Diagnosed eating disorders in Danish registers - incidence, prevalence, mortality, and polygenic risk

Eating disorders are a group of severe and potentially enduring psychiatric disorders associated with increased mortality. Compared to other severe mental illnesses, they have received relatively limited research attention. Epidemiological studies often only report relative measures despite these being difficult to interpret having limited practical use. The aims of this study were to evaluate the incidence and prevalence of diagnosed anorexia nervosa (AN), bulimia nervosa, and eating disorder not otherwise specified recorded in Danish hospital registers and estimate both relative and absolute measures of subsequent mortality - both all-cause and cause-specific in a general nationwide population of 1,667,374 individuals. In a smaller, genetically informed case-cohort sample, the prediction of polygenic scores for AN, body fat percentage, and body mass index on AN prevalence and severity was estimated. Despite males being less likely to be diagnosed with an eating disorder, those that do have significantly increased rates of mortality. AN prevalence was highest for individuals with high AN and low body fat percentage/body mass index polygenic scores.

Identification of women at high risk of postpartum psychiatric episodes: A population-based study quantifying relative and absolute risks following exposure to selected risk factors and genetic liability

BACKGROUND

We quantified relative and absolute risks of postpartum psychiatric episodes (PPE) following risk factors: Young age, past personal or family history of psychiatric disorders, and genetic liability.

METHODS

We conducted a register-based study using the iPSYCH2012 case-cohort sample. Exposures were personal history of psychiatric episodes prior to childbirth, being a young mother (giving birth before the age of 21.5 years), having a family history of psychiatric disorders, and a high (highest quartile) polygenic score (PGS) for major depression. PPE was defined within 12 months postpartum by prescription of psychotropic medication or in- and outpatient contact to a psychiatric facility. We included primiparous women born 1981-1999, giving birth before January 1st, 2016. We conducted Cox regression to calculate hazard ratios (HRs) of PPE, absolute risks were calculated using cumulative incidence functions.

RESULTS

We included 8174 primiparous women, and the estimated baseline PPE risk was 6.9% (95% CI 6.0%-7.8%, number of PPE cases: 2169). For young mothers with a personal and family history of psychiatric disorders, the absolute risk of PPE was 21.6% (95% CI 15.9%-27.8%). Adding information on high genetic liability to depression, the risk increased to 29.2% (95% CI 21.3%-38.4%) for PPE.

CONCLUSIONS

Information on prior personal and family psychiatric episodes as well as age may assist in estimating a personalized risk of PPE. Furthermore, additional information on genetic liability could add even further to this risk assessment.

Risk factors for anorexia nervosa: A population-based investigation of sex differences in polygenic risk and early life exposures

OBJECTIVE

To examine sex differences in risk factors for anorexia nervosa (AN).

METHOD

This population-based study involved 44,743 individuals (6,239 AN cases including 5,818 females and 421 males, and 38,504 controls including 18,818 females and 19,686 males) born in Denmark between May 1981 and December 2009. Follow-up began on the individual's sixth birthday and ended at AN diagnosis, emigration, death, or December 31, 2016, whichever occurred first. Exposures included socioeconomic status (SES), pregnancy, birth, and early childhood factors based on data from Danish registers, and psychiatric and metabolic polygenic risk scores (PRS) based on genetic data. Hazard ratios were estimated using weighted Cox proportional hazards models stratified by sex (assigned at birth), with AN diagnosis as the outcome.

RESULTS

The effects of early life exposures and PRS on AN risk were comparable between females and males. Although we observed some differences in the magnitude and direction of effects, there were no significant interactions between sex and SES, pregnancy, birth, or early childhood exposures. The effects of most PRS on AN risk were highly similar between the sexes. We observed significant sex-specific effects of parental psychiatric history and body mass index PRS, though these effects did not survive corrections for multiple comparisons.

CONCLUSIONS

Risk factors for AN are comparable between females and males. Collaboration across countries with large registers is needed to further investigate sex-specific effects of genetic, biological, and environmental exposures on AN risk, including exposures in later childhood and adolescence as well as the additive effects of exposures.

PUBLIC SIGNIFICANCE

Sex differences in the prevalence and clinical presentation of AN warrant examination of sex-specific risk factors. This population-based study indicates that the effects of polygenic risk and early life exposures on AN risk are comparable between females and males. Collaboration between countries with large registers is needed to further investigate sex-specific AN risk factors and improve early identification of AN.

Are migrants diagnosed with a trauma-related disorder at risk of premature mortality? A register-based cohort study in Denmark

Background

Mental illness is common among refugees displaced by conflict and war. While evidence points to the relatively good health in terms of longevity of migrants resettled in the destination country, less is known about the mortality of the most vulnerable migrants with a trauma-related diagnosis alone and those with an additional comorbid psychotic disorder. This study aimed to provide an overview of the number and mortality of foreign-born individuals diagnosed with Post-Traumatic Stress Disorder or Enduring Personality Change after a Catastrophic Event (PTSD/EPCACE), a psychotic disorder or both.

Methods

A nationwide register-based cohort study, including residents in Denmark, followed from 1 January 1995 to 31 December 2016. The exposure was PTSD/EPCACE and psychotic disorders as well as region of origin. Relative all-cause mortality was estimated using Cox proportional hazards regression models and calculated for migrants with one or both groups of disorders compared to those from the same region without the disorder.

Results

During the study period, 6,580,000 individuals (50.4% women) were included in the cohort. Of these 1,249,654 (50.5% women) died during follow-up. For men and women from the former Yugoslavia, the Middle East and Northern Africa, a PTSD/EPCACE diagnosis alone or with comorbid psychotic disorder was not associated with increased mortality after adjusting for region of origin. A psychotic disorder alone, however, was associated with an increased mortality rate.

Conclusion

Despite the severity of many refugees' traumatic experiences, a diagnosis of a trauma-related psychiatric disorder did not appear to increase the mortality rates.

Associations between parental socioeconomic-, family-, and sibling status and risk of eating disorders in offspring in a Danish national female cohort

OBJECTIVE

Studies on parental socioeconomic status (SES) and family risk factors for eating disorders (EDs) have yielded inconsistent results; however, several studies have identified high parental educational attainment as a risk factor. The aim was to evaluate associations of parental SES and family composition with anorexia nervosa (AN), bulimia nervosa (BN), and eating disorders not otherwise specified (EDNOS) in the offspring, adjusting for parental age and parental mental health.

METHODS

The cohort included women born in Denmark between January 1, 1989 and December 31, 2010, derived from Danish national registers. Each person was followed from their sixth birthday until onset of the disorder of interest or to December 31, 2016. Exposure variables were: childhood SES, defined as individually evaluated parental level of income, occupation, and education; sibling status; and family composition. Outcomes were: AN, BN, EDNOS, and major depressive disorder (MDD), included as a psychiatric comparison disorder. Risks were estimated using Cox proportional hazards.

RESULTS

High parental SES was associated with increased risk of especially AN, and less so BN and EDNOS, in offspring. In comparison, low SES was associated with a higher risk of MDD. No differences between maternal or paternal socioeconomic risk factors were found. Family composition and sibling status showed limited influence on ED risk.

DISCUSSION

SES shows opposite associations with AN than MDD, whereas associations with BN and EDNOS are intermediate. The socioeconomic backdrop of AN differs markedly from that reported in other psychiatric disorders. Whether that is due to genetic and/or environmental factors remains unknown.

