Comorbid depression and heart rate variability as predictors of aggressive and hyperactive symptom responsiveness during inpatient treatment of conduct-disordered, ADHD boys

The relationship between depression severity and heart rate variability in children and adolescents: A meta-analysis

OBJECTIVE

Depression in children and adolescents has gradually attracted social attention. Heart rate variability (HRV) has been found to be influenced by depression severity, but results have not been uniformed in children and adolescents. This study investigated the relationship between depression severity and heart rate variability in children and adolescents, aiming to provide additional evidence for an objective, effective, and convenient depression screening tool in this population.

METHODS

Literature searching was conducted in China National Knowledge Infrastructure (CNKI), Wanfang Data, Web of Science, PubMed, ScienceDirect, and EBSCO. Relevant studies investigating the relationship between depression severity and HRV in children and adolescents were selected for meta-analysis.

RESULTS

31 articles were included in this meta-analysis, involving 4534 participants. Depression severity in children and adolescents was significantly negatively correlated with high frequency (HF) and root mean square of successive differences (RMSSD) in HRV (HF: r = -0.10, 95% CI: -0.17 to -0.04, p = 0.001; RMSSD: r = -0.18, 95% CI: -0.30 to -0.05, p = 0.01). The relationship between HF and depression severity was moderated by age, higher among those aged >12 than among those aged <12 (r = -0.17, -0.02, Q = 7.32, p = 0.007).

CONCLUSION

Heart rate variability is associated with depression severity in children and adolescents.

Heart rate variability in children and adolescents with major depressive disorder: A systematic review and meta-analysis

Although reduced heart rate variability (HRV) has been observed in adults with major depressive disorder (MDD), the correlation between HRV and MDD in children and adolescents remains uncertain and requires to be systematically reviewed. Our meta-analysis included ten articles comprising 410 MDD patients and 409 healthy controls. Adolescents with MDD showed significant reductions in most HRV measures, such as HF-HRV, RMSSD, and PNN50, and depressive symptom severity was statistically associated with RMSSD, HF-HRV, and LF/HF ratio. A large heterogeneity across studies was detected. Sensitivity analysis revealed that removal of a specific study would significantly decline the heterogeneity for measures of HF-HRV, LF-HRV, and SDNN, and meta-regression analysis found that sample size and year of publication substantially moderated the differences between depressed samples and controls in RMSSD. Compared with adults, depression-induced autonomic dysfunction was more detectable in children and adolescents with substantial effects. Moreover, excluded studies which reported both HRV and MDD or depression symptoms were summarized based on objectives. Findings indicate that it is promising for HRV to be an appropriate and objective candidate biomarker for clinically depressed children and adolescents.

A Systematic Review of Primary and Secondary Callous-Unemotional Traits and Psychopathy Variants in Youth

Two variants of callous-unemotional (CU) traits and psychopathy have been proposed, referred to as primary and secondary. Whereas primary variants are thought to be underpinned by insufficient arousal to emotional cues, secondary variants are thought to develop as a coping mechanism in response to trauma exposure. Compared with adult samples, research on primary and secondary variants in children and adolescents under the age of 18 has only emerged in the past decade, and there is ongoing debate with regards to the identification, defining characteristics, and distinct correlates of these variants. The present systematic review synthesizes the current literature on primary and secondary variants in relation to: (1) constructs used to distinguish and define primary and secondary variants; (2) study population characteristics; (3) data analytic techniques to differentiate variants; and (4) differential associations with theoretically relevant indices related to emotional processing, maltreatment, biomarkers, and behavioral outcomes (e.g., substance use, aggression). This is the first systematic review to examine the growing literature on primary and secondary CU and psychopathy variants among youth. Findings support the distinction between youth with primary versus secondary variants and demonstrate that this distinction is related to unique clinical correlates. Recommendations are made for future research in the field.

Neurocognitive predictors of treatment completion and daytime activities at follow-up in multiproblem young adults

Previous research has shown an association between cognitive control deficits and problematic behavior such as antisocial behavior and substance use, but little is known about the predictive value of cognitive control for treatment outcome. The current study tests whether selected markers of baseline cognitive control predict (1) treatment completion of a day treatment program involving a combination of approaches for multiproblem young adults and (2) daytime activities a year after the start of treatment, over and above psychological, social, and criminal characteristics. We assessed individual, neurobiological, and neurobehavioral measures, including functional brain activity during an inhibition task and two electroencephalographic measures of error processing in 127 male multiproblem young adults (age 18-27 years). We performed two hierarchical regression models to test the predictive power of cognitive control for treatment completion and daytime activities at follow-up. The overall models did not significantly predict treatment completion or daytime activities at follow-up. However, activity in the anterior cingulate cortex (ACC) during response inhibition, years of regular alcohol use, internalizing problems, and ethnicity were all significant individual predictors of daytime activity at follow-up. In conclusion, cognitive control could not predict treatment completion or daytime activities a year after the start of treatment over and above individual characteristics. However, results indicate a direct association between brain activity during response inhibition and participation in daytime activities, such as work or school, after treatment. As adequate baseline inhibitory control is associated with a positive outcome at follow-up, this suggests interventions targeting cognitive control might result in better outcomes at follow-up.

