research into the pathways leading to these adverse events and future preventive strategies.

Family income inequalities and trajectories through childhood and self-harm and violence in young adults: a population-based, nested case-control study

BACKGROUNDnChildhood poverty is associated with elevated later risks for self-directed and externalised violence, but how risks are modified by parental socioeconomic mobility remains unclear. We investigated parental income trajectories during childhood and subsequent risks of self-harm and violent criminality in young adulthood.nnnMETHODSnUsing Danish national registers, we delineated a nested case-control study of Danish citizens born from Jan 1, 1982, to Dec 31, 2000, with first hospital-treated self-harm episodes and first violent crime convictions at ages 15-33 years. Each case was matched on age and gender to 25 randomly selected controls. Parental income was assessed in birth-year and at ages 5 years, 10 years, and 15 years. We considered parental age, the childs number of siblings, parental mental health, and parental education to be covariates. We estimated incidence rate ratios (IRRs) by conditional logistic regression inherently adjusted for age, gender, and calendar year; we then made additional adjustments for the covariates considered.nnnFINDINGSnWe identified 21u2008267 first episodes of hospital-treated self-harm, to which we matched 531u2008675 controls, and 23u2008724 first violent crime convictions, to which we matched 593u2008100 controls. We observed inverse relationships between parental income and risks for the two outcomes for each of the ages parental income was measured. The longer a child lived in poorer circumstances, the higher their subsequent risks for self-harm and violent criminality, and vice versa for time spent living in affluent conditions. Associations were stronger for violent criminality than for self-harm. Compared with individuals who were born and remained in the most affluent families, all other income trajectories were associated with elevated risks for both outcomes. Those who remained in the least affluent quintile showed the highest risks for self-harm (IRR 7·2, 95% CI 6·6-7·9; 1174 [6%] cases) and for violent criminality (IRR 13·0; 95% CI 11·9-14·1; 1640 [7%] cases). The risk patterns were attenuated, but essentially persisted, after covariate adjustment. For any parental income level at birth, being upwardly mobile was associated with lower risk compared with downward mobility.nnnINTERPRETATIONnParental income represents a multitude of unmeasured familial sociodemographic indices. Tackling the causes of inequality and associated psychosocial and sociocultural challenges to enable upwards socioeconomic mobility could potentially reduce risks for self-directed and externalised violence.nnnFUNDINGnEuropean Research Council.

Attempted suicide and violent criminality among Danish second-generation immigrants according to parental place of origin.

Background: Immigrant populations in Western European countries have grown in their size and diversity, but little is known about risks of self-directed and externalised violence among second-generation immigrants. Aims: To compare risks for attempted suicides and violent offending among second-generation immigrants to Denmark according to parental region of origin versus the native Danish population. Methods: Data from interlinked national Danish registers were used (Nu2009=u20091,973,614). Parental origin outside Denmark was categorised thus: Asia, Africa, Middle East, Greenland, other Scandinavian countries, elsewhere in Europe and all other regions. We estimated gender-specific cumulative incidence and incidence rate ratios (IRRs) versus native Danes. Results: In virtually all subgroups of second-generation immigrants, risk was elevated for the two adverse outcomes in both genders. Females generally had greater elevations in attempted suicide risk, and males had greater elevations in violent offending risk. For attempted suicide, especially large IRRs were observed for males and females whose parents emigrated from Greenland; for violent offending, risks were particularly raised for males and females of Middle Eastern, Greenlandic and African origin. Adjustment for socioeconomic status partially explained these associations. Conclusion: Western European nations should develop preventive programmes tailored towards specific second-generation immigrant populations, with integrated approaches jointly tackling suicidality and violence.

