Executive Control and Associated Brain Activity in Children With Familial High-Risk of Schizophrenia or Bipolar Disorder: A Danish Register-based Study

BACKGROUND AND HYPOTHESES

Impaired executive control is a potential prognostic and endophenotypic marker of schizophrenia (SZ) and bipolar disorder (BP). Assessing children with familial high-risk (FHR) of SZ or BP enables characterization of early risk markers and we hypothesize that they express impaired executive control as well as aberrant brain activation compared to population-based control (PBC) children.

STUDY DESIGN

Using a flanker task, we examined executive control together with functional magnetic resonance imaging (fMRI) in 11- to 12-year-old children with FHR of SZ (FHR-SZ) or FHR of BP (FHR-BP) and PBC children as part of a register-based, prospective cohort-study; The Danish High Risk and Resilience study-VIA 11.

STUDY RESULTS

We included 85 (44% female) FHR-SZ, 63 (52% female) FHR-BP and 98 (50% female) PBC in the analyses. Executive control effects, caused by the spatial visuomotor conflict, showed no differences between groups. Bayesian ANOVA of reaction time (RT) variability, quantified by the coefficient of variation (CVRT), revealed a group effect with similarly higher CVRT in FHR-BP and FHR-SZ compared to PBC (BF10 = 6.82). The fMRI analyses revealed no evidence for between-group differences in task-related brain activation. Post hoc analyses excluding children with psychiatric illness yielded same results.

CONCLUSION

FHR-SZ and FHR-BP at age 11-12 show intact ability to resolve a spatial visuomotor conflict and neural efficacy. The increased variability in RT may reflect difficulties in maintaining sustained attention. Since variability in RT was independent of existing psychiatric illness, it may reflect a potential endophenotypic marker of risk.

Suicidal Ideation and Non-Suicidal Self-Injury Following Early Childhood Psychotic Experiences in Preadolescent Children at Familial High Risk of Schizophrenia or Bipolar Disorder-The Danish High Risk and Resilience Study, VIA 11

BACKGROUND AND HYPOTHESIS

Suicide is a leading cause of death in youth and is often preceded by suicidal ideation (SI) and non-suicidal self-injury (NSSI). Identifying early markers of risk for SI and NSSI could improve timely identification of at-risk individuals.

STUDY DESIGN

Children (mean age 11.9, SD 0.2) at familial high risk of schizophrenia (N = 171), or bipolar disorder (N = 104), and controls (N = 174) were assessed for psychotic experiences (PE), SI, NSSI, and Axis I mental disorders in face-to-face interviews in early and middle childhood (age 7 and 11).

STUDY RESULTS

Having 2 types of early childhood PE predicted middle childhood SI after accounting for previous SI, NSSI, and mental disorders (OR 2.8, 95% CI 1.1-6.9; P = .03). Two PE predicted NSSI (OR 3.0, 95% CI 1.2-7.7; P = .02) in excess of previous SI, NSSI, mental disorders, and familial risk. Persistent and incident PE predicted SI (OR 3.2, 95% CI, 1.1-8.8; P = .03; OR 3.8, 95% CI, 1.3-11.5; P = .02) in the fully adjusted model. Nineteen percent of children with persistent PE reported middle childhood SI vs 3.8% of those who never reported PE. In children with early childhood mental disorders, those who reported 2 PE had 4.4-fold increased odds of later SI (95% CI, 1.2-16.7; P = .03) after adjustments. PE were nondifferentially associated with outcomes across familial risk groups.

CONCLUSIONS

Early childhood PE index elevated risk for subsequent SI and NSSI beyond what can be attributed to presence of mental disorders. Mental health screenings and clinical assessments should include early childhood PE.

Pubertal timing, sex hormone levels, and associations between early life adversity and accelerated development amongst 11-year-old children of parents with schizophrenia or bipolar disorder and controls: The Danish high risk and Resilience study via 11

Background

Children of parents with severe mental illness have several known risk factors for altered pubertal timing. Pubertal timing is important for children's physical and emotional development. We aimed to examine pubertal timing and associations between pubertal timing, early life adversity and child problem behavior including psychiatric diagnoses among children of parents with schizophrenia or bipolar disorder and controls.

Methods

Self-reported Tanner stage (mean age 11.9, range 10.87-12.67), sex hormone levels, home environment, placement out of home, and problem behavior including psychiatric diagnoses of children at familial high-risk (FHR) of schizophrenia (FHR-SZ), bipolar disorder (FHR-BP) and population-based controls (PBC) were assessed.

Results

A total of 465 children participated in the study (Tanner assessment N = 417, sex hormones N = 293). Assessed with self-reported Tanner, no difference in pubertal timing was found between groups (p = 0.09). Hormone levels did not differ between groups except for inhibin B (mean (SD) = 55.86 (29.13) pg/mL for FHR-SZ girls vs 84.98 (47.98) pg/mL) for PBC girls (p < 0.001)) and for follicle stimulating hormone (FSH) (mean (SD) = 5.82 (1.45) U/L for FHR-BP girls vs 4.54 (1.68) U/L for PBC girls (p < 0.001)). FHR children who were placed out of home (17 children, 3.8% of participants) had higher Tanner stages than those living at home (p < 0.001). Timing was not associated with level of problem behavior or psychiatric diagnoses.

Conclusions

FHR children did not differ from controls in pubertal timing. Early life adversity assessed as placement out of home may be associated with accelerated pubertal timing among children of parents with schizophrenia or bipolar disorder.

