Study objective: To describe gender specific suicide rates associated with partner’s psychiatric disorder, loss of a spouse, or child by suicide or other causes, being a parent, and marital status. ...Design: Nested case-control study. Information on causes of death, psychiatric admission, marital status, children, and socioeconomic factors was obtained from routine registers. Setting: Denmark. Participants: 9011 people aged 25–60 years who committed suicide; 180 220 age-gender matched controls; 111 172 marital partners; 174 672 children. Main results: The suicide risk in women whose partner had been first admitted with a psychiatric disorder after 31 December two years earlier was 6.9 (95% CI 3.6 to 13.0), whereas their male counterpart experienced a risk of 3.9 (2.7 to 5.6); p value gender difference = 0.39. Men who had lost their partner by suicide or other causes of death experienced a suicide risk of 46.2 (18.3 to 116.4) and 10.1 (6.5 to 15.8), respectively; the analogous risk among women were about one third: 15.8 (6.6 to 37.4) and 3.3 (1.5 to 7.2), respectively. Child bereavement by suicide or other causes imposed an approximate twofold risk increase in their parents, whereas being a parent was protective in women. Except for widows (1.6, 1.2 to 2.0) and widowers (3.0, 2.3 to 3.9) the suicide risk associated with being separated (2.0, 1.8 to 2.3), divorced (1.8, 1.7 to 2.0), never married (1.4, 1.3 to 1.6), cohabitant (1.2, 1.1 to 1.3) was virtually the same in the two sexes. Conclusions: The suicide risk is associated with partner psychiatric illness. Conjugal bereavement is particularly indicative of suicide in men, and spousal suicide is particularly indicative of suicide. Child bereavement is associated with parental suicide, while being a parent is protective against suicide in women.
Background and purpose
Amyotrophic lateral sclerosis (ALS) risk increases with age, and a linear log‐incidence and log‐age relationship is interpreted to suggest that five to six factors are involved ...in disease onset. The factors remain unidentified, except that fewer steps are predicted for those carrying a known ALS‐causing mutation.
Methods
Men with a psychiatric disorder or cardiovascular disease (CVD) diagnosis have an increased relative risk of ALS. Using the Danish population registries and ALS diagnosis years 1980 to 2017, we tested whether these factors would decrease the predicted steps to disease.
Results
Consistent with previous reports, we find a linear log‐incidence and log‐age ALS‐onset relationship (n = 4385, regression coefficient b = 4.6, 95% confidence interval CI: 4.3–4.9, R2 = 0.99). This did not differ when considering ALS cases with a prior psychiatric diagnosis (n = 391, b = 4.6, 95% CI: 4.0–5.1) Surprisingly, it was higher (+1.5 steps, P = 2.3 × 10−5) for those with a prior CVD diagnosis (n = 901, b = 6.1, 95% CI: 5.4–6.8). To control for competing risk of death, a test to investigate if this effect was maintained in those with CVD in the population demonstrated an increased baseline risk and fewer steps to disease (b = 1.8, 95% CI: 1.2–2.3, P = 4.6 × 10−21), which consistent with a positive association of CVD and ALS. Assessing sex differences, our data and meta‐analyses (n = 22 495) support half a step fewer for men (−0.4, 95% CI: ±0.24, P = 0.00031) without support for contributing differences explained by menopause.
Conclusions
Any factor associated with ALS disease onset may be relevant for understanding disease pathogenesis and/or counselling. Modelling disease incidence with age demonstrates some insight into relevant risk factors; however, the outcome can differ if competing risks are considered.
Amyotrophic lateral sclerosis (ALS) risk increases with age. A log‐incidence versus log‐age curve suggests that five to six factors are involved in disease onset. The factors remain unidentified, except that fewer steps are predicted for those with an ALS‐causing mutation. Consistent with previous research, we find a linear ALS‐onset relationship in the Danish population. This did not differ when considering ALS cases with a prior psychiatric diagnosis. Assessment of a prior cardiovascular disease (CVD) diagnosis in ALS in a CVD population and a meta‐analysis of males versus females demonstrated fewer steps to disease. The underlying contributing mechanisms for CVD/sex and ALS are unknown and probably complex.
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.
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.
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.
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.
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.
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.
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).
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.
The postpartum period is well-known risk period for the first onset of autoimmune thyroid disorders (AITDs) as well as first onset of psychiatric disorders. These two disorders are some of the most ...prevalent medical conditions postpartum, often misdiagnosed and disabling if left untreated. Our study was designed to explore the possible bidirectional association between AITDs and psychiatric disorders during the postpartum period.
A population-based cohort study through linkage of Danish national registers, which comprised 312 779 women who gave birth to their first child during 1997-2010. We conducted Poisson regression analysis to estimate the incidence rate ratio (IRR) of psychiatric disorders among women with first-onset AITDs, the IRR of AITDs among women with first-onset psychiatric disorders as well as the overlap between these disorders using a comorbidity index.