Changes in heart rate and skin conductance in the 30 min preceding aggressive behavior

Aggressive behavior of inpatients threatens the safety and well-being of both mental health staff members and fellow patients. It was investigated whether heart rate and electrodermal activity can be used to signal imminent aggression. A naturalistic study was conducted in which 100 inpatients wore sensor wristbands during 5 days to monitor their heart rate and electrodermal activity while staff members recorded patients' aggressive incidents on the ward. Of the 100 patients, 36 displayed at least one aggressive incident. Longitudinal multilevel models indicated that heart rate, skin conductance level, and the number of nonspecific skin conductance responses per minute rose significantly in the 20 min preceding aggressive incidents. Although psychopathy was modestly correlated with displaying aggression, it was not a significant predictor of heart rate and skin conductance preceding aggression. The current findings may provide opportunities for the development of individual prediction models to aid acute risk assessment and to predict aggressive incidents in an earlier stage. The current results on the physiological indicators of aggression are promising for reducing aggression and improving both staff as well as patient safety in psychiatric mental health institutions.

Effect of Comorbid Psychopathology and Conduct Problem Severity on Response to a Multi-component Intervention for Childhood Disruptive Behavior

This study examined the effects of comorbid ADHD symptoms, internalizing psychopathology, Callous-Unemotional (CU) Traits, and conduct problem severity on children's response to an evidence-based psychosocial intervention. Clinic-referred children with DBD ages 8-12 years (N = 76) participated in a 15-week multi-component intervention. Parents provided weekly ratings of children's oppositionality-defiance, peer problems, and impairment. Oppositionality-defiance, peer problems, and impairment decreased significantly over the course of the intervention; however, there was considerable variability in weekly ratings. Baseline ADHD symptoms, internalizing psychopathology, CU traits, and conduct problem severity were unrelated to rate of change across treatment. However, ADHD symptoms uniquely predicted more oppositionality-defiance, peer problems, and impairment averaged across the 15 weeks of treatment. Follow-up analyses suggested this was driven by hyperactivity-impulsivity rather than inattention. Children with DBD and comorbid symptoms appear to benefit from a multi-component intervention, but those with ADHD symptoms may require additional support to address social and behavioral challenges.

Quantifying respiratory sinus arrhythmia: Effects of misspecifying breathing frequencies across development

Low resting respiratory sinus arrhythmia (RSA), and to a lesser extent excessive RSA reactivity to emotion evocation, are observed in many psychiatric disorders characterized by emotion dysregulation, including syndromes spanning the internalizing and externalizing spectra, and other conditions such as nonsuicidal self-injury. Nevertheless, some inconsistencies exist. For example, null outcomes in studies of RSA–emotion dysregulation relations are sometimes observed among younger participants. Such findings may derive from use of age inappropriate frequency bands in calculating RSA. We combine data from five published samples (N = 559) spanning ages 4 to 17 years, and reanalyze RSA data using age-appropriate respiratory frequencies. Misspecifying respiratory frequencies results in overestimates of resting RSA and underestimates of RSA reactivity, particularly among young children. Underestimates of developmental shifts in RSA and RSA reactivity from preschool to adolescence were also observed. Although correlational analyses revealed weak negative associations between resting RSA and aggression, those with clinical levels of externalizing exhibited lower resting RSA than their peers. No associations between RSA reactivity and externalizing were observed. Results confirm that age-corrected frequency bands should be used when estimating RSA, and that literature-wide overestimates of resting RSA, underestimates of RSA reactivity, and underestimates of developmental shifts in RSA and RSA reactivity may exist.