Development of social functioning in preadolescent children at familial high-risk of schizophrenia or bipolar disorder - a 4-year follow-up study from age 7 to 11

Social functioning is a major indicator of psychosis risk and evidence is lacking regarding social functioning development during preadolescence in children at familial high risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP). We aimed to investigate development of social functioning from age 7 to 11 in children at FHR-SZ or FHR-BP compared with population-based controls. At 4-year follow-up, 179 children at FHR-SZ (mean age 12.0 y, SD 0.3), 105 children at FHR-BP (mean age 11.9 y, SD 0.2), and 181 controls (mean age 11.9 y, SD 0.2) participated. We used the Vineland-II to measure social functioning. Development of social functioning was non-significantly different across groups on the Socialization Composite score as well as the subscales Interpersonal Relations, Play and Leisure, and Coping Skills. At 4-year follow-up, children at FHR-SZ demonstrated impaired social functioning, whereas children at FHR-BP displayed social functioning comparable to controls except from impaired coping skills. From age 7 to 11, the maturational pace of social functioning in children at FHR-SZ and FHR-BP is parallel to that of controls. Children at FHR-SZ show stable social functioning deficits, whereas children at FHR-BP show normal social functioning except from emergence of discretely impaired coping skills at age 11.

A study of the genetic architecture of social responsiveness in families with parental schizophrenia or bipolar disorder and population-based controls

Twin-studies of social responsiveness have reported moderate to high heritabilities, but studies using parent-child data are lacking. Additionally, social impairments have been suggested as a vulnerability marker for schizophrenia and bipolar disorder, but the heritability of social responsiveness in this context is unknown. This study is part of the Danish High Risk and Resilience Study - VIA, comprising families with one parent with schizophrenia (n = 202) or bipolar disorder (n = 120) and population-based controls (PBC, n = 200). Social responsiveness was assessed with The Social Responsiveness Scale, Second Edition (SRS-2). Heritability was estimated from variance components, and a polygenic risk score (PRS) for autism spectrum disorder (ASD) was calculated to assess the genetic relationship between ASD and SRS-2. SRS-2 heritability was moderate to high and significantly different from zero in all groups when the children were rated by the primary caregiver. With teacher ratings, the heritability was lower and only significant in the full cohort and PBC. We found no significant association between SRS-2 and PRS for ASD. Our study confirms that social responsiveness is heritable, but that heritability estimates are affected by the child-respondent relation and familial risk of mental illness. This has implications for clinical practice and research using SRS-2 and provides insight on the familial transmission of mental illness.

Early Childhood Neurocognition in Relation to Middle Childhood Psychotic Experiences in Children at Familial High Risk of Schizophrenia or Bipolar Disorder and Population-Based Controls: The Danish High Risk and Resilience Study

BACKGROUND AND HYPOTHESIS

Familial high-risk (FHR) studies examining longitudinal associations between neurocognition and psychotic experiences are currently lacking. We hypothesized neurocognitive impairments at age 7 to be associated with increased risk of psychotic experiences from age 7 to 11 in children at familial high risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) and population-based controls (PBC), and further, impaired functioning in some neurocognitive functions to be associated with greater risk of psychotic experiences in children at FHR-SZ or FHR-BP relative to PBC.

STUDY DESIGN

Neurocognition was assessed at age 7 (early childhood) and psychotic experiences from age 7 to 11 (middle childhood) in 449 children from the Danish High Risk and Resilience Study. The neurocognitive assessment covered intelligence, processing speed, attention, visuospatial and verbal memory, working memory, and set-shifting. Psychotic experiences were assessed through face-to-face interviews with the primary caregiver and the child.

STUDY RESULTS

Set-shifting impairments at age 7 were associated with greater risk of psychotic experiences from age 7 to 11 in children at FHR-SZ. Children at FHR-BP and PBC showed no differential associations. Working memory and visuospatial memory impairments were related to increased risk of psychotic experiences across the cohort. However, adjusting for concurrent psychopathology attenuated these findings.

CONCLUSIONS

Early childhood neurocognitive impairments are risk markers of middle childhood psychotic experiences, of which impaired set-shifting appears to further increase the risk of psychotic experiences in children at FHR-SZ. More research is needed to examine longitudinal associations between neurocognitive impairments and psychotic experiences in FHR samples.

Social responsiveness in families with parental schizophrenia or bipolar disorder-The Danish High Risk and Resilience Study

Schizophrenia and bipolar disorder are highly heritable severe mental disorders associated with social impairments. Moreover, partners to individuals with one of these disorders display poorer functioning and more psychopathology, but their social skills and the transgenerational transmission remains uninvestigated. Therefore, we aimed to examine social responsiveness in families with parental schizophrenia or bipolar disorder. The cohort consists of 11-year-old children with at least one parent with schizophrenia (n = 179) or bipolar disorder (n = 105) and population-based controls (PBC, n = 181). Children and parents were assessed with The Social Responsiveness Scale, Second Edition. Duration of time each parent and child have lived together was ascertained through interviews. Parents with schizophrenia and parents with bipolar disorder exhibited poorer social responsiveness compared with PBC parents. Parents with schizophrenia displayed poorer social responsiveness compared with parents with bipolar disorder. Schizophrenia co-parents exhibited poorer social responsiveness compared with bipolar co-parents and PBC co-parents. We found significant positive associations between parents' and children's social responsiveness, with no interaction effect of duration of time living together. Considering that social impairments are suggested as a vulnerability marker, this knowledge calls for increased attention towards vulnerable families, particularly those where both parents have social impairments.

