General medical conditions and mortality in women with postpartum psychiatric disorders.

BACKGROUND: Psychiatric patients have an increased risk of general medical conditions and mortality, but no study has systematically explored these outcomes among women with mental disorders following childbirth (postpartum psychiatric disorders: PPD). Therefore, we aimed to investigate the risk of subsequent general medical conditions and mortality in women with a broad spectrum of PPD. METHODS: This register-based cohort study followed all Danish women born after January 1, 1960, until January 1, 2016. The exposure of interest was (i) mild-moderate PPD: first-ever prescription of psychotropic medication (ATC codes: N03-N07) and (ii) severe PPD: first-ever in- or out-patient contact to a psychiatric facility, both within six months postpartum. Outcomes of interest were (i) hospital-registered chronic medical conditions and (ii) mortality from natural and unnatural causes. We included 1 841 949 women representing 22 615 310 person-years at risk. RESULTS: Among 15 852 women with mild-moderate PPD and 4266 women with severe PPD, we found a higher risk of any subsequent general medical condition (mild-moderate PPD: IRR 1.25; 95% CI 1.20-1.31 and severe PPD: IRR 1.35; 95% CI: 1.24-1.48) when compared to the female background population. Mortality from both natural and unnatural causes was higher in both groups: Mild-moderate PPD: natural causes MRR 1.37; 95% CI: 1.17-1.61; unnatural causes MRR 1.52; 95% CI: 1.10-2.11, and severe PPD: natural causes MRR 1.42; 95% CI 1.02-2.00, and unnatural causes MRR 5.05; 95% CI: 3.40-7.51. CONCLUSIONS: This first overview of general medical prognosis in PPD shows that women at either end of the spectrum are at increased risk of subsequent chronic medical conditions and overall mortality.

Postpartum psychiatric disorders and subsequent live birth: a population-based cohort study in Denmark.

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.

Incidence of medically treated depression in Denmark among individuals 15-44 years old: a comprehensive overview based on population registers.

OBJECTIVE: Examine the overall incidence of medically treated depression in Denmark among individuals 15-44 years old, and estimate the 5-year cumulative incidence of psychiatric hospital care among individuals treated first in non-hospital-based care. METHODS: We followed all individuals born in Denmark between 1969 and 1998 from age 15 or 2006 (whichever came first) until first depression treatment; death; emigration; or December 31, 2013. Incidence rates were estimated using Poisson regression. Cumulative incidence of hospital care following treatment in non-hospital care was estimated using Kaplan-Meier curves. RESULTS: In this sample of 2 014 760 individuals, incidence rates of depression in non-hospital and hospital-based care in 2012-2013 were 6.6 (95% Confidence Interval: 6.5-6.7) per 1000 person-years and 1.5 (95% CI: 1.5-1.6) per 1000 person-years, respectively. Overall, 85-90% of first medical treatment for depression took place outside of psychiatric hospitals, but a quarter (26.3%) of individuals treated for depression received hospital care initially or within 5 years. Incidence of hospital care was higher in women and younger individuals. CONCLUSIONS: Most medical treatment for depression in Denmark takes place in non-hospital settings. Women and younger individuals are more likely to receive hospital care both initially and within 5 years after first antidepressant treatment.

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.

Comorbidity of autoimmune thyroid disorders and psychiatric disorders during the postpartum period: a Danish nationwide register-based cohort study.

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

Adverse life events increase risk for postpartum psychiatric episodes: A population-based epidemiologic study.