PUBLIC SIGNIFICANCE STATEMENT

Parental socioeconomic background (SES) may influence eating disorders risk in offspring somewhat differently than other psychiatric disorders. In Denmark, higher parental SES was associated with increased risk of, particularly, anorexia nervosa (AN). Importantly AN does strike across the SES spectrum. We must ensure that individuals of all backgrounds have equal access to care and are equally likely to be detected and treated appropriately for eating disorders.

The role of early-life family composition and parental socio-economic status as risk factors for obsessive-compulsive disorder in a Danish national cohort

Research on early-life family environment on obsessive-compulsive disorder (OCD) risk is limited, and sex differences have not been sufficiently studied. We investigated early-life family composition and parental socio-economic status (SES) as OCD risk factors while stratifying for sex in a sample of 1,154,067 individuals from the Danish population (7550 of whom had OCD). Data on early-life family composition (birth order, number of siblings, number of parents in household at proband age 6), parental SES at age 6 (parental income, occupation, and education level), history of parental psychiatric illness, and parental age at birth on OCD risk (i.e., an ICD-10 diagnosis of F42.x) were obtained from Danish population registers. Survival analyses using Cox regression were performed with age as the underlying time variable. Analyses were adjusted for calendar time, and differential effect by sex was tested for exposures. We found that birth order and advanced maternal age were risk factors for OCD in males, and being an only child was associated with increased OCD risk in both sexes. Early childhood SES variables including parental education, occupation, and income were associated with OCD risk, and these effects were more pronounced in females. Significant interaction effects for parental education/occupation and the presence of non-OCD psychiatric diagnoses in the proband also emerged. Our results suggest that early-life SES and family composition may be important risk factors for OCD, and heterogeneity in OCD cases in terms of psychiatric comorbidities, as well as sex differences should be carefully examined in relation to risk factors.

Prenatal and perinatal factors and risk of eating disorders

BACKGROUND

Among the most disabling and fatal psychiatric illnesses, eating disorders (EDs) often manifest early in life, which encourages investigations into in utero and perinatal environmental risk factors. The objective of this study was to determine whether complications during pregnancy and birth and perinatal conditions are associated with later eating disorder risk in offspring and whether these associations are unique to EDs.

METHODS

All individuals born in Denmark to Danish-born parents 1989-2010 were included in the study and followed from their 6th birthday until the end of 2016. Exposure to factors related to pregnancy, birth, and perinatal conditions was determined using national registers, as were hospital-based diagnoses of anorexia nervosa (AN), bulimia nervosa, and eating disorder not otherwise specified during follow-up. For comparison, diagnoses of depressive, anxiety, and obsessive-compulsive disorders were also included. Cox regression was used to compare hazards of psychiatric disorders in exposed and unexposed individuals.

RESULTS

1 167 043 individuals were included in the analysis. We found that similar to the comparison disorders, prematurity was associated with increased eating disorder risk. Conversely, patterns of increasing risks of EDs, especially in AN, with increasing parental ages differed from the more U-shaped patterns observed for depressive and anxiety disorders.

CONCLUSIONS

Our results suggest that pregnancy and early life are vulnerable developmental periods when exposures may influence offspring mental health, including eating disorder risk, later in life. The results suggest that some events pose more global transdiagnostic risk whereas other patterns, such as increasing parental ages, appear more specific to EDs.

Psychotic experiences from preadolescence to adolescence: when should we be worried about adolescent risk behaviors?

Psychotic experiences (PE), below the threshold of psychotic disorder, are common in the general population. PE are associated with risk behaviors such as suicidality, non-suicidal self-injury (NSSI) and substance use. However, PE as specific or causal phenomena of these risk behaviors are still debated. We aimed to examine the longitudinal trajectories of PE from preadolescence to adolescence and their associated risk behaviors in adolescence. A total of 1138 adolescents from the Copenhagen Child Cohort 2000 were assessed for PE and risk behaviors (NSSI, suicide ideation and -attempts and substance use) at age 11 and 16 years, along with measures of general psychopathology and depressive symptoms specifically. Self-reported impact of general psychopathology tended to be associated with more PE persistence. PE were associated with all risk behaviors in cross section at both follow-ups. Persistent PE from ages 11 to 16 and incident PE at age 16 were associated with risk behaviors at age 16, whereas remitting PE from age 11 to 16 were not. After adjustment for co-occurring depressive symptoms and general psychopathology, all associations were markedly reduced. After exclusion of preadolescents who already had expressed risk behavior at age 11, PE in preadolescence did not stand out as an independent predictor of incident adolescent risk behaviors. The current study suggests that PE in preadolescence and adolescence may not play a direct causal role regarding NSSI, suicidality, and substance use. However, PE are still useful clinical markers of severity of psychopathology and associated risk behaviors.

Self-harm in women with postpartum mental disorders

BACKGROUND

Women suffering from first onset postpartum mental disorders (PPMD) have a highly elevated risk of suicide. The current study aimed to: (1) describe the risk of self-harm among women with PPMD and (2) investigate the extent to which self-harm is associated with later suicide.

METHODS

We conducted a register-based cohort study linking national Danish registers. This identified women with any recorded first inpatient or outpatient contact to a psychiatric facility within 90 days after giving birth to their first child. The main outcome of interest was defined as the first hospital-registered episode of self-harm. Our cohort consisted of 1 202 292 women representing 24 053 543 person-years at risk.

RESULTS

Among 1554 women with severe first onset PPMD, 64 had a first-ever hospital record of self-harm. Women with PPMD had a hazard ratio (HR) for self-harm of 6.2 (95% CI 4.9-8.0), compared to mothers without mental disorders; but self-harm risk was lower in PPMD women compared to mothers with non-PPMD [HR: 10.1, (95% CI 9.6-10.5)] and childless women with mental disorders [HR: 9.3 (95% CI 8.9-9.7)]. Women with PPMD and records of self-harm had a significantly greater risk for later suicide compared with all other groups of women in the cohort.

CONCLUSIONS

Women with PPMD had a high risk of self-harm, although lower than risks observed in other psychiatric patients. However, PPMD women who had self-harmed constituted a vulnerable group at significantly increased risk of later suicide.

Mental Health Service Use and Psychopharmacological Treatment Following Psychotic Experiences in Preadolescence

OBJECTIVE

Psychotic experiences affect more than 10% of children and often co-occur with nonpsychotic mental disorders. However, longitudinal studies of the outcome of psychotic experiences based on unbiased information on mental health service use and psychotropic medications are scarce. The authors investigated whether psychotic experiences at ages 11-12 predicted a psychiatric diagnosis or treatment with psychotropic medications by ages 16-17.

METHODS

In a longitudinal register-based follow-up study of the Copenhagen Child Cohort 2000, a total of 1,632 children ages 11-12 were assessed for psychotic experiences in face-to-face interviews. The children were also assessed for mental disorders and IQ. National registries provided information on perinatal and sociodemographic characteristics, on psychiatric disorders diagnosed at child and adolescent mental health services, and on prescribed psychotropic medications through ages 16-17.