ADHD and Emotion Dysregulation Among Children and Adolescents

Individuals with attention-deficit/hyperactivity disorder (ADHD) experience impairments in a number of functional domains. Although current evidence-based treatments for ADHD reduce symptoms and improve academic and behavioral functioning, they have minimal impact on social functioning or on risky behaviors (see Evans et al. in J Clin Child Adolesc Psychol, 43:527-551, 2014 for review). Preliminary evidence indicates that emotion dysregulation (ED) is associated with impairments across the developmental spectrum, such as social impairment and risky behaviors, and that its relative absence/presence is differentially associated with treatment response. It thus stands to reason that by incorporating a focus on ED in interventions targeting social impairment and risky behaviors, we may be able to increase the number of youth who respond to such interventions and decrease the prevalence or degree of these impairments and behaviors among youth and adults with ADHD. However, a number of questions remain unaddressed about the association between ADHD and ED, such as the portion of individuals with ADHD who experience ED, the extent to which ED is associated with the above impairments and behaviors, and whether or not ED is malleable. To begin addressing these questions, we summarize and critically evaluate the literature on the association between ADHD and ED and make recommendations for future basic, translational, and treatment outcome research.

START NOW - a comprehensive skills training programme for female adolescents with oppositional defiant and conduct disorders: study protocol for a cluster-randomised controlled trial

Background

In Europe, the number of females exhibiting oppositional defiant disorder (ODD) and conduct disorder (CD) is growing. Many of these females live in youth welfare institutions. Consequently, there is a great need for evidence-based interventions within youth welfare settings. A recently developed approach targeting the specific needs of girls with ODD and CD in residential care is START NOW. The aim of this group-based behavioural skills training programme is to specifically enhance emotional regulation capacities to enable females with CD or ODD to appropriately deal with daily-life demands. It is intended to enhance psychosocial adjustment and well-being as well as reduce oppositional and aggressive behaviour. We present the study protocol (version 4.1; 10 February 2016) of the FemNAT-CD intervention trial titled ‘Group-Based Treatment of Adolescent Female Conduct Disorders: The Central Role of Emotion Regulation’.

Methods/design

The study is a prospective, confirmatory, cluster-randomised, parallel-group, multi-centre, randomised controlled trial with 128 institutionalised female adolescents who fulfil the diagnostic criteria of ODD and/or CD. Institutions/wards will be randomised either to provide the 12-week skills training as an add-on intervention or to provide treatment as usual. Once the first cycle is completed, each institution will run a second cycle with the opposite condition. Primary endpoints are the pre-post change in number of CD/ODD symptoms as assessed by a standardised, semi-structured psychiatric interview (Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children–Present and Lifetime, CD/ODD section) between baseline and the end of intervention, as well as between baseline and a 3-month follow-up point. Secondary objectives include pre-post change in CD/ODD-related outcome measures, most notably emotional regulation on a behavioural and neurobiological level after completion of START NOW compared with treatment as usual.

Discussion

To our knowledge, this study is the first to date to systematically investigate the effectiveness of an adapted integrative psychosocial intervention designed for female adolescents with ODD and CD in youth welfare settings.

Trial registration

German Clinical Trials Register (DRKS) identifier: DRKS00007524. Registered on 18 December 2015 and with the World Health Organisation International Clinical Trials Registry Platform.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1705-6) contains supplementary material, which is available to authorized users.

The role of anxiety in the development, maintenance, and treatment of childhood aggression

The majority of aggressive children exhibit symptoms of anxiety, yet none of our developmental models of aggression incorporate the role of anxiety, and our treatments ignore this comorbidity. This article outlines a novel theoretical model that specifies three hypotheses about comorbid anxious and aggressive children: (a) unpredictable parenting induces anxiety in children that in turn triggers aggressive behavior; (b) prolonged periods of anxiety deplete children's capacity to inhibit impulses and trigger bouts of aggression, and aggression in turn functions to regulate levels of anxiety; and (c) minor daily stressors give rise to anxiety while cognitive perseveration maintains anxious moods, increasingly disposing children to aggress. Little or no research has directly tested these hypotheses. Extant research and theory consistent with these claims are herein reviewed, and future research designs that can test them specifically are suggested. The clinical implications most relevant to the hypotheses are discussed, and to improve the efficacy of treatments for childhood aggression, it is proposed that anxiety may need to be the primary target of treatment.

Neurobiological factors as predictors of cognitive-behavioral therapy outcome in individuals with antisocial behavior: a review of the literature

This review focuses on the predictive value of neurobiological factors in relation to cognitive-behavioral therapy outcome among individuals with antisocial behavior. Ten relevant studies were found. Although the literature on this topic is scarce and diverse, it appears that specific neurobiological characteristics, such as physiological arousal levels, can predict treatment outcome. The predictive value of neurobiological factors is important as it could give more insight into the causes of variability in treatment outcome among individuals with antisocial behavior. Furthermore, results can contribute to improvement in current treatment selection procedures and to the development of alternative treatment options.