BACKGROUND: Trauma histories may increase risk of perinatal psychiatric episodes. We designed an epidemiological population-based cohort study to explore if adverse childhood experiences (ACE) in girls increases risk of later postpartum psychiatric episodes. METHODS: Using Danish registers, we identified women born in Denmark between January 1980 and December 1998 (129,439 childbirths). Exposure variables were ACE between ages 0 and 15 including: (1) family disruption, (2) parental somatic illness, (3) parental labor market exclusion, (4) parental criminality, (5) parental death, (6) placement in out-of-home care, (7) parental psychopathology excluding substance use, and (8) parental substance use disorder. Primary outcome was first occurrence of in- or outpatient contact 0-6 months postpartum at a psychiatric treatment facility with any psychiatric diagnoses, ICD-10, F00-F99 (N = 651). We conducted survival analyses using Cox proportional hazard regressions of postpartum psychiatric episodes. RESULTS: Approximately 52% of the sample experienced ACE, significantly increasing risk of any postpartum psychiatric diagnosis. Highest risks were observed among women who experienced out-of-home placement, hazard ratio (HR) 2.57 (95% CI: 1.90-3.48). Women experiencing two adverse life events had higher risks of postpartum psychiatric diagnosis HR: 1.88 (95% CI: 1.51-2.36), compared to those with one ACE, HR: 1.24 (95% CI: 1.03-49) and no ACE, HR: 1.00 (reference group). CONCLUSIONS: ACE primarily due to parental psychopathology and disability contributes to increased risk of postpartum psychiatric episodes; and greater numbers of ACE increases risk for postpartum psychiatric illness with an observed dose-response effect. Future work should explore genetic and environmental factors that increase risk and/or confer resilience.

Maternal hypothyroidism in the perinatal period and childhood asthma in the offspring.

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.

Obstetrical, pregnancy and socio-economic predictors for new-onset severe postpartum psychiatric disorders in primiparous women.

BACKGROUND: Childbirth is a potent trigger for the onset of psychiatric illness in women including postpartum depression (PPD) and postpartum psychosis (PP). Medical complications occurring during pregnancy and/or childbirth have been linked to postpartum psychiatric illness and sociodemographic factors. We evaluated if pregnancy and obstetrical predictors have similar effects on different types of postpartum psychiatric disorders. METHOD: A population-based cohort study using Danish registers was conducted in 392 458 primiparous women with a singleton delivery between 1995 and 2012 and no previous psychiatric history. The main outcome was first-onset postpartum psychiatric episodes. Incidence rate ratios (IRRs) were calculated for any psychiatric contact in four quarters for the first year postpartum. RESULTS: PPD and postpartum acute stress reactions were associated with pregnancy and obstetrical complications. For PPD, hyperemesis gravidarum [IRR 2.69, 95% confidence interval (CI) 1.93-3.73], gestational hypertension (IRR 1.84, 95% CI 1.33-2.55), pre-eclampsia (IRR 1.45, 95% CI 1.14-1.84) and Cesarean section (C-section) (IRR 1.32, 95% CI 1.13-1.53) were associated with increased risk. For postpartum acute stress, hyperemesis gravidarum (IRR 1.93, 95% CI 1.38-2.71), preterm birth (IRR 1.51, 95% CI 1.30-1.75), gestational diabetes (IRR 1.42, 95% CI 1.03-1.97) and C-section (IRR 1.36, 95% CI 1.20-1.55) were associated with increased risk. In contrast, risk of PP was not associated with pregnancy or obstetrical complications. CONCLUSIONS: Pregnancy and obstetrical complications can increase the risk for PPD and acute stress reactions but not PP. Identification of postpartum women requiring secondary care is needed to develop targeted approaches for screening and treatment. Future work should focus on understanding the contributions of psychological stressors and underlying biology on the development of postpartum psychiatric illness.

The impact of education, country, race and ethnicity on the self-report of postpartum depression using the Edinburgh Postnatal Depression Scale.

BACKGROUND: Universal screening for postpartum depression is recommended in many countries. Knowledge of whether the disclosure of depressive symptoms in the postpartum period differs across cultures could improve detection and provide new insights into the pathogenesis. Moreover, it is a necessary step to evaluate the universal use of screening instruments in research and clinical practice. In the current study we sought to assess whether the Edinburgh Postnatal Depression Scale (EPDS), the most widely used screening tool for postpartum depression, measures the same underlying construct across cultural groups in a large international dataset. METHOD: Ordinal regression and measurement invariance were used to explore the association between culture, operationalized as education, ethnicity/race and continent, and endorsement of depressive symptoms using the EPDS on 8209 new mothers from Europe and the USA. RESULTS: Education, but not ethnicity/race, influenced the reporting of postpartum depression [difference between robust comparative fit indexes (∆*CFI) 0.01), but not between European countries (∆*CFI < 0.01). CONCLUSIONS: Investigators and clinicians should be aware of the potential differences in expression of phenotype of postpartum depression that women of different educational backgrounds may manifest. The increasing cultural heterogeneity of societies together with the tendency towards globalization requires a culturally sensitive approach to patients, research and policies, that takes into account, beyond rhetoric, the context of a person's experiences and the context in which the research is conducted.