RESULTS

Among children who had not been previously diagnosed, and after adjustment for sociodemographic and perinatal adversities and IQ, psychotic experiences at ages 11-12 predicted receiving a psychiatric diagnosis in child and adolescent mental health services before ages 16-17 (adjusted hazard ratio=3.13, 95% CI=1.93, 5.07). The risk was increased if the child met criteria for a co-occurring mental disorder (not diagnosed in mental health settings) at baseline compared with no psychotic experiences or diagnosis at baseline (adjusted hazard ratio=7.85, 95% CI=3.94, 15.63), but having psychotic experiences alone still marked a significantly increased risk of later psychiatric diagnoses (adjusted hazard ratio=2.76, 95% CI=1.48, 5.13). Similar patterns were found for treatment with psychotropic medications.

CONCLUSIONS

Psychotic experiences in childhood predict mental health service use and use of psychotropic medications during adolescence. The study findings provide strong evidence that psychotic experiences in preadolescence index a transdiagnostic vulnerability for diagnosed psychopathology in adolescence.

Risk of diabetic complications and subsequent mortality among individuals with schizophrenia and diabetes - a population-based register study

BACKGROUND

Individuals with schizophrenia often develop diabetes, but little is known about their risk of diabetic complications. We aimed to study incidence of registered diabetic complications and subsequent mortality in individuals with schizophrenia and diabetes compared to individuals with diabetes only.

METHODS

We conducted a cohort study using nationwide registers and followed all individuals in the entire Danish population diagnosed with diabetes from 1997 to 2017. Incidence rate ratios (IRR) of diabetic complications, all-cause and cause-specific mortality rate ratios (MRR) were estimated by Cox regression comparing individuals diagnosed with schizophrenia and diabetes to individuals diagnosed only with diabetes.

RESULTS

In a cohort of 239,118 individuals with diagnosed diabetes, the incidence of any diabetic complication was similar in females with schizophrenia and diabetes compared to females with diabetes only; IRR = 0.93 (95%CI: 0.84-1.02), and significantly lower in males; IRR = 0.85 (95%CI: 0.78-0.92). The all-cause mortality for individuals with a diagnosis of a diabetic complication was higher in individuals with schizophrenia and diabetes than in those with diabetes only; MRR = 1.92 (95%CI: 1.65-2.23) for females and MRR = 1.69 (95%CI: 1.49-1.92) for males. Among those without diabetic complications, schizophrenia was also associated with a higher mortality.

CONCLUSIONS

Individuals with schizophrenia and diabetes had similar or lower rates of diabetic complications, compared to those with diabetes only. Among those with diabetic complications, schizophrenia was associated with higher mortality. Similar, among those without diabetic complications, schizophrenia was also associated with higher mortality. Hence, diabetic complications do not seem to explain the excess mortality seen in individuals with schizophrenia.

Childhood infections and schizophrenia: The impact of parental SES and mental illness, and childhood adversities

Childhood infection has been proposed as an important etiologic factor for schizophrenia. However, it is unclear to what extent the association between childhood infection and schizophrenia is confounded by parental socioeconomic status and mental illness, and childhood adversity, and whether the association is explained by familial liability for infections. We used a historical, population-based cohort design, selecting all singletons born in Denmark between 1981 and 1998 (n = 882,813). We identified exposure to infection as having been hospitalized with an infection in the Danish national registers. Data from a range of population-based registers were used to construct a childhood adversity index. The index included the following adversities: family disruption, parental incarceration, parental chronic somatic disease, death of a parent, parent permanently outside of workforce, childhood abuse and placement in out-of-home care. We also assessed parental socioeconomic status and mental illness. Multiple admissions with infections during childhood increased the risk of schizophrenia with an Incidence Rate Ratio (IRR) of 1.28 (95% CI: 1.19-1.38) for 1 infection to an IRR of 1.43 (95% CI: 1.30-1.58) for 2-3 infections and an IRR of 1.95 (95% CI: 1.66-2.29) for ≥4 infections. Parental socioeconomic status and mental illness, and childhood adversities increased the odds of acquiring childhood infections and was associated with schizophrenia, but did not explain the results. Similarly did familial liability for infection increase the risk of schizophrenia, but did not explain the association between infection and schizophrenia. Parental mental health modified the association between childhood infection and schizophrenia (p-value 0.02), and we found no significant effect of childhood infection in those with propensity for psychotic disorders.

Association of Exposure to Infections in Childhood With Risk of Eating Disorders in Adolescent Girls

IMPORTANCE

Infections are recognized as playing a critical role in the risk of psychiatric disorders and suicidal behavior; however, few studies have evaluated the risk of eating disorders.

OBJECTIVE

To evaluate the association of hospitalization for infections and treatment with anti-infective agents with the risk of an eating disorder diagnosis.

DESIGN, SETTING, AND PARTICIPANTS

A nationwide, population-based, prospective cohort study of 525 643 girls born from January 1, 1989, to December 31, 2006, and followed up until December 31, 2012, was conducted using individual-level data drawn from Danish longitudinal registers. Data were analyzed from January 15 to June 15, 2018, using survival analysis models and adjusted for age, calendar period, parental educational level, and parental history of psychiatric illness.

EXPOSURES

Hospital admission for infections and prescribed anti-infective agents for infections.

MAIN OUTCOMES AND MEASURES

The main outcome of interest was diagnosis of an eating disorder (anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified) in a hospital, outpatient clinic, or emergency department setting. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and accompanying 95% CIs.

RESULTS

The study population consisted of 525 643 adolescent girls: 2131 received a diagnosis of anorexia nervosa (median [range] age, 15.2 [8.6-21.3] years), 711 received a diagnosis of bulimia nervosa (median [range] age, 17.9 [13.4-22.7] years), and 1398 received a diagnosis of an eating disorder not otherwise specified (median [range] age, 15.6 [8.6-21.6] years). A total of 525 643 adolescent girls were followed up for 4 601 720.4 person-years until a mean age of 16.2 years (range, 10.5-22.7 years). Severe infections that required hospitalization were associated with an increased risk of a subsequent diagnosis of anorexia nervosa by 22% (HR, 1.22; 95% CI, 1.10-1.35), bulimia nervosa by 35% (HR, 1.35; 95% CI, 1.13-1.60), and eating disorder not otherwise specified by 39% (HR, 1.39; 95% CI, 1.23-1.57) compared with adolescent girls without hospitalizations for infections. Infections treated with anti-infective agents were associated with an increased risk of a subsequent diagnosis of anorexia nervosa by 23% (HR, 1.23; 95% CI, 1.10-1.37), bulimia nervosa by 63% (HR, 1.63; 95% CI, 1.32-2.02), and eating disorder not otherwise specified by 45% (HR, 1.45; 95% CI, 1.25-1.67) compared with adolescent girls without infections treated with anti-infective agents.

CONCLUSIONS AND RELEVANCE

The findings suggest that hospital-treated infections and less severe infections treated with anti-infective agents are associated with increased risk of subsequent anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified and that future studies should investigate whether these associations are causal and identify the exact mechanisms between infections and subsequent inflammatory processes with eating disorders.

Sex Differences in Comorbidity Patterns of Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

To investigate sex differences in associations between attention-deficit/hyperactivity disorder (ADHD) and a spectrum of comorbid disorders.

METHOD

The study population included all children born in Denmark from 1981 through 2013 (N = 1,665,729). Data were merged from Danish registers and information was obtained on birth characteristics, socioeconomic status, familial psychiatric history, and diagnoses of ADHD (n = 32,308) and comorbid disorders. To estimate absolute and relative risks of comorbid disorders, incidence rates and adjusted hazard ratios (HRs) with 95% CIs were calculated for female and male individuals. In addition, interactions between ADHD and sex in association with comorbid disorders were estimated as HR ratios (HRRs) in female and male individuals (95% CIs).