Affective lability in parents with schizophrenia or bipolar disorder and their co-parents - The Danish High Risk and Resilience Study VIA 7

In bipolar disorder, dysregulation of affect is a core feature while knowledge on affective lability in schizophrenia is sparse. Research on affective lability in partners to individuals with schizophrenia or bipolar disorder is also lacking. The objective of this study was to investigate affective lability in parents with schizophrenia or bipolar disorder, and their co-parents without these disorders. The Danish High Risk and Resilience Study - VIA 7 is a population-based cohort study. This study focuses on parents diagnosed with schizophrenia (n = 148), their co-parents (n = 157), parents with bipolar disorder (n = 98), their co-parents (n = 89) and control parents (n = 359). The Affective Lability Scale - short form (ALS-SF) was used to measure affective lability. We found significantly higher levels of affective lability in parents with schizophrenia and bipolar disorder compared with controls, but no significant differences between bipolar disorder and schizophrenia. Co-parents to parents with schizophrenia had significantly higher levels of affective lability compared to controls. Our results add to the existing knowledge concerning underlying transdiagnostic factors and nonrandom mating in schizophrenia and bipolar disorder and highlight the need for studies of parental affective lability as a potential risk factor for offspring in families with parental schizophrenia or bipolar disorder.

Neurocognitive Subgroups in Children at Familial High-risk of Schizophrenia or Bipolar disorder: Subgroup Membership Stability or Change From Age 7 to 11-The Danish High Risk and Resilience Study

BACKGROUND AND HYPOTHESIS

Subgroups with distinct levels of neurocognitive functioning exist in children of parents with schizophrenia or bipolar disorder. However, studies investigating the temporal stability of subgroup membership are currently lacking. We hypothesized that a minority of children at familial high-risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) would transition to a different neurocognitive subgroup from age 7 to 11 and that most transitions would be to a more impaired subgroup.

STUDY DESIGN

Latent profile analysis was used to identify subgroups at two assessments (age 7 and 11) based on the performance of 320 children at FHR-SZ or FHR-BP across eight neurocognitive functions. Temporal stability in subgroup membership was evaluated with latent profile transition analysis. Population-based controls (age 7, n = 199; age 11, n = 178) were included as a reference group. Children transitioning to a more impaired subgroup were compared with nontransitioning children on sex, FHR-status, global functioning, and psychopathology.

STUDY RESULTS

At both assessment points, we identified three subgroups based on neurocognitive performance: a moderately-severely impaired, a mildly impaired, and an above-average subgroup. A total of 12.8% of children transitioned to a different subgroup, of which the majority (85.2%) moved to a more impaired subgroup. Parental diagnosis of schizophrenia, but neither parental diagnosis of bipolar disorder, global functioning at age 7, psychopathology, nor sex significantly differentiated children transitioning to a more impaired subgroup from nontransitioning children.

CONCLUSIONS

During pre-adolescence, neurocognitive developmental lag is associated with being at FHR-SZ. Close attention to these children's neurocognitive development is indicated.

Developmental Pathways and Clinical Outcomes of Early Childhood Psychotic Experiences in Preadolescent Children at Familial High Risk of Schizophrenia or Bipolar Disorder: A Prospective, Longitudinal Cohort Study - The Danish High Risk and Resilience Study, VIA 11

OBJECTIVE

Psychotic experiences are common in children and adolescents and are associated with concurrent and subsequent psychopathology. Most findings originate from general population studies, whereas little is known of the clinical outcomes of psychotic experiences in children and adolescents at familial high risk of psychosis. We examined the prevalence of psychotic experiences in middle childhood and whether early childhood psychotic experiences and developmental pathways of psychotic experiences predicted mental disorders in middle childhood in children at familial high risk of schizophrenia (FHR-SZ), bipolar disorder (FHR-BP), and a population-based control group.

METHODS

In a longitudinal population-based cohort study children at FHR-SZ (N=170), FHR-BP (N=103), and the control group (N=174) were assessed for psychotic experiences and axis I disorders with face-to-face interviews in early and middle childhood (at 7 and 11 years of age).

RESULTS

Psychotic experiences were more prevalent in children at FHR-SZ (31.8%, odds ratio 2.1, 95% CI 1.3-3.4) than in the control group (18.4%) in middle childhood. Early childhood psychotic experiences predicted mental disorders in middle childhood after adjusting for early childhood disorders and familial risk (odds ratio 2.0, 95% CI 1.2-3.1). Having three or more psychotic experiences increased odds the most (odds ratio 2.5, 95% CI 1.1-5.7). Persistent psychotic experiences were associated with increased odds of middle childhood disorders (odds ratio 4.1, 95% CI 2.1-8.4). Psychotic experiences were nondifferentially associated with mental disorders across the three familial risk groups.

CONCLUSIONS

Early childhood psychotic experiences predict mental disorders in middle childhood. Psychotic experiences index vulnerability for psychopathology nondifferentially in children at familial high risk and the control group. Psychotic experiences should be included in mental health screenings including children at familial high risk.