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.

Perinatal psychiatric episodes: a population-based study on treatment incidence and prevalence.

Perinatal psychiatric episodes comprise various disorders and symptom severity, which are diagnosed and treated in multiple treatment settings. To date, no studies have quantified the incidence and prevalence of perinatal psychiatric episodes treated in primary and secondary care, which we aimed to do in the present study. We designed a descriptive prospective study and included information from Danish population registers to study first-time ever and recurrent psychiatric episodes during the perinatal period, including treatment at psychiatric facilities and general practitioners (GPs). This was done for all women who had records of one or more singleton births from 1998 until 2012. In total, we had information on 822 439 children born to 491 242 unique mothers. Results showed first-time psychiatric episodes treated at inpatient facilities were rare during pregnancy, but increased significantly shortly following childbirth (0.02 vs 0.25 per 1000 births). In comparison, first-time psychiatric episodes treated at outpatient facilities were more common, and showed little variation across pregnancy and postpartum. For every single birth resulting in postpartum episodes treated at inpatient psychiatric facilities, 2.5 births were followed by an episode treated at outpatient psychiatric facility and 12 births by GP-provided pharmacological treatment. We interpret our results the following way: treated severe and moderate psychiatric disorders have different risk patterns in relation to pregnancy and childbirth, which suggests differences in the underlying etiology. We further speculate varying treatment incidence and prevalence in pregnancy vs postpartum may indicate that the current Diagnostic and Statistical Manual of Mental Disorders-5 peripartum specifier not adequately describes at-risk periods across moderate and severe perinatal psychiatric episodes.

Pre-eclampsia and first-onset postpartum psychiatric episodes: a Danish population-based cohort study.

BACKGROUND: Recent evidence suggests that postpartum psychiatric episodes may share similar etiological mechanisms with immune-related disorders. Pre-eclampsia is one of the most prevalent immune-related disorders of pregnancy. Multiple clinical features are shared between pre-eclampsia and postpartum psychiatric disorders, most prominently a strong link to first pregnancies. Therefore, we aimed to study if pre-eclampsia is a risk factor for first-onset postpartum psychiatric episodes. METHOD: We conducted a cohort study using the Danish population registry, with a total of 400 717 primiparous women with a singleton delivery between 1995 and 2011. First-lifetime childbirth was the main exposure variable and the outcome of interest was first-onset postpartum psychiatric episodes. The main outcome measures were monthly incidence rate ratios (IRRs), with the period 11-12 months after birth as the reference category. Adjustments were made for age, calendar period, reproductive history, and perinatal maternal health including somatic and obstetric co-morbidity. RESULTS: Primiparous women were at particularly high risk of first-onset psychiatric episodes during the first month postpartum [IRR 2.93, 95% confidence interval (CI) 2.53-3.40] and pre-eclampsia added to that risk (IRR 4.21, 95% CI 2.89-6.13). Having both pre-eclampsia and a somatic co-morbidity resulted in the highest risk of psychiatric episodes during the 3-month period after childbirth (IRR 4.81, 95% CI 2.72-8.50). CONCLUSIONS: We confirmed an association between pre-eclampsia and postpartum psychiatric episodes. The possible explanations for this association, which are not mutually exclusive, include the psychological impact of a serious medical condition such as pre-eclampsia and the neurobiological impact of pre-eclampsia-related vascular pathology and inflammation.

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.

Prevalence of antidepressant use and contacts with psychiatrists and psychologists in pregnant and postpartum women.