Suicide Methods and Specific Types of Accidental Death and Fatal Poisoning Among Discharged Psychiatric Patients: A National Cohort Study

OBJECTIVEnPersons discharged from inpatient psychiatric units are at greatly elevated risk of dying unnaturally. We conducted a comprehensive examination of specific causes of unnatural death post-discharge in a national register-based cohort.nnnMETHODnA cohort of 1,683,645 Danish residents born 1967-1996 was followed from their 15th birthday until death, emigration, or December 31, 2011, whichever came first. Survival analysis techniques were used to estimate incidence rate ratios (IRRs) comparing risk for persons with and without psychiatric admission history in relation to (a) suicide method, (b) accidental death type, (c) fatal poisoning type, and (d) homicide.nnnRESULTSnMore than half (52.5%, n = 711) of all unnatural deaths post-discharge were fatal poisonings, compared with less than a fifth (17.0%, n = 1,012) among persons in the general population not admitted. Just 6.8% (n = 92) of all unnatural deaths post-discharge were due to transport accidents-the most common unnatural death type in the general population (53.4%, n = 3,184). Suicide risk was 32 times higher among discharged patients (IRR 32.3; 95% CI, 29.2-35.8) and was even higher during the first year post-discharge (IRR 70.4; 95% CI, 59.7-83.0). Among the suicide methods examined, relative risk values were significantly larger for intentional self-poisoning (IRR 40.8; 95% CI, 33.9-49.1) than for violent suicide methods (IRR 29.4; 95% CI, 26.1-33.2). The greatest relative risk observed was for fatal poisoning (irrespective of intent) by psychotropic medication (IRR 93.7; 95% CI, 62.5-140.5). The highest post-discharge mortality rate was for accidental self-poisoning among persons diagnosed with a psychoactive substance abuse disorder: 290.1 per 100,000 person-years.nnnCONCLUSIONSnCloser liaison between inpatient services and community care, more effective early treatment for comorbid substance abuse, enhanced psychosocial assessment following self-harm, and tighter medication surveillance could decrease risk of unnatural death post-discharge.

EXPOSURE TO NITROGEN DIOXIDE DURING CHILDHOOD IS ASSOCIATED WITH INCREASED RISK OF SCHIZOPHRENIA

Abstract Background Urban-rural differences in schizophrenia incidence have been reported from numerous published studies. Though as yet unknown, the underlying causes responsible for these differences have been postulated to include urban-rural differences in pollution, diet, infections, stress, or selective migration. Exposure to the air pollutant nitrogen dioxide (NO2) has been linked with increased rates of mortality, lung cancer, and psychotropic medication prescribing. However, no study to date has examined whether NO2 exposure during early childhood is associated with schizophrenia risk. Methods Utilizing individual-level information in the rich Danish population-based registers enriched with longitudinal information on residential exposure to air pollution, we investigated the putative link between NO2 exposure during childhood and schizophrenia risk. For each cohort member, exposure to NO2 was estimated longitudinally from birth to 10th birthday, expressed as mean of daily exposures at residence across the first 10 years of life. Incidence rate ratios per 10μg/m3 increase in mean NO2 exposure were estimated using survival analysis techniques. Air pollutant exposures were modelled using the UBM model in 1*1km grids covering Denmark from 1979 onwards. Results We observed a dose response relationship between childhood NO2 exposure and elevated risk for developing schizophrenia. Risk increased 1.36 fold (95%CI: 1.31–1.41) per 10μg/m3 increase in mean NO2 exposure during childhood. This association remained materially unaltered when adjusted for potential confounders such as family socioeconomic position and history of severe mental disorders. In absolute risk terms, at age 35 a person exposed to more than 25μg/m3 mean NO2 faced a 1.4% risk of schizophrenia whereas persons exposed to less than 10μg/m3 per day faced a 0.8% risk. Discussion This is the first population-based study demonstrating that exposure to NO2 during childhood is linked with elevated schizophrenia risk. The potential mechanism of NO2 on the risk of schizophrenia remains to be identified, however, if causality is proven this finding offers great potential for prevention of some cases of schizophrenia.