RESULTS

Individuals diagnosed with ADHD had significantly increased absolute and relative risks of all 12 comorbid psychiatric disorders investigated. ADHD-sex interactions were found for some comorbid disorders. Compared with male individuals, ADHD in female individuals showed a stronger association with autism spectrum disorder (HRR 1.86, 95% CI 1.62-2.14), oppositional defiant/conduct disorder (HRR 1.97, 95% CI 1.68-2.30), intellectual disability (HRR 1.79, 95% CI 1.54-2.09), personality disorders (HRR 1.23, 95% CI 1.06-1.43), schizophrenia (HRR 1.21, 95% CI 1.02-1.43), substance use disorders (HRR 1.21, 95% CI 1.07-1.38), and suicidal behavior (1.28, 95% CI 1.12-1.47). The remaining disorders showed no significant sex differences in association with ADHD.

CONCLUSION

This study indicates that the association between ADHD and several comorbid disorders is stronger in female than in male individuals. These important findings add to the literature on sex differences in ADHD and suggest that female individuals diagnosed with ADHD are a more vulnerable group of patients.

Psychosocial Adversity in Infancy and Mortality Rates in Childhood and Adolescence: A Birth Cohort Study of 1.5 Million Individuals

BACKGROUND

Childhood and adolescent mortality accounts for a substantial proportion of years lost prematurely. Reducing childhood and adolescent mortality relies on knowing characteristics of those at elevated risk of dying young. We therefore aimed to identify such characteristics; our main hypothesis is that psychosocial adversity in infancy is linked to increased mortality rates in childhood and adolescence.

METHODS

We conducted a register-based cohort study involving all 1,549,581 children born to Danish-born parents in Denmark between 1 January 1981 and 31 December 2010. For each infant, we extracted data relevant to Rutter's indicators of adversity (low social class, parents not cohabiting, large family size, paternal criminality, maternal mental disorder, and placement in out-of-home care). Follow-up began on the cohort member's first birthday. We estimated the association between adversity score (the number of Rutter's indicators of adversity present in infancy) and death via. Cox regression.

RESULTS

During follow-up (18,874,589 person-years), 2,081 boys and 1,420 girls died before or on their 18th birthday. The hazard ratios for death were 2.3 (95% CI = 1.9, 2.9) and 2.1 (95% CI = 1.6, 2.7) for boys and girls with adversity scores of 3-6 compared with those with a score of 0. These associations were driven by causes of death with known links to psychosocial adversity.

CONCLUSION

While absolute mortality rates were low, infants with adversity scores of 3-6 were approximately twice as likely to die prematurely compared with infants with adversity scores of 0. Whether these associations generalize to other countries should be subjected to further study.

A Danish register-based study on involuntary treatment in anorexia nervosa

OBJECTIVE

Involuntary treatment is controversial and widely debated, but remains a significant component of treatment for severe anorexia nervosa. Given how little is known about this topic, we describe the frequency of various involuntary measures in a national cohort of all patients diagnosed with anorexia nervosa. In a subsample of patients, we explored predictors of the first involuntary measure recorded.

METHOD

Descriptive statistics and Cox proportional hazard analyses were conducted using the national registers of Denmark covering the total population. Data from the National Patient Register and the Psychiatric Central Research Register including all psychiatric visits from 1969 onwards were merged with data from the National Register on Coercion covering 1999 onward. Involuntary measures registered between 2000 and 2013 were analyzed.

RESULTS

A total of 4,727 patients with a diagnosis of anorexia nervosa representing 16,592 admissions were included. Eighteen percent experienced at least one involuntary measure. A variety of measures were used with tube feeding being the most frequent followed by mechanical restraint, involuntary medication, physical restraint, constant observation, and sedative medication. A subsample of 2% of AN patients had more than 100 involuntary measures recorded. The first recorded involuntary measure was predicted by most but not all psychiatric comorbidities, especially schizophrenia, autism spectrum, and personality disorders, older age at first diagnosis, and previous admissions.

DISCUSSION

It is important to develop a more granular understanding of patients at risk of requiring involuntary treatment and to determine how best to treat them effectively with minimal use of involuntary measures.

Accidental deaths among persons with schizophrenia: A nationwide population-based cohort study

OBJECTIVES

Persons with schizophrenia have a shorter life expectancy by 15-20years compared to the background population, but little is known about deaths caused by accidents. We aimed to investigate the rates of accidental death among persons with schizophrenia and compare these rates with those of the background population.

METHODS

We conducted a national register-based cohort study of all persons born in Denmark between 1955 and 2011. The cohort included 2,703,307 persons, representing 56,845,085 person years at risk. We compared rates of accidental death between persons with schizophrenia and those without by using Cox regression analysis. The main outcome measure was hazard ratio (HR) for accidental death.

RESULTS

A total of 12,425 accidental deaths were identified, including 371 accidental deaths among persons with schizophrenia. We found an increased HR for both women with schizophrenia (10.47; 95% CI=8.07-13.58) and men with schizophrenia (8.33; 95% CI=7.44-9.33) compared to the background population. After adjusting for substance abuse, we found attenuated HRs for both women (HR=3.22; 95% CI=2.46-4.20) and men (HR=3.23; 95% CI=2.87-3.63).

CONCLUSIONS

Schizophrenia is a strong independent risk factor for accidental deaths. Substance abuse seems to constitute a substantial part of the association.

Eating Disorders, Autoimmune, and Autoinflammatory Disease

OBJECTIVES

Identifying factors associated with risk for eating disorders is important for clarifying etiology and for enhancing early detection of eating disorders in primary care. We hypothesized that autoimmune and autoinflammatory diseases would be associated with eating disorders in children and adolescents and that family history of these illnesses would be associated with eating disorders in probands.

METHODS

In this large, nationwide, population-based cohort study of all children and adolescents born in Denmark between 1989 and 2006 and managed until 2012, Danish medical registers captured all inpatient and outpatient diagnoses of eating disorders and autoimmune and autoinflammatory diseases. The study population included 930 977 individuals (48.7% girls). Cox proportional hazards regression models and logistic regression were applied to evaluate associations.

RESULTS

We found significantly higher hazards of eating disorders for children and adolescents with autoimmune or autoinflammatory diseases: 36% higher hazard for anorexia nervosa, 73% for bulimia nervosa, and 72% for an eating disorder not otherwise specified. The association was particularly strong in boys. Parental autoimmune or autoinflammatory disease history was associated with significantly increased odds for anorexia nervosa (odds ratio [OR] = 1.13, confidence interval [CI] = 1.01-1.25), bulimia nervosa (OR = 1.29; CI = 1.08-1.55) and for an eating disorder not otherwise specified (OR = 1.27; CI = 1.13-1.44).

CONCLUSIONS

Autoimmune and autoinflammatory diseases are associated with increased risk for eating disorders. Ultimately, understanding the role of immune system disturbance for the etiology and pathogenesis of eating disorders could point toward novel treatment targets.

