Early childhood head injury attenuates declines in impulsivity and aggression across adolescent development in twins

Head Injuries Among Children Treated in US Emergency Departments, 2015-2019

This study evaluates the epidemiology of nonfatal head injuries among children aged 1 to 4 years associated with consumer products and identifies the specific consumer products associated with these injuries. Data for children aged 1 to 4 years who presented to emergency departments (EDs) from 2015 to 2019 for a nonfatal head injury were extracted from the National Electronic Injury Surveillance System. An estimated 1 032 429 (95% confidence interval [CI]: 675 822-1 389 063) children presented to US EDs for head injuries, averaging 566 injuries daily. The average rate of head injury did not change over the 5-year study period (slope = -0.003; P = .852); it was highest among children aged 1 year (2.06 per 100 children aged 1 year), which was nearly 3 times that of children aged 4 years (rate ratio = 2.75; 95% CI: 2.73-2.77). Most injuries occurred at home (80.4%) and occurred from interacting with home furnishings (45.1%). This study underscores the need for increased head injury mitigation efforts among young children.

Executive functioning, behavior, and white matter microstructure in the chronic phase after pediatric mild traumatic brain injury: results from the adolescent brain cognitive development study

BACKGROUND

Mild traumatic brain injury (mTBI) is common in children. Long-term cognitive and behavioral outcomes as well as underlying structural brain alterations following pediatric mTBI have yet to be determined. In addition, the effect of age-at-injury on long-term outcomes is largely unknown.

METHODS

Children with a history of mTBI (n = 406; Mage = 10 years, SDage = 0.63 years) who participated in the Adolescent Brain Cognitive Development (ABCD) study were matched (1:2 ratio) with typically developing children (TDC; n = 812) and orthopedic injury (OI) controls (n = 812). Task-based executive functioning, parent-rated executive functioning and emotion-regulation, and self-reported impulsivity were assessed cross-sectionally. Regression models were used to examine the effect of mTBI on these domains. The effect of age-at-injury was assessed by comparing children with their first mTBI at either 0-3, 4-7, or 8-10 years to the respective matched TDC controls. Fractional anisotropy (FA) and mean diffusivity (MD), both MRI-based measures of white matter microstructure, were compared between children with mTBI and controls.

RESULTS

Children with a history of mTBI displayed higher parent-rated executive dysfunction, higher impulsivity, and poorer self-regulation compared to both control groups. At closer investigation, these differences to TDC were only present in one respective age-at-injury group. No alterations were found in task-based executive functioning or white matter microstructure.

CONCLUSIONS

Findings suggest that everyday executive function, impulsivity, and emotion-regulation are affected years after pediatric mTBI. Outcomes were specific to the age at which the injury occurred, suggesting that functioning is differently affected by pediatric mTBI during vulnerable periods. Groups did not differ in white matter microstructure.

The bidirectional relationship between head injuries and conduct problems: longitudinal modelling of a population-based birth cohort study

Childhood head injuries and conduct problems increase the risk of aggression and criminality and are well-known correlates. However, the direction and timing of their association and the role of their demographic risk factors remain unclear. This study investigates the bidirectional links between both from 3 to 17 years while revealing common and unique demographic risks. A total of 8,603 participants (50.2% female; 83% White ethnicity) from the Millennium Cohort Study were analysed at 6 timepoints from age 3 to 17. Conduct problems were parent-reported for ages 3 to 17 using the Strengths and Difficulties Questionnaire (SDQ) and head injuries at ages 3 to 14. A cross-lagged path model estimated the longitudinal bidirectional effects between the two whilst salient demographic risks were modelled cumulatively at three ecological levels (child, mother, and household). Conduct problems at age 5 promoted head injuries between 5 and 7 (Z = 0.07; SE = 0.03; 95% CI, 0.02-0.13), and head injuries at ages 7 to 11 promoted conduct problems at age 14 (ß = .0.06; SE = .0.03; 95% CI, 0.01-0.12). Head injuries were associated with direct child-level risk at age 3, whereas conduct problems were associated with direct risks from all ecological levels until 17 years. The findings suggest a sensitive period at 5-11 years for the bidirectional relationship shared between head injuries and conduct problems. They suggest that demographic risks for increased head injuries play an earlier role than they do for conduct problems. Both findings have implications for intervention timing.

