Longitudinal, prospective evaluations of intelligence in children at risk

Neuropsychological development in the child and adolescent offspring of patients diagnosed with schizophrenia or bipolar disorder: A two-year follow-up comparative study

There has been growing scientific evidence in recent years that schizophrenia and bipolar disorder share clinical, cognitive, neuroimaging and genetic characteristics. This overlap might also be present in their offspring, who have an increased risk of developing both disorders. Comparing the characteristics of these samples may have important implications for understanding etiological processes. This study aimed to assess the development of cognitive functions over two years in a sample of child and adolescent offspring of patients diagnosed with schizophrenia (SZoff) or bipolar disorder (BDoff), comparing them with a community control group (CCoff).

METHODS

90 BDoff, 41 SZoff and 107 CCoff aged between 6 and 17 years were included at baseline. At the two-year follow-up, 84.9% of the sample was re-assessed (78 BDoff, 32 SZoff and 92 CCoff). All subjects were assessed with a comprehensive neuropsychological test battery at baseline and at the two-year follow-up to evaluate: intelligence quotient, working memory, processing speed, verbal memory and learning, visual memory, executive functions and sustained attention.

RESULTS

Processing speed, verbal memory and executive functions showed different developmental patterns among the SZoff, BDoff and CCoff groups. The SZoff group maintained baseline performances in the three variables over time, while the BDoff group presented improved processing speed and executive functioning and the CCoff group showed improvements in verbal memory and executive functions at follow-up.

CONCLUSIONS

These findings suggest that the development of some cognitive functions might differ between child and adolescent SZoff and BDoff, indicating different trajectories during neurodevelopment.

Considering the Microbiome in Stress-Related and Neurodevelopmental Trajectories to Schizophrenia

Early life adversity and prenatal stress are consistently associated with an increased risk for schizophrenia, although the exact pathogenic mechanisms linking the exposures with the disease remain elusive. Our previous view of the HPA stress axis as an elegant but simple negative feedback loop, orchestrating adaptation to stressors among the hypothalamus, pituitary, and adrenal glands, needs to be updated. Research in the last two decades shows that important bidirectional signaling between the HPA axis and intestinal mucosa modulates brain function and neurochemistry, including effects on glucocorticoid hormones and brain-derived neurotrophic factor (BDNF). The intestinal microbiome in earliest life, which is seeded by the vaginal microbiome during delivery, programs the development of the HPA axis in a critical developmental window, determining stress sensitivity and HPA function as well as immune system development. The crosstalk between the HPA and the Microbiome Gut Brain Axis (MGBA) is particularly high in the hippocampus, the most consistently disrupted neural region in persons with schizophrenia. Animal models suggest that the MGBA remains influential on behavior and physiology across developmental stages, including the perinatal window, early childhood, adolescence, and young adulthood. Understanding the role of the microbiome on critical risk related stressors may enhance or transform of understanding of the origins of schizophrenia and offer new approaches to increase resilience against stress effects for preventing and treating schizophrenia.

Altered cognitive development in the siblings of individuals with schizophrenia

The goal of the current study was to further investigate the late neurodevelopmental hypothesis of schizophrenia by examining cross-sectional, age-related changes in cognitive function among young adult: 1) siblings of individuals with schizophrenia (N = 66); (2) healthy control participants (N = 77); and (3) the siblings of healthy controls (N = 77). All subjects participated in a battery of tasks in four domains: 1) IQ; 2) working memory; 3) episodic memory; and 4) executive function. We found significant group differences in the relationships between age and performance in working memory and episodic memory, with similar patterns for executive function and verbal IQ. The siblings of individuals with schizophrenia showed impaired performance in working memory, episodic memory, and executive function. In addition, healthy controls and/or their siblings showed age-related improvements in all four cognitive domains, while the siblings of individuals with schizophrenia only showed this for verbal IQ.

Specificity of familial transmission of schizophrenia psychosis spectrum and affective psychoses in the New England family study's high-risk design

CONTEXT

There is a long history of research on the familial transmission of schizophrenia and other psychoses. However, few studies have investigated the specificity of the transmission of schizophrenia-psychosis spectrum (SPS) disorders and affective psychoses (APs) or observed high-risk offspring into mid-adulthood.

OBJECTIVES

To investigate the transmission of psychoses from parents to their offspring and the specificity of transmission across psychosis subtypes.

DESIGN

High-risk follow-up study.

SETTING

New England Family Study's High-Risk Study, with population-based community sampling from Boston, Massachusetts, and Providence, Rhode Island.

PARTICIPANTS

A total of 203 high-risk offspring of 159 parents with diagnoses of psychoses (SPS and AP) and 147 control offspring of 114 control parents.

MAIN OUTCOME MEASURES

Systematically assessed research DSM-IV psychiatric diagnoses for adult offspring.

RESULTS

Compared with those of control parents, offspring of parents with SPS had a significant, almost 6-fold elevated risk of SPS disorders and a nonsignificant doubling of risk for AP. Offspring of parents with AP had a significant 14-fold elevated risk for AP compared with offspring of controls; for SPS disorders, the risk doubled but was not significant.

CONCLUSION

Having a parent with psychosis significantly increased the risk for psychosis among offspring and demonstrated specificity for the transmission of SPS disorders and APs within families.