Emotion regulation in 7-year-old children with familial high risk for schizophrenia or bipolar disorder compared to controls - The Danish High Risk and Resilience Study - VIA 7, a population-based cohort study

OBJECTIVES

Emotion regulation is a predictor of overall life outcome. Problems of emotion regulation are associated with multiple psychiatric disorders and could be a potential treatment target for improving well-being and functioning. Children at familial high risk of severe mental illness have a markedly increased risk of various psychopathology and constitute a group at significant risk of emotion regulation problems. Investigations of emotion regulation in children at familial high risk of severe mental illness are sparse.

METHODS

We applied an instrument for assessing emotion regulation, the Tangram Emotion Coding Manual (TEC-M), to a population-based cohort of 522 7-year-old children born to parents diagnosed with either schizophrenia or bipolar disorder and matched controls. The TEC-M is an ecologically valid, clinician-rated observational test measure of spontaneous emotion regulation. We aimed to compare emotion regulation between risk groups and to investigate associations between emotion regulation and psychopathology and daily life functioning, and between emotion regulation and an acknowledged questionnaire-based dysregulation profile.

RESULTS

In this early developmental phase, we found no between group differences in emotion regulation. We found a significant but weak negative association between emotion regulation and both child psychopathology and the presence of a dysregulation profile on the Child Behavior Checklist and a weak positive association between emotion regulation and current level of functioning.

CONCLUSIONS

These findings contribute to the understanding of emotion regulation in familial high-risk children and further studies of emotion regulation in children at familial high risk of severe mental illness are warranted.

Genetic assortative mating for schizophrenia and bipolar disorder

BACKGROUND

Psychiatric disorders are highly polygenic and show patterns of partner resemblance. Partner resemblance has direct population-level genetic implications if it is caused by assortative mating, but not if it is caused by convergence or social homogamy. Using genetics may help distinguish these different mechanisms. Here, we investigated whether partner resemblance for schizophrenia and bipolar disorder is influenced by assortative mating using polygenic risk scores (PRSs).

METHODS

PRSs from The Danish High-Risk and Resilience Study-VIA 7 were compared between parents in three subsamples: population-based control parent pairs (N=198), parent pairs where at least one parent had schizophrenia (N=193), and parent pairs where at least one parent had bipolar disorder (N=115).

RESULTS

The PRS for schizophrenia was predictive of schizophrenia in the full sample and showed a significant correlation between parent pairs (r=0.121, p=0.0440), indicative of assortative mating. The PRS for bipolar disorder was also correlated between parent pairs (r=0.162, p=0.0067), but it was not predictive of bipolar disorder in the full sample, limiting the interpretation.

CONCLUSIONS

Our study provides genetic evidence for assortative mating for schizophrenia, with important implications for our understanding of the genetics of schizophrenia.

Neurocognitive Development in Children at Familial High Risk of Schizophrenia or Bipolar Disorder

IMPORTANCE

Neurocognitive impairments exist in children at familial high risk (FHR) of schizophrenia and bipolar disorder. Studies on preadolescent developmental courses of neurocognition are important to describe shared and distinct neurodevelopmental pathways in these groups.

OBJECTIVE

To assess the development in specific neurocognitive functions from age 7 to 11 years in children at FHR of schizophrenia or bipolar disorder compared with children in a population-based control (PBC) group.

DESIGN, SETTING, AND PARTICIPANTS

The Danish High Risk and Resilience Study is a prospective, longitudinal, cohort study that collected data from January 1, 2013, to January 31, 2016 (phase 1), and from March 1, 2017, to June 30, 2020 (phase 2). Data were collected at 2 university hospitals in Denmark, and participants included 520 children at FHR of schizophrenia or bipolar disorder along with a PBC group matched with the group of children at FHR of schizophrenia by age, sex, and municipality.

EXPOSURES

Parental schizophrenia, bipolar disorder, or neither.

MAIN OUTCOMES AND MEASURES

Neurocognitive functioning was assessed with validated tests of intelligence, processing speed, attention, memory, verbal fluency, and executive functioning. Multilevel mixed-effects linear regression models with maximum likelihood estimation were used to estimate neurocognitive development from age 7 to 11 years.

RESULTS

At 4-year follow-up, a total of 451 children (mean [SD] age; 11.9 [0.2] years; 208 girls [46.1%]) underwent neurocognitive testing. There were a total of 170 children at FHR of schizophrenia (mean [SD] age, 12.0 [0.3]; 81 girls [47.7%]), 103 children at FHR of bipolar disorder (mean [SD] age, 11.9 [0.2] years; 45 girls [43.7%]), and 178 children in the PBC group (mean [SD] age, 11.9 [0.2] years; 82 girls [46.1%]). At either age 7 or 11 years or at both assessments, 520 children participated in the neurocognitive assessment and were therefore included in the analyses. When correcting for multiple comparisons, no statistically significant time × group interactions were observed across the 3 groups. Compared with the PBC group at 4-year follow-up, children at FHR of schizophrenia showed significant neurocognitive impairment in 7 of 24 neurocognitive measures (29.2%; Cohen d range, 0.29-0.37). Compared with children at FHR of bipolar disorder, children at FHR of schizophrenia had significant neurocognitive impairment in 5 of 24 measures (20.8%; Cohen d range, 0.29-0.38). Children at FHR of bipolar disorder and those in the PBC group did not differ significantly.

CONCLUSIONS AND RELEVANCE

In this cohort study, findings suggest that neurocognitive maturation was comparable across groups of children at FHR of schizophrenia or bipolar disorder compared with PBCs from age 7 to 11 years. Compared with the PBC group, children at FHR of schizophrenia demonstrated widespread, stable, neurocognitive impairments during this period, whereas children at FHR of bipolar disorder showed no neurocognitive impairments, which may indicate distinct neurodevelopmental pathways in children at FHR of schizophrenia and bipolar disorder.