Early childhood adversities and risk of eating disorders in women: A Danish register-based cohort study

OBJECTIVE

Previous studies evaluating the association between early childhood adversities and eating disorders have yielded conflicting results. The aim of this study is to examine the association between a range of adversities and risk of anorexia nervosa (AN), bulimia nervosa (BN), and eating disorder not otherwise specified (EDNOS) in 495,244 women.

METHOD

In this nationwide, register-based cohort study, nine types of early childhood adversity (family disruption, residential instability, placement in out-of-home care, familial death, parental somatic illness, parental psychiatric illness, parental disability, severe parental criminality, and parental substance use disorder) were defined and exposure during the first 6 years of life was determined. Hazard ratios for eating disorders were calculated using Cox regression.

RESULTS

Few adversities were significantly associated with AN, and for each, the presence of the adversity was associated with lower risk for AN. BN, and EDNOS were positively associated with several types of adversities. AN rates were unchanged or reduced by up to 54% by adversities, whereas rates of BN and EDNOS were unchanged or increased by adversities by up to 49 and 89%, respectively.

DISCUSSION

Our findings indicate that childhood adversities appear to be associated with an increased risk of BN and in particular EDNOS, whereas they seem to be either unassociated or associated with a decreased risk of AN.

Early adversity and risk for moderate to severe unipolar depressive disorder in adolescence and adulthood: A register-based study of 978,647 individuals

BACKGROUND

Early adversity is a known risk factor for unipolar depression. We examined the impact of 9 types of early adversity on risk for moderate to severe unipolar depression in adolescence or adulthood, and evaluated whether these effects were moderated by gender and adversity timing.

METHODS

We conducted a prospective, population-based cohort study using Danish national registers. The sample included all individuals born in Denmark between 1980 and 1998 (N=978,647). Exposure to early adversity was assessed from ages 0-15. Types of adversity included parental illness, incarceration, death, disability, and psychiatric diagnosis; family disruption; out-of-home care; and childhood abuse. Individuals were followed from age 15 until first in- or outpatient depression diagnosis (ICD-10 codes F32, F33) in a psychiatric hospital, death, emigration, or December 31st, 2013, whichever came first. Hazard ratios (HRs) were calculated using Cox regressions.

RESULTS

All adversities were significantly associated with increased risk for moderate to severe adolescent/adult depression (HR range: 1.30-2.72), although the effects were attenuated after mutual adjustment (adjusted HR range: 1.06-1.70). None of the effects were moderated by gender. The effect of family disruption was strongest between ages 0-4 (HR=1.66, 95% CI=1.61-1.71), while the effect of out-of-home care was strongest between ages 10-14 (HR=2.45, 95% CI=2.28-2.64).

LIMITATIONS

Untreated and primary-care treated depression were not measured.

CONCLUSIONS

Our results support past findings that multiple types of early adversity increase risk for moderate to severe unipolar depression in adolescence and adulthood. Certain adversities may be more harmful if they occur during specific developmental time periods.

Joint Effects of Exposure to Prenatal Infection and Peripubertal Psychological Trauma in Schizophrenia

CONTEXT

Prenatal infection and traumatizing experiences have both been linked with schizophrenia, but none of these factors seem sufficient to cause the disorder. However, recent evidence suggests that these environmental insults act in synergy to increase schizophrenia risk.

OBJECTIVE

To estimate the independent and joint effects of exposure to prenatal infection and peripubertal psychological trauma on the risk of schizophrenia.

DESIGN

Danish nationwide registers were linked in this prospective cohort study. We used survival analysis to report incidence rate ratios (IRRs) and corresponding 95% confidence intervals (95% CIs). Analyses were adjusted for age and calendar period and stratified by sex.

PARTICIPANTS

A total of 979701 persons born between 1980 and 1998 were followed up from January 1, 1995 through December 31, 2013, with 9656 having a hospital contact for schizophrenia.

RESULTS

Females exposed to prenatal infection had a significantly increased risk of schizophrenia (IRR: 1.61, 95% CI: 1.30-2.00), but not males (IRR: 0.99, 95% CI: 0.77-1.28). Peripubertal trauma was associated with increased risk in both sexes. Males, however, had a significantly higher risk of schizophrenia after exposure to both prenatal infection and peripubertal psychological trauma (IRR: 2.85, 95% CI: 2.32-3.51), with significant interaction between infection and peripubertal trauma on the multiplicative scale (P = .007).

CONCLUSIONS

Our study demonstrated for the first time that prenatal infection and psychological trauma in peripubertal life can act in synergy to increase the risk of schizophrenia, with a potentially stronger susceptibility in males.

Introducing the White Noise task in childhood: associations between speech illusions and psychosis vulnerability

BACKGROUND

Auditory verbal hallucinations (AVH) are common during development and may arise due to dysregulation in top-down processing of sensory input. This study was designed to examine the frequency and correlates of speech illusions measured using the White Noise (WN) task in children from the general population. Associations between speech illusions and putative risk factors for psychotic disorder and negative affect were examined.

METHOD

A total of 1486 children aged 11-12 years of the Copenhagen Child Cohort 2000 were examined with the WN task. Psychotic experiences and negative affect were determined using the Kiddie-SADS-PL. Register data described family history of mental disorders. Exaggerated Theory of Mind functioning (hyper-ToM) was measured by the ToM Storybook Frederik.

RESULTS

A total of 145 (10%) children experienced speech illusions (hearing speech in the absence of speech stimuli), of which 102 (70%) experienced illusions perceived by the child as positive or negative (affectively salient). Experiencing hallucinations during the last month was associated with affectively salient speech illusions in the WN task [general cognitive ability: adjusted odds ratio (aOR) 2.01, 95% confidence interval (CI) 1.03-3.93]. Negative affect, both last month and lifetime, was also associated with affectively salient speech illusions (aOR 2.01, 95% CI 1.05-3.83 and aOR 1.79, 95% CI 1.11-2.89, respectively). Speech illusions were not associated with delusions, hyper-ToM or family history of mental disorders.

CONCLUSIONS

Speech illusions were elicited in typically developing children in a WN-test paradigm, and point to an affective pathway to AVH mediated by dysregulation in top-down processing of sensory input.

Childhood Epilepsy, Febrile Seizures, and Subsequent Risk of ADHD

OBJECTIVES

Epilepsy, febrile seizures, and attention-deficit/hyperactivity disorder (ADHD) are disorders of the central nervous system and share common risk factors. Our goal was to examine the association in a nationwide cohort study with prospective follow-up and adjustment for selected confounders. We hypothesized that epilepsy and febrile seizures were associated with subsequent ADHD.

METHODS

A population-based cohort of all children born in Denmark from 1990 through 2007 was followed up until 2012. Incidence rate ratios (IRRs) and 95% confidence intervals (95% CIs) for ADHD were estimated by using Cox regression analysis, comparing children with epilepsy and febrile seizure with those without these disorders, adjusted for socioeconomic and perinatal risk factors, as well as family history of neurologic and psychiatric disorders.

RESULTS

A total of 906 379 individuals were followed up for 22 years (∼10 million person-years of observation); 21 079 individuals developed ADHD. Children with epilepsy had a fully adjusted IRR of ADHD of 2.72 (95% CI, 2.53-2.91) compared with children without epilepsy. Similarly, in children with febrile seizure, the fully adjusted IRR of ADHD was 1.28 (95% CI, 1.20-1.35). In individuals with both epilepsy and febrile seizure, the fully adjusted IRR of ADHD was 3.22 (95% CI, 2.72-3.83).