The contributions of early adverse experiences and trajectories of respiratory sinus arrhythmia on the development of neurobehavioral disinhibition among children with prenatal substance exposure

Neurobehavioral disinhibition (ND) is a complex condition reflecting a wide range of problems involving difficulties with emotion regulation and behavior control. Respiratory sinus arrhythmia (RSA) is a physiological correlate of emotion regulation that has been studied in a variety of at-risk populations; however, there are no studies of RSA in children with ND. Data were drawn from a prospective longitudinal study of prenatal substance exposure that included 1,073 participants. Baseline RSA and RSA reactivity to an attention-demanding task were assessed at 3, 4, 5, and 6 years. ND was assessed at ages 8/9, 11, and 13/14 years via behavioral dysregulation and executive dysfunction composite measures. Greater exposure to early adversity was related to less RSA reactivity at 3 years, increases in RSA reactivity from ages 3 to 6 years, and increased behavioral dysregulation from ages 8/9 to 13/14. RSA reactivity was examined as a moderator of the association between early adversity and changes in ND. A significant Early Adversity × RSA Reactivity quadratic interaction revealed that children with decelerations in RSA reactivity exhibited increases in behavioral dysregulation, regardless of their exposure to early adversity. However, greater exposure to early adversity was related to greater increases in behavioral dysregulation, but only if children exhibited accelerations in RSA reactivity from ages 3 to 6 years. The results contribute to our understanding of how interactions across multiple levels of analysis contribute to the development of ND.

Parent training for children born premature: a pilot study examining the moderating role of emotion regulation

The aim of the current study was to examine the moderating effect of emotion regulation on treatment efficacy following a parent-training intervention, parent-child interaction therapy, for young children born preterm. In this pilot randomized controlled trial, 28 young children who were born preterm (i.e., <37 weeks gestation) and presented with elevated levels of externalizing behavior problems were randomly assigned to an immediate treatment or waitlist control group. Observers masked to treatment condition coded an index of emotion regulation (i.e., global regulation) during a videotaped 10-min parent-child interaction at the initial baseline assessment. Treatment efficacy was assessed using a parent-report questionnaire of child disruptive behavior. Results demonstrated that global regulation significantly interacted with treatment condition in predicting change in child disruptive behavior. Specifically, higher levels of distress at baseline were associated with greater improvements in child disruptive behavior following the intervention. These findings are discussed in the context of the differential susceptibility hypothesis and highlight the importance of considering children's emotion regulation skills in the course of psychosocial treatment for young children born premature.

Early adverse care, stress neurobiology, and prevention science: lessons learned

There is growing evidence that some of the difficulties observed among children who have experienced early adverse care (e.g., children internationally adopted from institutional care and maltreated children in foster care) involve experience-induced alterations in stress-responsive neurobiological systems, including the hypothalamic-pituitary-adrenocortical (HPA) system. Thus, incorporating stress neurobiology into prevention research could aid in identifying the children most in need of preventive intervention services, elucidating the mechanisms of change in effective interventions, and providing insight into the differential responses of children to effective interventions. However, integrating stress neurobiology and prevention research is challenging. In this paper, the results of studies examining HPA system activity in children who have experienced early adverse care are reviewed, the implications of these results for prevention research are discussed, and critical steps for successfully incorporating stress neurobiology into prevention research are identified.

Cardiac vagal control and children's adaptive functioning: a meta-analysis

Polyvagal theory has influenced research on the role of cardiac vagal control, indexed by respiratory sinus arrhythmia withdrawal (RSA-W) during challenging states, in children's self-regulation. However, it remains unclear how well RSA-W predicts adaptive functioning (AF) outcomes and whether certain caveats of measuring RSA (e.g., respiration) significantly impact these associations. A meta-analysis of 44 studies (n=4996 children) revealed small effect sizes such that greater levels of RSA-W were related to fewer externalizing, internalizing, and cognitive/academic problems. In contrast, RSA-W was differentially related to children's social problems according to sample type (community vs. clinical/at-risk). The relations between RSA-W and children's AF outcomes were stronger among studies that co-varied baseline RSA and in Caucasian children (no effect was found for respiration). Children from clinical/at-risk samples displayed lower levels of baseline RSA and RSA-W compared to children from community samples. Theoretical/practical implications for the study of cardiac vagal control are discussed.

Revisiting the treatment of conduct problems in children with callous-unemotional traits

OBJECTIVE

This study examined whether the diminished treatment response previously reported for children with conduct problems and high levels of callous-unemotional (CU) traits is evident when these traits are indexed using multi-informant data collected from mothers, fathers, and teachers. It also tested whether treatment outcomes associated with CU traits are independent of overlap between CU traits and autism spectrum disorder (ASD) symptoms.