Adolescent delinquency following co-occurring childhood head injuries and conduct problem symptoms: findings from a UK longitudinal birth cohort

Childhood conduct problems and head injuries share a bidirectional association, but how this affects the risk of adolescent delinquency is unknown. Due to their similar underlying mechanisms (i.e. increased impulsivity), this study aims to identify whether their co-occurrence increases the risk of adolescent delinquency. Data was obtained from 11,272 children at age 14 and 10,244 at age 17 years enrolled in the UK Millennium Cohort Study. Conduct problem symptoms (via the Strengths and Difficulties Questionnaire) and head injuries were parent reported from ages 3 to 14 years. Delinquency was self-reported at ages 14 and 17 including substance use, criminality, and antisocial behaviour. Incident rate ratios (IRR) were estimated for delinquency at ages 14 and 17 by childhood conduct problem and head injury status. Co-occurring head injuries and high conduct problem symptoms presented the greatest risk for overall delinquency and substance use at age 14 compared to those with the presence of one or neither (IRRs from 1.20 to 1.60). At age 17, conduct problems (with or without co-occurring head injuries) presented the greatest risk for overall delinquency, substance use, and antisocial behaviour. There was no evidence for an increased risk of delinquency at ages 14 or 17 following a head injury only. Whilst these findings suggest childhood head injuries alone do not increase the risk of adolescent delinquency, when co-occurring alongside high conduct problem symptoms there is a heightened earlier risk. These results provide further insight into adolescent delinquency and the outcomes of co-occurring childhood head injury and conduct problem symptoms.

Linked head injury and conduct problem symptom pathways from early childhood to adolescence and their associated risks: Evidence from the millennium cohort study

Conduct problems and head injuries increase the risk of delinquency and share a bidirectional association. However, how they link across development is unknown. The present study aimed to identify their linked developmental pathways and associated risk factors. Latent class analysis was modeled from Millennium Cohort Study data (n = 8,600) to identify linked pathways of conduct problem symptoms and head injuries. Head injuries were parent-reported from ages 3 to 14 and conduct problems from ages 3 to 17 using the Strengths and Difficulties Questionnaire (SDQ). Multinomial logistic regression then identified various risk factors associated with pathway membership. Four distinct pathways were identified. Most participants displayed low-level conduct problem symptoms and head injuries (n = 6,422; 74.7%). Three groups were characterized by clinically relevant levels of conduct problem symptoms and high-risk head injuries in childhood (n = 1,422; 16.5%), adolescence (n = 567; 6.6%), or persistent across development (n = 189; 2.2%). These clinically relevant pathways were associated with negative maternal parenting styles. These findings demonstrate how pathways of conduct problem symptoms are uniquely linked with distinct head injury pathways. Suggestions for general preventative intervention targets include early maternal negative parenting styles. Pathway-specific interventions are also required targeting cumulative risk at different ecological levels.

Associations between significant head injury in male juveniles in prison in Scotland UK and cognitive function, disability and crime: A cross sectional study

BACKGROUND

Although the prevalence of head injury is estimated to be high in juveniles in prison, the extent of persisting disability is unknown and relationships with offending uncertain. This limited understanding makes it difficult to develop effective management strategies and interventions to improve health or reduce recidivism. This study investigates effects of significant head injury (SHI) on cognitive function, disability and offending in juvenile prisoners, and considers relationships with common comorbidities.

METHODS

This cross-sectional study recruited male juvenile prisoners in Scotland from Her Majesty's Young Offenders Institute (HMYOI) Polmont (detaining approximately 305 of 310 male juveniles in prison in Scotland). To be included juveniles had to be 16 years or older, fluent in English, able to participate in assessment, provide informed consent and not have a severe acute disorder of cognition or communication. Head injury, cognition, disability, history of abuse, mental health and problematic substance use were assessed by interview and questionnaire.