Neurocognitive heterogeneity in 7-year-old children at familial high risk of schizophrenia or bipolar disorder: The Danish high risk and resilience study - VIA 7

BACKGROUND

Studies of neurocognitive heterogeneity in young children at familial high-risk of bipolar disorder (FHR-BP) or schizophrenia (FHR-SZ) are important to investigate inter-individual neurocognitive differences. We aimed to identify neurocognitive subgroups, describe prevalence of FHR-BP or FHR-SZ children herein, and examine risk ratios (RR) compared with controls.

METHODS

In a population-based cohort of 514 7-year-old children (197 FHR-SZ, 118 FHR-BP, and 199 matched controls) we used hierarchical cluster analyses to identify subgroups across 14 neurocognitive indices.

RESULTS

Three neurocognitive subgroups were derived: A Mildly Impaired (30%), Typical (51%), and Above Average subgroup (19%). The Mildly Impaired subgroup significantly underperformed controls (Cohen d = 0.11-1.45; Ps < 0.001) except in set-shifting (P = .84). FHR-SZ children were significantly more prevalent in the Mildly Impaired subgroup; FHR-BP children were more so in the Above Average subgroup (X² (2, N = 315) = 9.64, P < .01). 79.7% FHR-BP and 64.6% FHR-SZ children demonstrated typical or above average neurocognitive functions. Neurocognitive heterogeneity related significantly to concurrent functioning, psychopathology severity, home environment adequacy, and polygenic scores for schizophrenia (Ps <. 01). Compared with controls, FHR-SZ and FHR-BP children had a 93% (RR, 1.93; 95% CI, 1.40-2.64) and 8% (RR, 1.08; 95% CI, 0.71-1.66) increased risk of Mildly Impaired subgroup membership.

LIMITATIONS

Limitations include the cross-sectional design and smaller FHR-BP sample size.

CONCLUSIONS

Identification of neurocognitive heterogeneity in preadolescent children at FHR-BP or FHR-SZ may ease stigma and enable pre-emptive interventions to enhance neurocognitive functioning and resilience to mental illness in the impaired sub-population.

Exploring protective and risk factors in the home environment in high-risk families - results from the Danish High Risk and Resilience Study-VIA 7

BACKGROUND

Exposure to inadequate home environment may put the healthy development of familial high-risk children at risk. This study aimed to investigate associations between risk factors and an adequate home environment of children having a parent diagnosed with schizophrenia or bipolar disorder.

METHODS

From a cohort of 522 children, data from 463 7-year-old children was included. Of these 172 children had familial risk for schizophrenia, 109 children had familial risk for bipolar disorder, and 190 were population-based controls. As part of a comprehensive battery, all participants were assessed with the Middle Childhood-Home Observation for Measurement of the Environment Inventory (MC-HOME Inventory) measuring the quality of the home environment.

RESULTS

When analyzing all families together, we found that having a parent diagnosed with schizophrenia would have a negative impact on the home environment (ß = -1.08; 95% CI (-2.16;-0.01); p = 0.05), while familial risk for bipolar disorder did not show significant predictive value. Being a single caregiver and child having experienced severe life events from ages 4 to 7 showed significant negative impact, while child having a mental illness diagnosis did not. Being a female caregiver, good social functioning of the caregiver, high child IQ and not being a single caregiver were found to predict positive values for the home environment. We found similar results when analyzing caregivers with and without a diagnosis separately.

CONCLUSIONS

Knowledge of what predicts good home environment should be used to inform development of early interventions for families at risk.

The Danish High-Risk and Resilience Study-VIA 15 - A Study Protocol for the Third Clinical Assessment of a Cohort of 522 Children Born to Parents Diagnosed With Schizophrenia or Bipolar Disorder and Population-Based Controls

BACKGROUND

Children born to parents with severe mental illness have gained more attention during the last decades because of increasing evidence documenting that these children constitute a population with an increased risk of developing mental illness and other negative life outcomes. Because of high-quality research with cohorts of offspring with familial risk and increased knowledge about gene-environment interactions, early interventions and preventive strategies are now being developed all over the world. Adolescence is a period characterized by massive changes, both in terms of physical, neurologic, psychological, social, and behavioral aspects. It is also the period of life with the highest risk of experiencing onset of a mental disorder. Therefore, investigating the impact of various risk and resilience factors in adolescence is important.

METHODS

The Danish High-Risk and Resilience Study started data collection in 2012, where 522 7-year-old children were enrolled in the first wave of the study, the VIA 7 study. The cohort was identified through Danish registers based on diagnoses of the parents. A total of 202 children had a parent diagnosed with schizophrenia, 120 children had a parent diagnosed with bipolar disorder, and 200 children had parents without these diagnoses. At age 11 years, all children were assessed for the second time in the VIA 11 study, with a follow-up retention rate of 89%. A comprehensive assessment battery covering domains of psychopathology, neurocognition, social cognition and behavior, motor development and physical health, genetic analyses, attachment, stress, parental functioning, and home environment was carried out at each wave. Magnetic resonance imaging scans of the brain and electroencephalograms were included from age 11 years. This study protocol describes the third wave of assessment, the VIA 15 study, participants being 15 years of age and the full, 3-day-long assessment battery this time including also risk behavior, magnetoencephalography, sleep, and a white noise paradigm. Data collection started on May 1, 2021.