CONCLUSIONS

Our findings indicate a strong association between epilepsy in childhood and, to a lesser extent, febrile seizure and subsequent development of ADHD, even after adjusting for socioeconomic and perinatal risk factors, and family history of epilepsy, febrile seizures, or psychiatric disorders.

Evolving changes in disease biomarkers and risk of early progression in smoldering multiple myeloma

We studied 190 patients with smoldering multiple myeloma (SMM) at our institution between 1973 and 2014. Evolving change in monoclonal protein level (eMP) was defined as ⩾10% increase in serum monoclonal protein (M) and/or immunoglobulin (Ig) (M/Ig) within the first 6 months of diagnosis (only if M-protein ⩾3 g/dl) and/or ⩾25% increase in M/Ig within the first 12 months, with a minimum required increase of 0.5 g/dl in M-protein and/or 500 mg/dl in Ig. Evolving change in hemoglobin (eHb) was defined as ⩾0.5 g/dl decrease within 12 months of diagnosis. A total of 134 patients (70.5%) progressed to MM over a median follow-up of 10.4 years. On multivariable analysis adjusting for factors known to predict for progression to MM, bone marrow plasma cells ⩾20% (odds ratio (OR)=3.37 (1.30-8.77), P=0.013), eMP (OR=8.20 (3.19-21.05), P<0.001) and eHb (OR=5.86 (2.12-16.21), P=0.001) were independent predictors of progression within 2 years of SMM diagnosis. A risk model comprising these variables was constructed, with median time to progression of 12.3, 5.1, 2.0 and 1.0 years among patients with 0-3 risk factors respectively. The 2-year progression risk was 81.5% in individuals who demonstrated both eMP and eHb, and 90.5% in those with all three risk factors.

All-Cause Mortality in Women With Severe Postpartum Psychiatric Disorders

OBJECTIVE

The postpartum period is associated with a high risk of psychiatric episodes. The authors studied mortality in women with first-onset severe psychiatric disorders following childbirth and compared their mortality rates with those in women from the background population including other female psychiatric patients (mothers and childless women).

METHOD

In a register-based cohort study with linked information from Danish population registers, the authors identified women with first psychiatric inpatient or outpatient contacts 0-3 months postpartum. The main outcome measure was mortality rate ratios (MRRs): deaths from natural causes (diseases and medical conditions) or unnatural causes (suicides, accidents, and homicides). The cohort included 1,545,857 women representing 68,473,423 person-years at risk.

RESULTS

In total, 2,699 women had first-onset psychiatric disorders 0-3 months postpartum, and 96 of these died during follow-up. Women with postpartum psychiatric disorders had a higher MRR (3.74; 95% CI=3.06-4.57) than non-postpartum-onset mothers (MRR=2.73; 95% CI=2.67-2.79) when compared with mothers with no psychiatric history. However, childless women with psychiatric diagnoses had the highest MRR (6.15; 95% CI=5.94-6.38). Unnatural cause of death represented 40.6% of fatalities among women with postpartum psychiatric disorders, and within the first year after diagnosis, suicide risk was drastically increased (MRR=289.42; 95% CI=144.02-581.62) when compared with mothers with no psychiatric history.

CONCLUSIONS

Women with severe postpartum psychiatric disorders had increased MRRs compared with mothers without psychiatric diagnoses, and the first year after diagnosis represents a time of particularly high relative risk for suicide in this vulnerable group.

Gender Differences in Associations Between Attention-Deficit/Hyperactivity Disorder and Substance Use Disorder

OBJECTIVE

To examine gender differences in the association between attention-deficit/hyperactivity disorder (ADHD) and substance use disorder (SUD), and to explore the impact of comorbid psychiatric conditions.

METHOD

This was a cohort study of all children born in Denmark in 1990 to 2003 (n = 729,560). By record linkage across nationwide registers, we merged data on birth characteristics, socioeconomic status, familial psychiatric history, and diagnoses of ADHD (N = 19,645), comorbidities, and SUD. Hazard ratios (HR) with 95% CIs were estimated by Cox regression and adjusted for a range of variables.

RESULTS

ADHD increased the risk of alcohol abuse (HRfemales = 1.72 [95% CI = 1.42-2.08], HRmales = 1.57 [1.37-1.79]), cannabis abuse (HRfemales = 2.72 [2.12-3.47], HRmales = 2.24 [1.86-2.70]), and other illicit substance abuse (HRfemales = 2.05 [1.54-2.73], HRmales = 2.42 [1.98-2.96]), compared to individuals without ADHD. In the overall estimates, no gender differences were found. Among individuals with ADHD without comorbidities, females had a higher SUD risk than males, as did females with ADHD and conduct disorder (CD). Comorbid CD, depression, bipolar disorder, and schizophrenia further increased the risk of SUD in ADHD, compared to non-ADHD. Autism spectrum disorder in males with ADHD lowered the SUD risk.

CONCLUSION

ADHD increased the risk of all SUD outcomes. Individuals with ADHD without comorbidities were also at increased risk, and some comorbid disorders further increased the risk. Females and males with ADHD had comparable risks of SUD, although females had higher risk of some SUDs than males. Females with ADHD may be perceived as less impaired than males, but they are at equally increased risk of SUD.

The CCC2000 Birth Cohort Study of Register-Based Family History of Mental Disorders and Psychotic Experiences in Offspring

Psychotic experiences (PE) in individuals of the general population are hypothesized to mark the early expression of the pathology underlying psychosis. This notion of PE as an intermediate phenotype is based on the premise that PE share genetic liability with psychosis. We examined whether PE in childhood was predicted by a family history of mental disorder with psychosis rather than a family history of nonpsychotic mental disorder and whether this association differed by severity of PE. The study examined data on 1632 children from a general population birth cohort assessed at age 11-12 years by use of a semistructured interview covering 22 psychotic symptoms. The Danish national registers were linked to describe the complete family history of hospital-based psychiatric diagnoses. Uni- and multivariable logistic regressions were used to test whether a family history of any mental disorder with psychosis, or of nonpsychotic mental disorder, vs no diagnoses was associated with increased risk of PE in offspring (hierarchical exposure variable). The occurrence of PE in offspring was significantly associated with a history of psychosis among the first-degree relatives (adjusted relative risk [RR] = 3.29, 95% CI: 1.82-5.93). The risk increased for combined hallucinations and delusions (adjusted RR = 5.90, 95% CI: 2.64-13.16). A history of nonpsychotic mental disorders in first-degree relatives did not contribute to the risk of PE in offspring nor did any mental disorder among second-degree relatives. Our findings support the notion of PE as a vulnerability marker of transdiagnostic psychosis. The effect of psychosis in first-degree relatives may operate through shared genetic and environmental factors.

Incidence of eating disorders in Danish psychiatric secondary healthcare 1970-2008

OBJECTIVE

Is an increased focus on eating disorders during the past few decades reflected by increasing occurrence in the psychiatric health service system.

METHOD

All first-time diagnoses of eating disorders identified in the Danish Central Psychiatric Research Register 1970-2008 constitute the present research database. Age-standardized rates per 100,000 inhabitants were calculated and autoregressive models were fitted for males and females separately as well as for in- and outpatients.