Women with first-onset AITDs postpartum were more likely to have first-onset psychiatric disorders than women who did not have postpartum AITDs (IRR = 1.88, 95% confidence interval (CI): 1.25-2.81). Women with first-onset postpartum psychiatric disorders had a higher risk of AITDs than women with no psychiatric disorders (IRR = 2.16, 95% CI: 1.45-3.20). The comorbidity index 2 years after delivery was 2.26 (95% CI: 1.61-2.90), indicating a comorbidity between first-onset AITDs and psychiatric disorders.
First-onset AITDs and psychiatric disorders co-occur in the postpartum period, which has relevance to further studies on the etiologies of these disorders and why childbirth in particular triggers the onset.
Abstract
STUDY QUESTION
Are women with a history of first-onset postpartum psychiatric disorders after their first liveborn delivery less likely to have a subsequent live birth?
SUMMARY ANSWER
Women ...with incident postpartum psychiatric disorders are less likely to go on to have further children.
WHAT IS KNOWN ALREADY
Women are particularly vulnerable to psychiatric disorders in the postpartum period. The potential effects of postpartum psychiatric disorders on the mother’s future chances of live birth are so far under-researched.
STUDY DESIGN, SIZE, DURATION
A population-based cohort study consisted of 414 571 women who had their first live birth during 1997–2015. We followed the women for a maximum of 19.5 years from the date of the first liveborn delivery until the next conception leading to a live birth, emigration, death, their 45th birthday or 30 June 2016, whichever occurred first.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Postpartum psychiatric disorders were defined as filling a prescription for psychotropic medications or hospital contact for psychiatric disorders for the first time within 6 months postpartum. The outcome of interest was time to the next conception leading to live birth after the first liveborn delivery. Records on the death of a child were obtained through the Danish Register of Causes of Death. Cox regression was used to estimate the hazard ratios (HRs), stratified by the survival status of the first child.
MAIN RESULTS AND THE ROLE OF CHANCE
Altogether, 4327 (1.0%) women experienced postpartum psychiatric disorders after their first liveborn delivery. The probability of having a subsequent live birth was 69.1% (95% CI: 67.4–70.7%) among women with, and 82.3% (95% CI: 82.1–82.4%) among those without, postpartum psychiatric disorders. Women with postpartum psychiatric disorders had a 33% reduction in the rate of having second live birth (HR = 0.67, 95% CI: 0.64–0.69), compared to women without postpartum psychiatric disorders. The association disappeared if the first child died (HR = 1.01, 95% CI: 0.85–1.20). If postpartum psychiatric disorders required hospitalisations, this was associated with a more pronounced reduction in live birth rate, irrespective of the survival status of the first child (HR = 0.54, 95% CI: 0.47–0.61 if the first child survived, and HR = 0.49, 95% CI: 0.23–1.04 if the first child died).
LIMITATIONS, REASONS FOR CAUTION
The use of population-based registers allows for the inclusion of a representative cohort with almost complete follow-up. The large sample size enables us to perform detailed analyses, accounting for the survival status of the child. However, we did not have accurate information on stillbirths and miscarriages, and only pregnancies that led to live birth were included.
WIDE IMPLICATIONS OF THE FINDINGS
Our study is the first study to investigate subsequent live birth after postpartum psychiatric disorders in a large representative population. The current study indicates that postpartum psychiatric disorders have a significant impact on subsequent live birth, as women experiencing these disorders have a decreased likelihood of having more children. However, the variations in subsequent live birth rate are influenced by both the severity of the disorders and the survival status of the first-born child, indicating that both personal choices and decreased fertility may have a role in the reduced subsequent live birth rate among women with postpartum psychiatric disorders.
STUDY FUNDING/COMPETING INTEREST(S)
This work was supported by the Danish Council for Independent Research (DFF-5053-00156B), the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 837180, AUFF NOVA (AUFF-E 2016-9-25), iPSYCH, the Lundbeck Foundation Initiative for Integrative Psychiatric Research (R155-2014-1724), Niels Bohr Professorship Grant from the Danish National Research Foundation and the Stanley Medical Research Institute, the National Institute of Mental Health (NIMH) (R01MH104468) and Fabrikant Vilhelm Pedersen og Hustrus Legat. The authors do not declare any conflicts of interest.
TRIAL REGISTRATION NUMBER
N/A.
Objective
Evidence point to intergenerational effects of trauma in refugee populations. This study estimates the risk of psychiatric diagnoses in children of severely traumatized refugees. The unique ...clinical sample consisted of refugee parents treated for torture trauma and war trauma, and outcomes were investigated using population‐level data.
Method
A nationwide register study, following all children residing in Denmark. The exposure was parental torture trauma and war trauma, and outcomes were any psychiatric disorder, mood, neurotic, behavioural and emotional disorders and disorders of psychological development. Children’s hazard of being diagnosed was estimated using Cox proportional hazards regression. Study participants were followed from the date of birth or immigration to their 18th birthday.