DISCUSSION

We will discuss the importance of longitudinal studies and cross-sectional data collection and how studies like this may inform us about unmet needs and windows of opportunity for future preventive interventions, early illness identification, and treatment in the future.

Executive functions in 7-year-old children of parents with schizophrenia or bipolar disorder compared with controls: The Danish High Risk and Resilience Study-VIA 7, a population-based cohort study

Cognitive impairments are strongly associated with schizophrenia (SZ) and bipolar disorder (BP) with executive functions (EF) impairments as a likely key feature. Studies of everyday behavior rated EF in young children at familial high risk of SZ (FHR-SZ) are scarce and, to our knowledge, non-existent in young children at familial high risk of BP (FHR-BP). We aimed to compare everyday behavior-rated EF of FHR-SZ, FHR-BP, and control children. A nationwide population-based cohort of 522 7-year-old children with parents diagnosed with either SZ (N = 202) or BP (N = 120) and matched controls (N = 200) were recruited using the Danish national registries. The children's EF were assessed with the Behavior Rating Inventory of Executive Functions questionnaire rated by primary caregivers and teachers. According to primary caregiver assessments, FHR-SZ children displayed widespread EF impairments and had an odds ratio of 3.7 (2.0-6.9) of having clinically significant global EF impairments compared to controls. FHR-BP children were most severely impaired regarding EF related to emotional control and had an odds ratio of 2.5 (1.2-5.1) of clinically significant global EF impairments compared to controls. Teacher assessments were overall comparable to primary caregiver assessments but teachers rated more difficulties in the FHR-SZ group than primary caregivers. Already at age 7, children with a parental history of SZ or BP displayed significant impairments of EF in everyday-life situations. FHR-SZ children displayed widespread significant impairments of EF, whereas FHR-BP children were most severely impaired on emotional control. Clinicians should be aware of potential EF impairments in FHR children.

A Nationwide Cohort Study of Nonrandom Mating in Schizophrenia and Bipolar Disorder

Nonrandom mating in parents with schizophrenia or bipolar disorder increases the population-level genetic variance among the offspring generation and creates familial (risk) environments likely to be shaped by specific conditions. The objective of this study was to investigate the occurrence of mental disorder and levels of cognitive and social functioning in individuals who have children by partners with schizophrenia or bipolar disorder compared to controls. The Danish High Risk and Resilience Study VIA 7 is a population-based cohort study conducted in Denmark between 2013 and 2016. This study focus on parents diagnosed with schizophrenia (n = 150) or bipolar disorder (n = 100) and control parents (n = 182), as well as their partners without schizophrenia or bipolar disorder (n = 440). We used linear mixed-effect models, and main outcomes were mental disorders, intelligence, processing speed, verbal working memory, and social functioning. We found that parents having children by a partner with schizophrenia or bipolar disorder more often fulfilled the criteria for a mental disorder and had poorer social functioning compared to parents having children by a partner without schizophrenia or bipolar disorder. Furthermore, parents having children by a partner with schizophrenia performed poorer on processing speed compared to parents in the control group. The presence of nonrandom mating found in this study has implications for our understanding of familial transmission of these disorders and our findings should be considered in future investigations of potential risk factors for children with a parent with schizophrenia or bipolar disorder.

Decision making and its associations to neurocognitive functions, psychopathology, and the home environment in seven-year-old children at familial high risk of schizophrenia or bipolar disorder: The Danish High Risk and Resilience Study VIA 7

BACKGROUND

Slower and suboptimal decision making has been identified in adults with schizophrenia and bipolar disorder. Owing to the limited evidence on decision making in first-degree relatives, we aimed to investigate, whether alterations in decision making are present in young children at familial high risk of bipolar disorder or schizophrenia.

METHODS

In this population-based cohort study we assessed decision making in 197 children at familial high risk of schizophrenia (FHR-SZ), 115 children at familial high risk of bipolar disorder (FHR-BP), and 190 controls aged seven using the Cambridge Gambling Task. Potential associations to neurocognition, psychopathology, and the home environment were investigated.

RESULTS

Children at FHR-SZ or FHR-BP displayed intact decision making. Quality of decision making showed significant but weak cross-sectional associations to neurocognition and adequacy of the home environment. Associations to aspects of executive functions and the home environment differed across groups.

LIMITATIONS

Due to the cross-sectional nature of this study, the predictive value of efficient and inefficient decision making remains to be investigated in planned follow-up studies of this cohort.

CONCLUSIONS

Young children at FHR-SZ or FHR-BP do not differ from controls in decision making efficacy, which does not appear to be an early risk marker of bipolar disorder or schizophrenia. Decision making is weakly associated to neurocognition and the home environment, but not to general intelligence or psychopathology.

Visual attention in 7-year-old children at familial high risk of schizophrenia or bipolar disorder: The Danish high risk and resilience study VIA 7

BACKGROUND

Attention deficits are found in children at familial high risk of schizophrenia (FHR-SZ) and bipolar disorder (FHR-BP) using assessment methods relying on motor-based response latency. This study compares visual attention functions in children at FHR-SZ or FHR-BP with controls using an unspeeded task unconfounded by motor components.