RESULTS

The incidence of eating disorders diagnosed in Danish psychiatric secondary healthcare has increased considerably during a nearly 40-year period of observation both within the general category of eating disorders and also specifically for anorexia nervosa. The steepest increase is seen within females aged 15-19 years, where the highest incidences are also found. Anorexia nervosa constitutes the vast majority of all eating disorders. Throughout the time interval investigated, the number of males, however, is negligible compared to females. Most patients are seen in outpatient services, increasing towards recent years. However, the number of patients being treated as inpatients has increased linearly through the entire four decenniums investigated.

CONCLUSIONS

Changes in registration principles, public awareness and higher acceptance of mental disorders in the public is the most obvious explanation for the incidence increase of anorexia nervosa and other eating disorders. This study does not answer whether there has been an increase in true incidence in the population.

The incidence of eating disorders in a Danish register study: Associations with suicide risk and mortality

Our aim was to characterize the incidence rates and cumulative incidence of anorexia nervosa (AN), bulimia nervosa (BN), and eating disorder not otherwise specified (EDNOS), and examine associations among eating disorder diagnoses, suicide attempts, and mortality. Individuals born in Denmark between 1989 and 2006 were included (N = 966,141, 51.3% male). Eating disorders diagnoses (AN, broad AN, BN, EDNOS) were drawn from the Danish Psychiatric Central Research Register (PCRR) and Danish National Patient Register (NPR). Suicide attempts and deaths were captured in the NPR, the PCRR, and the Danish Civil Registration System (CRS). In females, AN had a peak hazard at approximately age 15 years, BN at 22 years, and EDNOS had an extended peak that spanned 18 years-22 years. Eating disorder diagnoses predicted a significantly higher hazard for death and suicide attempt compared with the referent of individuals with no eating disorders. In males, peak hazard for diagnosis was earlier than in females. The present study represents one of the largest and longest studies of eating disorder incidence and suicide attempts and death in both females and males. Eating disorders are accompanied by increased hazard of suicide attempts and death even in young adults.

Delay in blood sampling for routine newborn screening is associated with increased risk of schizophrenia

BACKGROUND

The Danish Neonatal Screening Biobank, containing dried blood spot samples from all newborn in Denmark, is a unique source of data that can be utilized for analyses of genetic and environmental exposures related to schizophrenia and other mental disorders. In previous analyses, we have found that early and late blood sampling, compared to sampling at day 5, was associated with increased risk of schizophrenia. As delay in sampling of blood for neonatal screening cannot in itself influence the risk of schizophrenia, it must be seen as a proxy for unknown underlying causes responsible for this association. Therefore, we investigated whether the increased risk can be explained by other risk factors for schizophrenia.

METHODS

A case-control design was applied. A total of 846 cases with schizophrenia were selected from the Danish Psychiatric Case Register. One control was selected for each case, matched on sex and exact date of birth.

RESULTS

Both early and late blood sampling was associated with increased risk for schizophrenia. Compared to blood sampling at day 5, sampling at days 0 to 4 after birth was associated with an incidence rate ratio (IRR) of 1.46 (95% CI 1.15-1.87) for development of schizophrenia, and sampling at days 6 to 9 and at days 10 to 53 was associated with an IRR of 1.5 (95% CI 1.13-1.98) and 3.00 (95% CI 1.59-5.67), respectively. After adjusting the estimates for place of birth, both parents' psychiatric illness, maternal and paternal age, parents' country of origin, child admission, and parental education and income, the estimates were slightly different. Thus, blood collection at 0-4days was associated with an IRR of 1.27 (95% CI 0.94-1.71), 6-9days 1.31 (95% CI 0.94-1.84) and 10+days 3.52 (95% CI 1.50 to 8.24).

DISCUSSION

After adjusting risk estimates for well-known risk factors, delay in sampling of blood for neonatal screening was associated with unexplained increased risk of schizophrenia. Thus, a key finding is that age at test is a proxy for unobserved risk factors for schizophrenia due to unexplained reasons for late blood sampling. Date of sampling will be included in future analyses of genetic and environmental risk factors.

Can people feel happy and sad at the same time?

The authors investigated whether people can feel happy and sad at the same time. J. A. Russell and J. M. Carroll's (1999) circumplex model holds that happiness and sadness are polar opposites and, thus, mutually exclusive. In contrast, the evaluative space model (J. T. Cacioppo & G. G. Berntson, 1994) proposes that positive and negative affect are separable and that mixed feelings of happiness and sadness can co-occur. The authors both replicated and extended past research by showing that whereas most participants surveyed in typical situations felt either happy or sad, many participants surveyed immediately after watching the film Life Is Beautiful, moving out of their dormitories, or graduating from college felt both happy and sad. Results suggest that although affective experience may typically be bipolar, the underlying processes, and occasionally the resulting experience of emotion, are better characterized as bivariate.

[Clozapine-induced toxic hepatitis]

A case of clozapine-induced toxic hepatitis in a 49-year old woman with schizophrenia is described. The daily clozapine dose was clinically titrated to 300 mg. Subsequently, the patient experienced lethargy and anorexia, and fever, eosinophilia, leucocytosis and abnormal liver parameters were found. The serum concentration of clozapine was 8595 nmol/l, and treatment was discontinued. After eight days, the condition stabilised, and low-dose clozapine treatment was successfully reinstituted with serum monitoring (TDM).

Tacrine is not an ideal probe drug for measuring CYP1A2 activity in vivo

AIMS

The aim of the present study was to examine the CYP1A2 substrate tacrine as a possible alternative to caffeine for assessing CYP1A2 activity in vivo.

METHODS

Eighteen, healthy, nonsmoking men participated. Each volunteer was tested by caffeine (200 mg orally), and caffeine metabolic ratios were calculated. Subsequently, on two occasions, separated by at least 4 weeks, each volunteer was tested with tacrine (40 mg orally). The apparent oral clearance, partial clearances and different metabolic ratios of tacrine were determined.

RESULTS

The median oral clearances of tacrine in the two study periods were 1893 l h-1 (range: 736-3098) and 1890 l h-1 (range: 438-4175), respectively. The interindividual coefficient of variation was 42% and 49%, respectively. The intraindividual coefficients of variation ranged from 0.28% to 64% (median: 13%). In both study periods, the oral clearance of tacrine correlated with the caffeine urinary metabolic ratio. However, only modest magnitudes of correlation were observed (rs: 0.64-0.66, P<0. 01). No tacrine metabolic ratio correlating with the oral clearance of tacrine was found. Conclusion The applicability of tacrine as a probe drug for measuring CYP1A2 activity in vivo appears limited.

Fluvoxamine is a potent inhibitor of tacrine metabolism in vivo

OBJECTIVE

In vitro studies have shown that tacrine is metabolized by cytochrome P4501A2 (CYP1A2). One of the monohydroxy-metabolites has been incriminated with tacrine-induced hepatotoxicity. The aim of this study was to establish whether the potent CYP1A2 inhibitor fluvoxamine in clinically relevant doses could inhibit tacrine metabolism.

METHODS

Eighteen healthy young men were enrolled in an open, randomized crossover study. In the first study period a single oral dose of tacrine 40 mg was given. In the second period the volunteers were randomized to maintenance doses of fluvoxamine 50 or 100 mg per day, and a single oral dose of tacrine 20 mg was given.