RESULTS

We recruited 103 (34%) of 305 juvenile males in HMYOI Polmont. The sample was demographically representative of juvenile males in prisons for young offenders in Scotland. SHI was found in 82/103 (80%) and head injury repeated over long periods of time in 69/82 (85%). Disability was associated with SHI in 11/82 (13%) and was significantly associated with mental health problems, particularly anxiety. Group differences on cognitive tests were not found. However the SHI group reported poorer behavioural control on the Dysexecutive Questionnaire and were more often reported for incidents in prison than those without SHI. Characteristics of offending, including violence, did not differ between groups.

CONCLUSIONS

Although SHI is highly prevalent in juvenile prisoners, associated disability was relatively uncommon. There was no evidence for differences in cognitive test performance or offending in juveniles with and without SHI. However, signs of poorer behavioural control and greater psychological distress in juveniles with SHI suggest that they may be at greater risk of recidivism and of potentially becoming lifelong offenders. This implies a need for remedial programmes for juvenile prisoners to take account of persisting effects of SHI on mental health and self-control and education and to improve their understanding of the effects of SHI reduce the likelihood of cumulative effects from further SHI.

Reactive vs proactive aggression: A differential psychobiological profile? Conclusions derived from a systematic review

INTRODUCTION

Scholars have established subcategories of aggressive behavior in order to better understand this construct. Specifically, a classification based on motivational underpinnings makes it possible to differentiate between reactive and proactive aggression. Whereas reactive aggression is characterized by emotional lability, which means it is prone to impulsive reactions after provocation, proactive aggression is driven by low emotionality and high levels of instrumentality to obtain benefits. Some authors have conceived these two types as having a dichotomous nature, but others argue against this conceptualization, considering a complementary model more suitable. Hence, neuroscientific research might help to clarify discussions about their nature because biological markers do not present the same biases as psychological instruments.

AIM

The main objective of this study was to carry out a systematic review of studies that assess underlying biological markers (e.g., genes, brain, psychophysiological, and hormonal) of reactive and proactive aggression.

METHODS

To carry out this review, we followed PRISMA quality criteria for reviews, using five digital databases complemented by hand-searching.

RESULTS

The reading of 3993 abstracts led to the final inclusion of 157 papers that met all the inclusion criteria. The studies included allow us to conclude that heritability accounted for approximately 45% of the explained variance in both types of aggression, with 60% shared by both, especially, for overt and physical expression forms, and 10% specific to each type. Regarding allelic risk factors, whereas low functioning variants affecting serotonin transport and monoaminoxidase increased the risk of reactive aggression, high functioning variants were associated with proactive aggression. Furthermore, brain analysis revealed an overlap between the two types of aggression and alterations in the volume of the amygdala and temporal cortex. Moreover, high activation of the medial prefrontal cortex (PFC) facilitated proneness to both types of aggression equally. Whereas stimulation of the right ventrolateral (VLPFC) and dorsolateral (DLPFC) reduced proneness to aggression, inhibition of the left DLPFC increased it. Finally, psychophysiological and hormonal correlates in general did not clearly differentiate between the two types because they were equally related to each type (e.g., low basal cortisol and vagal variability in response to acute stress) CONCLUSIONS: This study reinforces the complementary model of both types of aggression instead of a dichotomous model. Additionally, this review also offers background about several treatments (i.e., pharmacological, non-invasive brain techniques…) to reduce aggression proneness.

The Legacy of the Kennard Principle

Research into neural plasticity has progressed rapidly over the last few decades, but the origins of this field lie in the early 20th century. In 1936, Margaret Kennard introduced the concept of brain plasticity in an animal model by studying the recovery of motor functions after performing brain lesions in infant and adult monkeys. It took until the 1970s for her work to be widely acknowledged. When her work did eventually make it into the limelight, this led to the synthesis of what scientists dubbed the 'Kennard Principle'. The Kennard Principle states that the younger an organism is, the greater and swifter recovery from brain injury will be. This principle itself is subject to controversy and debate; furthermore, it is based on a simplification of Kennard's original results. This article will explore Kennard's original 1936 paper, published in the American Journal of Physiology, and the context in which the Kennard Principle arose. Kennard's paper demonstrates early pioneering work within the field of behavioral neuroscience which provides a historical foundation for psychology and neuroscience undergraduates. Exploring the context in which the Kennard Principle arose also highlights the importance of tracing the origins of scientific principles and theories for students and researchers alike.