METHODS

Visual attention was assessed in 133 7-year-old children at FHR-SZ (N = 56) or FHR-BP (N = 32), and controls (N = 45) using the unspeeded paradigm, TVA-based whole report. We compared four parameters of visual attention: visual processing speed, visual short-term memory, threshold for visual perception, and error rate. Further, we investigated their potential relationships with severity of psychopathology, adequacy of the home environment, and neurocognitive measures.

RESULTS

Children at FHR-SZ displayed significant deficits in perceptual processing speed of visual attention compared with controls (p < .001; d = 0.75) as did children at FHR-BP (p < .05; d = 0.54). Visual processing speed was significantly associated with spatial working memory (β = -0.23; t(68) = -3.34, p = .01) and psychomotor processing speed (β = 0.14, t(67) = 2.11, p < .05).

LIMITATIONS

Larger group sizes would have permitted inclusion of more predictors in the search for neurocognitive and other factors associated with the parameters of TVA-based whole report.

CONCLUSIONS

Young children at FHR-SZ and FHR-BP display significant deficits in processing speed of visual attention, which may reflect the effect of shared vulnerability risk genes. Early identification of children at FHR-SZ and FHR-BP with perceptual processing speed impairments may represent a low-cost basis for low-risk interventions.

Home visits in the Danish High Risk and Resilience Study - VIA 7: assessment of the home environment of 508 7-year-old children born to parents diagnosed with schizophrenia or bipolar disorder

OBJECTIVE

The home environment provided by the caregivers of a child is an influential single factor for development and well-being. We aimed to compare the quality of the home environment of children at familial high risk of schizophrenia or bipolar disorder with population-based controls.

METHODS

Danish nationwide registers were used to retrieve a cohort of 522 7-year-old children of parents diagnosed with schizophrenia (N = 202), bipolar disorder (N = 120) or none of these diagnoses (N = 200). The home environment was assessed using the Middle Childhood-Home Observation for Measurement of the Environment Inventory (MC-HOME Inventory).

RESULTS

The proportion of children living in home environments that were evaluated not to meet the needs of a 7-year-old child was significantly larger in the two familial high-risk groups. This was true for 21% of the children with familial predisposition for schizophrenia and 7% of children with familial disposition for bipolar disorder.

CONCLUSION

Children born to parents diagnosed with schizophrenia and to a lesser extent bipolar disorder are at an increased risk of growing up in a home environment with an insufficient level of stimulation and support. Identifying families with inadequate home environments is a necessary step towards specialized help and support to at-risk families.

Exploring Comorbidity Within Mental Disorders Among a Danish National Population

IMPORTANCE

Individuals with mental disorders often develop comorbidity over time. Past studies of comorbidity have often restricted analyses to a subset of disorders and few studies have provided absolute risks of later comorbidity.

OBJECTIVES

To undertake a comprehensive study of comorbidity within mental disorders, by providing temporally ordered age- and sex-specific pairwise estimates between the major groups of mental disorders, and to develop an interactive website to visualize all results and guide future research and clinical practice.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study included all individuals born in Denmark between January 1, 1900, and December 31, 2015, and living in the country between January 1, 2000, and December 31, 2016. The analyses were conducted between June 2017 and May 2018.

MAIN OUTCOMES AND MEASURES

Danish health registers were used to identify mental disorders, which were examined within the broad 10-level International Statistical Classification of Diseases and Related Health Problems, 10th Revision, subchapter groups (eg, codes F00-F09 and F10-F19). For each temporally ordered pair of disorders, overall and lagged hazard ratios and 95% CIs were calculated using Cox proportional hazards regression models. Absolute risks were estimated using competing risks survival analyses. Estimates for each sex were generated.

RESULTS

A total of 5 940 778 persons were included in this study (2 958 293 men and 2 982 485 women; mean [SD] age at beginning of follow-up, 32.1 [25.4] years). They were followed up for 83.9 million person-years. All mental disorders were associated with an increased risk of all other mental disorders when adjusting for sex, age, and calendar time (hazard ratios ranging from 2.0 [95% CI, 1.7-2.4] for prior intellectual disabilities and later eating disorders to 48.6 [95% CI, 46.6-50.7] for prior developmental disorders and later intellectual disabilities). The hazard ratios were temporally patterned, with higher estimates during the first year after the onset of the first disorder, but with persistently elevated rates during the entire observation period. Some disorders were associated with substantial absolute risks of developing specific later disorders (eg, 30.6% [95% CI, 29.3%-32.0%] of men and 38.4% [95% CI, 37.5%-39.4%] of women with a diagnosis of mood disorders before age 20 years developed neurotic disorders within the following 5 years).

CONCLUSIONS AND RELEVANCE

Comorbidity within mental disorders is pervasive, and the risk persists over time. This study provides disorder-, sex-, and age-specific relative and absolute risks of the comorbidity of mental disorders. Web-based interactive data visualization tools are provided for clinical utility.

Assessment of Neurocognitive Functions in 7-Year-Old Children at Familial High Risk for Schizophrenia or Bipolar Disorder: The Danish High Risk and Resilience Study VIA 7

IMPORTANCE

Children at familial high risk of schizophrenia spectrum disorders (FHR-SZ) or bipolar disorder (FHR-BP) exhibit neurocognitive impairments. Large studies of neurocognition in young children at familial high risk at the same age are important to differentiate the pathophysiology and developmental trajectory of these 2 groups.

OBJECTIVE

To characterize neurocognitive functions in 7-year-old children with FHR-SZ or FHR-BP and a control population.