RESULTS

Fluvoxamine was found to be a very potent inhibitor of tacrine metabolism. A fractional decrement in tacrine clearance of approximately 85% was found with both fluvoxamine doses, which was in good agreement with a prediction based on in vitro data. The medians of the steady-state concentration of fluvoxamine were 43 nM (range 25-49) and 70 nM (range 44-124) in the 50 mg per day and 100 mg per day groups, respectively. The steady-state concentration of fluvoxamine correlated with the fractional decrement in tacrine clearance (Spearman Rs = 0.53, P < 0.05). Modest, but statistically significant, reductions in the formation of the metabolites 1- and 2-hydroxytacrine were found during concomitant fluvoxamine treatment.

CONCLUSION

Fluvoxamine at clinically relevant doses is a potent inhibitor of tacrine metabolism. This interaction is very likely to have clinical relevance. Whether concomitant fluvoxamine treatment reduces tacrine-induced hepatotoxicity needs further study.

Negative information weighs more heavily on the brain: the negativity bias in evaluative categorizations

Negative information tends to influence evaluations more strongly than comparably extreme positive information. To test whether this negativity bias operates at the evaluative categorization stage, the authors recorded event-related brain potentials (ERPs), which are more sensitive to the evaluative categorization than the response output stage, as participants viewed positive, negative, and neutral pictures. Results revealed larger amplitude late positive brain potentials during the evaluative categorization of (a) positive and negative stimuli as compared with neutral stimuli and (b) negative as compared with positive stimuli, even though both were equally probable, evaluatively extreme, and arousing. These results provide support for the hypothesis that the negativity bias in affective processing occurs as early as the initial categorization into valence classes.

Negative information weighs more heavily on the brain: the negativity bias in evaluative categorizations

Negative information tends to influence evaluations more strongly than comparably extreme positive information. To test whether this negativity bias operates at the evaluative categorization stage, the authors recorded event-related brain potentials (ERPs), which are more sensitive to the evaluative categorization than the response output stage, as participants viewed positive, negative, and neutral pictures. Results revealed larger amplitude late positive brain potentials during the evaluative categorization of (a) positive and negative stimuli as compared with neutral stimuli and (b) negative as compared with positive stimuli, even though both were equally probable, evaluatively extreme, and arousing. These results provide support for the hypothesis that the negativity bias in affective processing occurs as early as the initial categorization into valence classes.

Determination of tacrine and its metabolites in human plasma and urine by high-performance liquid chromatography and fluorescence detection

A new method for the simultaneous quantitation of tacrine and the three metabolites, 1-hydroxytacrine (velnacrine, maleate), 2-hydroxytacrine and 4-hydroxytacrine, in human plasma and urine has been developed. The method was based on simple one-step liquid-liquid extraction with ethyl acetate followed by isocratic, reversed-phase high-performance liquid chromatography and fluorescence detection (excitation: 330 nm and emission: 365 nm). The limit of detection in plasma was 0.5 nM for 2-hydroxytacrine and 4-hydroxytacrine, 2 nM for 1-hydroxytacrine and tacrine. In urine it was 60 nM for 2-hydroxytacrine and 4-hydroxytacrine, 30 nM for 1-hydroxytacrine and 80 nM for tacrine. The limit of quantification in plasma was 2.5 nM for 2-hydroxytacrine and 4-hydroxytacrine, 10 nM for 1-hydroxytacrine and 2 nM for tacrine. In urine it was 120 nM for all components. The overall mean recoveries ranged from 84 to 105% in plasma and from 64 to 100% in urine for all four compounds.

Utilization of glutathione (L-gamma-glutamyl-L-cysteinylglycine) by Fusobacterium nucleatum subspecies nucleatum

Although fusobacteria use amino acids and peptides as energy source, it is not known whether they are able to actively transport peptides into the cell. In the present study the tripeptide glutathione was used as a model substance to investigate peptide uptake in Fusobacterium nucleatum subsp. nucleatum. Cells harvested after 2 days of growth on blood agar or in their exponential growth phase in broth were suspended in buffer with glutathione, L-cysteinylglycine and L-cysteine. As a measure of cell uptake, the formation of hydrogen sulfide was followed. Cells from blood agar had a low capacity to form hydrogen sulfide from the tripeptide glutathione and the dipeptide L-cysteinylglycine. However, hydrogen sulfide was formed from L-cysteinylglycine, but not from glutathione or from L-cysteine, by cells grown in broth in such a way that it strongly indicated an active transport of L-cysteinylglycine with a Km of 18 microM. Hydrogen sulfide was efficiently formed from glutathione by cells grown in broth in the presence 1 mM glutathione. In these cells a glycylglycine-dependent L-gamma-glutamyl peptidase activity was induced. It is probable that the efficient utilization of glutathione for hydrogen sulfide formation mirrored the uptake of L-cysteinylglycine after an L-gamma-glutamyl peptidase had split L-glutamate off from glutathione.

Peptostreptococcus micros has a uniquely high capacity to form hydrogen sulfide from glutathione

There are high amounts of hydrogen sulfide in deep periodontal pockets. This volatile sulfur compound may be formed from L-cysteine, but only low levels of this amino acid can be expected to be present in periodontal pockets. Glutathione, L-gamma-glutamyl-L-cysteinylglycine, is in high concentration in most tissue cells, and this tripeptide may be more readily available as a source of hydrogen sulfide formation in the pockets. The ability of 37 different species of oral bacteria to utilize glutathione in hydrogen sulfide formation was studied. Of these species, only 2 species of Peptostreptococcus and 5 species of Fusobacterium formed high amounts of hydrogen sulfide from glutathione within 24 h. Since the initial rate of hydrogen sulfide formation was more than 5 times higher in Peptostreptococcus micros than in any of the other bacterial species, the kinetics of sulfide formation from glutathione by P. micros was further elucidated. The formation of sulfide followed quite closely hyperbolic Michaelis-Menten kinetics. The maximal initial rate of sulfide formation (Vmax) was 163 +/- 2 nmol sulfide per minute per milligram of cellular protein. Half maximal initial rate (Km) was obtained at 7.4 +/- 0.8 microM glutathione. The initial rate of sulfide formation from L-cysteine was much slower and was almost proportional to L-cysteine concentration. This difference in kinetics of sulfide formation between glutathione and L-cysteine strongly suggested that glutathione was actively transported into the cell, whereas the transport of L-cysteine was more or less controlled by diffusion. The sulfide formation from the dipeptide L-cysteinylglycine also followed quite closely hyperbolic Michaelis-Menten kinetics.(ABSTRACT TRUNCATED AT 250 WORDS)

Four major transcriptional responses in the methionine/threonine biosynthetic pathway of Saccharomyces cerevisiae

Genes encoding enzymes in the threonine/methionine biosynthetic pathway were cloned and used to investigate their transcriptional response to signals known to affect gene expression on the basis of enzyme specific-activities. Four major responses were evident: strong repression by methionine of MET3, MET5 and MET14, as previously described for MET3, MET2 and MET25; weak repression by methionine of MET6; weak stimulation by methionine but no response to threonine was seen for THR1, HOM2 and HOM3; no response to any of the signals tested, for HOM6 and MES1. In a BOR3 mutant, THR1, HOM2 and HOM3 mRNA levels were increased slightly. The stimulation of transcription by methionine for HOM2, HOM3 and THR1 is mediated by the GCN4 gene product and hence these genes are under the general amino acid control. In addition to the strong repression by methionine, MET5 is also regulated by the general control.