Results
The cohort included 3 346 993 children of which 19 294 were identified as offspring to traumatized refugees. During the study period, 205 610 children were diagnosed with a psychiatric disorder. Children with parents from the Middle East and Northern Africa had a hazard ratio of 0.78 (95% CI: 0.72, 0.84) for those treated for parental trauma and 0.79 (95% CI: 0.76, 0.81) for those not treated compared with children of non‐traumatized Danish‐born parents. For children of parents from former Yugoslavia, the corresponding estimates were 0.69 (95% CI: 0.58, 0.81) and 0.69 (95% CI: 0.65, 0.73).
Conclusion
The results suggest that children of parents with and without registered torture trauma and war trauma have a lower risk of being diagnosed with a psychiatric disorder compared to children of Danish‐born parents. These findings contradict research done on the transmission of trauma but supports evidence suggesting mental health services underutilization by refugee and ethnic minority populations.
Study objective: To describe the association between labour market status and death by suicide with focus on admission with a psychiatric disorder. Design: Nested case-control study. Data from ...routine registers. Setting: Entire Danish population. Participants: 9011 people aged 25–60 years who committed suicide during 1982–1997 and 180 220 matched controls. Main results: In the general population, not being fully employed is associated with a twofold to threefold increased relative risk of death by suicide, compared with being fully employed. In contrast, fully employed people who have been first admitted to a psychiatric hospital within the past year are at increased suicide risk. Patients who are unemployed, social benefits recipients, disability pensioners, or otherwise marginalised on the labour market have a suicide risk of 0.60 (95% CI: 0.46 to 0.78), 0.41 (0.23 to 0.74), 0.70 (0.45 to 1.08), and 0.86 (0.53 to 1.41), respectively. Although a similar risk decrease is found in women, men, people younger than 30 years, people older than 45 years, and in people who become unemployed, the reversed effect attenuates with time since admission, and little association is seen when a marginal structural model is applied. Conclusions: Although the results show an increased suicide mortality associated with unemployment and labour market marginalisation in the general population, the results suggest little or an inverse association between unemployment and suicide in people with psychiatric illness. The associations seen suggest the need to consider healthy worker selection effects when studying the causal pathway from unemployment and psychiatric illness to suicide.
Background
There is increasing interest in the possible link between maternal hypothyroidism in the perinatal period and childhood asthma risk. We explored this in this study while accounting for the ...timing of hypothyroidism diagnosis. Further, we evaluated whether the risk was moderated by thyroid hormone treatment during pregnancy.
Methods
We conducted a population‐based cohort study using Danish national registers. All live‐born singletons in Denmark from 1998 to 2007 were identified. Maternal hypothyroidism and asthma in the children were defined by data from the Patient Register and Prescription Registry. We estimated incidence rate ratios (IRRs) of asthma among children born to hypothyroid mothers versus children born to mothers with no recorded thyroid dysfunction using Poisson regression models.
Results
Of 595 669 children, 3524 children were born to mothers with hypothyroidism diagnosed before delivery and 4664 diagnosed after delivery. Overall, 48 990 children received treatment for asthma. The IRRs of asthma was 1.16 (95% confidence interval (CI): 1.03‐1.30) and 1.12 (95% CI: 1.02‐1.24) for children born to mothers with hypothyroidism diagnosed before and after delivery, compared to children born to mothers with no thyroid dysfunction. The highest risk was observed among children born to mothers with hypothyroidism diagnosed before delivery who did not receive thyroid hormone treatment during pregnancy (IRR=1.37, 95% CI: 1.04‐1.80).
Conclusion
Our findings suggest that maternal hypothyroidism, especially when it is untreated, increases childhood asthma risk. Early detection and appropriate treatment of hypothyroidism in pregnant women may be an area for possible prevention of childhood asthma.
Objectives: To examine the risk of affective and stress related disorders among men and women employed in human service professions. Methods: Population based case-control study using data from ...national registers. Cases (n = 28 971) were identified in the Danish Psychiatric Central Research Register among all hospitalised patients and outpatients aged 18–65 who received a first time ever diagnosis of affective (ICD-10, F30–39) or stress related (ICD-10, F40–48) disorder from 1 January 1995 to 31 December 1998. Each case was assigned five never admitted referents (n = 144 855) of the same gender and age, randomly drawn from a 5% sample of the Danish population obtained from Statistics Denmark’s Integrated Database for Labour Market Research. Occupation held the year before matching was classified according to the Danish version of the International Classification of Occupation. Health care, education, social work, and customer services were defined as human service professions and constituted 21% of all employed in the study. Adjusted risks (hazard ratios) relative to all other occupations were calculated for 24 human service occupations. Results: The relative risk of depression in human service professions was 1.35 (95% CI 1.24 to 1.47) for women and 1.49 (95% CI 1.29 to 1.73) for men. The risk of stress was 1.18 (95% CI 1.11 to 1.26) for women and 1.49 (95% CI 1.32 to 1.67) for men. Specific professions contributed differentially to the magnitude of risk, with education and social services displaying the highest risks. No increase in risks was found in customer service occupations. Gender was a significant modifying factor with the highest risk levels in men. Conclusions: There was a consistent association between employment in human service occupations and the risk of affective and stress related disorders. Risks were highest for men working in these typically female professions. More work is needed to distinguish work hazards from effects attributable to selection mechanisms and personality characteristics.
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