DESIGN, SETTING, AND PARTICIPANTS

This multisite population-based cohort study collected data from January 1, 2013, to January 31, 2016, in the first wave of the Danish High Risk and Resilience Study VIA 7 at 2 university hospital research sites in Copenhagen and Aarhus using Danish registries. Participants (n = 514) included 197 children with FHR-SZ, 118 with FHR-BP, and 199 controls matched with the FHR-SZ group for age, sex, and municipality. Assessors were blinded to risk status.

EXPOSURES

Parents with schizophrenia, bipolar disorder, or neither diagnosis.

MAIN OUTCOMES AND MEASURES

Neurocognitive functions were measured across 23 tests. Four neurocognitive domains were derived by principal component analysis, including processing speed and working memory, verbal functions, executive and visuospatial functions, and declarative memory and attention.

RESULTS

A total of 514 children aged 7 years were included in the analysis (46.3% girls), consisting of 197 children with FHR-SZ (46.2% girls), 118 with FHR-BP (46.6% girls), and 199 controls (46.2% girls). Children with FHR-SZ were significantly impaired compared with controls on processing speed and working memory (Cohen d = 0.50; P < .001), executive and visuospatial functions (Cohen d = 0.28; P = .03), and declarative memory and attention (Cohen d = 0.29; P = .02). Compared with children with FHR-BP, children with FHR-SZ performed significantly poorer in processing speed and working memory (Cohen d = 0.40; P = .002), executive and visuospatial functions (Cohen d = 0.35; P = .008), and declarative memory and attention (Cohen d = 0.31; P = .03). Children with FHR-BP and controls did not differ.

CONCLUSIONS AND RELEVANCE

Children with FHR-SZ had widespread neurocognitive impairments, supporting the hypothesis of neurocognitive functions as endophenotypes of schizophrenia. The absence of neurocognitive deficits in children with FHR-BP suggests distinct neurodevelopmental manifestations in these familial high-risk groups at this age. Early detection of children with FHR-SZ and cognitive impairments is warranted to investigate associations of neurocognition with transition to psychosis, add to the knowledge of their developmental pathophysiology, and inform early intervention programs.

Hot and cold executive functions in youth with psychotic symptoms

BACKGROUND

Psychotic symptoms are common in children and adolescents and may be early manifestations of liability to severe mental illness (SMI), including schizophrenia. SMI and psychotic symptoms are associated with impairment in executive functions. However, previous studies have not differentiated between 'cold' and 'hot' executive functions. We hypothesized that the propensity for psychotic symptoms is specifically associated with impairment in 'hot' executive functions, such as decision-making in the context of uncertain rewards and losses.

METHODS

In a cohort of 156 youth (mean age 12.5, range 7-24 years) enriched for familial risk of SMI, we measured cold and hot executive functions with the spatial working memory (SWM) task (total errors) and the Cambridge Gambling Task (decision-making), respectively. We assessed psychotic symptoms using the semi-structured Kiddie Schedule for Affective Disorders and Schizophrenia interview, Structured Interview for Prodromal Syndromes, Funny Feelings, and Schizophrenia Proneness Instrument - Child and Youth version.

RESULTS

In total 69 (44.23%) youth reported psychotic symptoms on one or more assessments. Cold executive functioning, indexed with SWM errors, was not significantly related to psychotic symptoms [odds ratio (OR) 1.36, 95% confidence interval (CI) 0.85-2.17, p = 0.204). Poor hot executive functioning, indexed as decision-making score, was associated with psychotic symptoms after adjustment for age, sex and familial clustering (OR 2.37, 95% CI 1.25-4.50, p = 0.008). The association between worse hot executive functions and psychotic symptoms remained significant in sensitivity analyses controlling for general cognitive ability and cold executive functions.

CONCLUSIONS

Impaired hot executive functions may be an indicator of risk and a target for pre-emptive early interventions in youth.

The Danish High Risk and Resilience Study--VIA 7--a cohort study of 520 7-year-old children born of parents diagnosed with either schizophrenia, bipolar disorder or neither of these two mental disorders

BACKGROUND

Severe mental illnesses like schizophrenia and bipolar disorder are known to be diseases that to some extent, but not entirely can be understood genetically. The dominating hypothesis is that these disorders should be understood in a neurodevelopmental perspective where genes and environment as well as gene-environment-interactions contribute to the risk of developing the disease. We aim to analyse the influences of genetic risk and environmental factors in a population of 520 7-year-old children with either 0, 1 or 2 parents diagnosed with schizophrenia spectrum psychosis or bipolar disorder on mental health and level of functioning. We hypothesize that a larger proportion of children growing up with an ill parent will display abnormal or delayed development, behavioural problems or psychiatric symptoms compared to the healthy controls.

METHODS/DESIGN

We are establishing a cohort of 5207 year old children and both their parents for a comprehensive investigation with main outcome measures being neurocognition, behaviour, psychopathology and neuromotor development of the child. Parents and children are examined with a comprehensive battery of instruments and are asked for genetic material (saliva or blood) for genetic analyses. The participants are recruited via Danish registers to ensure representativity. Data from registers concerning social status, birth complications, somatic illnesses and hospitalization are included in the database. Psychological and relational factors like emotional climate in the family, degree of stimulation and support in the home and attachment style are also investigated.

DISCUSSION

Data collection started January 1, 2013, and is successfully ongoing. By Aug 2015 424 families are included. About 20% of the invited families decline to participate, equal for all groups.