Premorbid cognitive deficits in young relatives of schizophrenia patients

Neurocognitive deficits in schizophrenia (SZ) are thought to be stable trait markers that predate the illness and manifest in relatives of patients. Adolescence is the age of maximum vulnerability to the onset of SZ and may be an opportune "window" to observe neurocognitive impairments close to but prior to the onset of psychosis. We reviewed the extant studies assessing neurocognitive deficits in young relatives at high risk (HR) for SZ and their relation to brain structural alterations. We also provide some additional data pertaining to the relation of these deficits to psychopathology and brain structural alterations from the Pittsburgh Risk Evaluation Program (PREP). Cognitive deficits are noted in the HR population, which are more severe in first-degree relatives compared to second-degree relatives and primarily involve psychomotor speed, memory, attention, reasoning, and social-cognition. Reduced general intelligence is also noted, although its relationship to these specific domains is underexplored. Premorbid cognitive deficits may be related to brain structural and functional abnormalities, underlining the neurobiological basis of this illness. Cognitive impairments might predict later emergence of psychopathology in at-risk subjects and may be targets of early remediation and preventive strategies. Although evidence for neurocognitive deficits in young relatives abounds, further studies on their structural underpinnings and on their candidate status as endophenotypes are needed.

Executive dysfunction in Turkish children at high risk for schizophrenia

OBJECTIVE

To explore different aspects of executive function (i.e. sequencing, set shifting and mental flexibility) in children who are at high risk for schizophrenia by comparing them with normal controls.

METHOD

The high risk (HR) group consisted of 30 children whose parents were diagnosed as schizophrenia. As the control group (CG) 30 children, whose parents did not meet any DSM IV diagnostic criteria for any psychiatric disorder, participated. They were age and sex matched with the HR group. For the evaluation of different domains of cognitive functions Wechsler intelligence scale for children-revised (WISC-R), and a group of neuropsychological tests, including Trail Making A-B Tests, Color Form Test, and Progressive Figures Test were administered. Behavioral problems were assessed using Hacettepe Adjustment Scale.

RESULTS

The subjects in the high risk group had significantly lower scores on Trail Making A-B, Color Form, Progressive Figures Tests, as well as subtests and scores of WISC-R (Information, Comprehension, Similarities, Picture Completion, Block Design, Object Assembly and Coding subtests, Verbal, Performance and Full Scale IQ scores). There is no significant difference between the two groups in the frequency and severity of behavioral problems.

CONCLUSION

Children of parents with schizophrenia displayed significantly greater number of difficulties in several areas of executive function, such as sequencing, set shifting, and mental flexibility, when compared to their controls.

Childhood developmental abnormalities in schizophrenia: evidence from high-risk studies

According to cohort studies, individuals who develop schizophrenia in adulthood show developmental abnormalities in childhood. These include delays in attainment of speech and motor milestones, problems in social adjustment, and poorer academic and cognitive performance. Another method of investigating developmental abnormalities associated with schizophrenia is the high-risk (HR) method, which follows up longitudinally the development of children at high risk for schizophrenia. Most HR studies have investigated children who have a parent with schizophrenia. This review summarizes findings concerning childhood and adolescent development from 16 HR studies and compares them with findings from cohort, conscript, and family studies. We specifically addressed two questions: (1) Does the development of HR children differ from that of control children? (2) Which developmental factors, if any, predict the development of schizophrenia-spectrum disorders in adulthood? While the answer to the first question is affirmative, there may be other mechanisms involved in addition to having a parent with schizophrenia. Factors which appear to predict schizophrenia include problems in motor and neurological development, deficits in attention and verbal short-term memory, poor social competence, positive formal thought disorder-like symptoms, higher scores on psychosis-related scales in the MMPI, and severe instability of early rearing environment.

Attention, cognition, and motor perseveration in adolescents at genetic risk for schizophrenia and control subjects

Twenty-three offspring of schizophrenic parents (mean age = 12.1 years, SD = 3.2) and 61 adolescent control subjects (mean age = 12.3 years, SD = 3.3) were compared in their performance of the following psychometric tests: simple reaction times (RTs), warned RTs in a monomodal and cross-modal design, d2 concentration test, a motor perseveration test, and a cognitive performance measure (Wechsler Intelligence Scale). The results were validated in a second analysis in which a subgroup of the control subjects were matched to the high-risk subjects for the following characteristics: age, gender, education, and environmental background. Significant deficits were found in the high-risk group in tests that required sustained attention and information processing under high perceptual load (RT measures and d2 concentration test). Deficits were particularly prominent for the processing of visual stimuli; sensory incongruence might also have been a contributor to this deficit. The attentional dysfunction of high-risk subjects might explain their tendency to show less structured behavior and distractibility as reflected by their higher entropy scores in a motor perseveration test. Cognitive evaluation showed a significant deficit in the high-risk group, primarily as reflected in the verbal IQ score.

Head-injured parents and their children. Psychosocial consequences of a traumatic syndrome

Traumatic brain injury, a prevalent health problem in contemporary society, poses complex adaptational challenges for victims' families. The sequelae most disruptive to family functioning appear to be residual psychiatric symptoms. With a peak incidence among young adults, brain trauma also befalls many parents of dependent children; these children are vulnerable to subsequent emotional and behavioral difficulties. An approach to these problems must recognize the broad spectrum of clinical outcomes from brain injury. Valuable insights may also be gained from earlier work on children's responses to more familiar parental psychiatric disorders. Three case reports of children with head-injured parents are presented, followed by a discussion of treatment considerations for this emerging "at-risk" population.

Intelligence, classroom behavior, and academic achievement in children at high and low risk for psychopathology: a structural equation analysis

The intelligence, academic achievement, and classroom behavior of 158 children were assessed in a sample that is being followed longitudinally. The sample included children at high risk for mental disorder by virtue of having a parent with a psychiatric diagnosis of schizophrenia or affective disorder, children at moderate risk, and children at low risk. A series of path analyses indicated that in this sample (1) classroom behavior was more likely an affect that a cause of academic achievement, and (2) the influence of parental psychopathology on classroom behavior was mediated by a child's intelligence and academic achievement. We were unable to substantiate an unmediated causal link between parental psychopathology and children's academic achievement or classroom behavior.