OBJECTIVE: We aimed to study prevalence of antidepressant drug use from 12 months prior childbirth to 12 months postpartum and to compare the prevalences with those in a group of women of similar age who did not give birth. We additionally studied prevalences of contacts with private practicing psychiatrists and psychologists during a similar time period. METHOD: Our study population comprised of pregnant women, and their controls were drawn from a 25% sample of the entire Danish population. Information on redeemed prescriptions for antidepressants and referrals to psychiatrists and psychologists was extracted. The outcome measure was period prevalence calculated in 3-month intervals from 12 months before childbirth to 12 months postpartum. RESULTS: In the 2-year observation period around childbirth, 2733 (3.17%) women had one or more prescriptions for an antidepressant and 935 (1.18%) and 1399 (1.76%) were referred to consultations with a psychiatrist or psychologist, respectively. Women giving birth had a markedly lower use of antidepressants compared to controls, with the largest observed difference during third trimester of pregnancy (0.6% vs. 2.20%). CONCLUSION: We found that the prevalence of redeemed prescriptions for antidepressants decreased during pregnancy and increased postpartum. Similar patterns were observed for contacts with private practicing psychiatrists and psychologists.

Filicide in offspring of parents with severe psychiatric disorders: a population-based cohort study of child homicide.

OBJECTIVE: Although rare in absolute terms, risk of homicide is markedly elevated among children of parents with mental disorders. Our aims were to examine risk of child homicide if 1 or both parents had a psychiatric history, to compare effects by parental sex and diagnostic group, and to assess likelihood of child homicide being perpetrated by parents according to their psychiatric history. METHOD: A prospective, register-based cohort study using the entire Danish population born between January 1, 1973, and January 1, 2007, was conducted. Follow-up of the cohort members began on their date of birth and ended on January 1, 2007; their 18th birthday; their date of death; or their date of emigration, whichever came first. We used the Danish national registers from 1973 to 2007 to study homicide risk between children whose parents were previously admitted to a psychiatric hospital, including diagnosis-specific analyses, versus their unexposed counterparts. In addition, we used police records during 2000 to 2005 to examine whether or not 1 of the parents was the perpetrator. Rates of homicide were analyzed using survival analysis. RESULTS: Children of parents previously admitted to a psychiatric hospital had an overall higher risk of being homicide victims (MRR = 8.94; 95% CI, 6.56-12.18). The risk differed according to parental sex and psychiatric diagnosis (ICD-8 and ICD-10 criteria). The absolute risk of homicide was 0.009% if neither parent had been admitted before the birth of their child and 0.051% if 1 of the parents had previously been admitted. During 2000 to 2005, 88% of the child homicide cases were filicide victims. This percentage was not significantly different for parents with a previous psychiatric admission versus those without such a history. CONCLUSIONS: In the large majority of Danish child-homicide cases, a parent was the perpetrator, regardless of whether there had been parental admission to a psychiatric hospital. Children of parents previously admitted had a higher risk of being homicide victims, and risks were especially high in young children whose mothers were hospitalized with affective disorders or schizophrenia. However, the relative risks presented in the current study are based on extremely rare events, and the overwhelming majority of children whose parents have a psychiatric history do not become homicide victims.

Reproductive patterns in psychotic patients.

CONTEXT: Longitudinal epidemiological studies have shown worse outcomes in patients with psychotic disorder than in the general population. The reproductive pattern may be seen as a measure of outcome following psychotic disorder onset, and it may be measured as the rate of child births where the rate is a proxy measure of well-being. OBJECTIVE: To examine reproductive patterns following psychotic disorder onset by comparing the fertility rates of patients with schizophrenia and bipolar disorder with those of other psychiatric patients and the general population, taking into account parental status at disease-onset, time since onset, and the possible effect of abortions-rates. METHODS: A prospective register-based cohort study drawing on the entire Danish population born after 1950. Incidence Rate Ratios (IRRs) of fertility were analysed using survival analysis. RESULTS: Compared with the general population, the lowest first-child fertility rate was found among men (IRR=0.10) and women (IRR=0.18) with schizophrenia. In comparison, bipolar male patients had an IRR=0.32 and female patients an IRR=0.36, while male unipolar patients had an IRR=0.46 and female patients an IRR=0.57. In the group with other psychiatric disorders men had an IRR=0.51 and women an IRR=0.70. CONCLUSIONS: The results of the present study show a selection process where persons with more severe disorders are less likely to become parents. The reduced fertility was strongly influenced by the time since psychiatric disorder onset; thus, the longer the time since onset, the higher the fertility.