METHOD

Diagnostic data on oppositional defiant disorder (ODD) severity were collected pre-treatment (time 1) and at 6-month follow-up (time 2) in a sample of children (N = 95; 67 boys, 28 girls) aged 3-9 years with clinic-referred conduct problems and comorbid symptoms in a range of diagnostic domains. Time 1 measures of CU traits and ASD symptoms were tested as predictors of time 2 ODD severity using structural equation modeling, with multi-informant ratings of CU traits modeled as a single latent variable.

RESULTS

Compared to children with low levels of CU traits, those with high levels exhibited more severe ODD symptoms at follow-up (β = 0.33, SE = 0.08, p < 0.05), after controlling for pre-treatment severity, socio-economic status, other demographics (age, gender), and parameters of treatment (number of treatment sessions, medication status). Although CU traits and ASD symptoms were positively correlated, ASD symptoms showed no association with change in ODD severity from pre-treatment to follow-up. Likewise, the association between CU traits and ODD outcomes held when controlling for covariation between CU traits and ASD symptoms.

CONCLUSIONS

Our findings replicate previous evidence that CU traits are uniquely associated with poor clinical outcomes among children treated for conduct problems, and show for the first time that this association is not accounted for by symptoms of ASD.

An initial investigation of baseline respiratory sinus arrhythmia as a moderator of treatment outcome for young children born premature with externalizing behavior problems

The aim of the current study was to examine the moderating effect of baseline respiratory sinus arrhythmia (RSA) on Parent-Child Interaction Therapy (PCIT), a behavioral parent-training intervention, for young children born premature. In this pilot randomized controlled trial, 28 young children (mean age of 37.79 months), who were born <37 weeks gestation and presented with elevated externalizing behavior problems, were randomly assigned to an immediate treatment or waitlist control group. RSA, which provides an approximate marker of individual differences in cardiac vagal tone, was measured during a baseline period. Past research has generally shown that higher levels of baseline RSA correlate with various positive psychological states (e.g., empathy, sustained attention), whereas lower levels of baseline RSA correlate with less optimal psychological states (e.g., higher externalizing behavior problems). Results indicated that baseline RSA significantly interacted with treatment condition in predicting changes in child disruptive behavior. Specifically, low levels of baseline RSA were associated with greater improvements in child disruptive behavior following PCIT. While acknowledging the caveats of measuring and interpreting RSA and the need to include a sympathetic-linked cardiac measure in future research, these findings provide preliminary evidence that children with lower capacity for emotion regulation receive even greater treatment gains. Future research should also examine the moderating effect of RSA in larger samples and explore the potential mediating role of RSA on behavioral parenting interventions.

Instantiating the multiple levels of analysis perspective in a program of study on externalizing behavior

During the last quarter century, developmental psychopathology has become increasingly inclusive and now spans disciplines ranging from psychiatric genetics to primary prevention. As a result, developmental psychopathologists have extended traditional diathesis-stress and transactional models to include causal processes at and across all relevant levels of analysis. Such research is embodied in what is known as the multiple levels of analysis perspective. We describe how multiple levels of analysis research has informed our current thinking about antisocial and borderline personality development among trait impulsive and therefore vulnerable individuals. Our approach extends the multiple levels of analysis perspective beyond simple Biology × Environment interactions by evaluating impulsivity across physiological systems (genetic, autonomic, hormonal, neural), psychological constructs (social, affective, motivational), developmental epochs (preschool, middle childhood, adolescence, adulthood), sexes (male, female), and methods of inquiry (self-report, informant report, treatment outcome, cardiovascular, electrophysiological, neuroimaging). By conducting our research using any and all available methods across these levels of analysis, we have arrived at a developmental model of trait impulsivity that we believe confers a greater understanding of this highly heritable trait and captures at least some heterogeneity in key behavioral outcomes, including delinquency and suicide.

Perinatal risk factors in the development of aggression and violence

Over the past several decades, the relative contribution of both environmental and genetic influences in the development of aggression and violence has been explored extensively. Only fairly recently, however, has it become increasingly evident that early perinatal life events may substantially increase the vulnerability toward the development of violent and aggressive behaviors in offspring across the lifespan. Early life risk factors, such as pregnancy and birth complications and intrauterine exposure to environmental toxins, appear to have a profound and enduring impact on the neuroregulatory systems mediating violence and aggression, yet the emergence of later adverse behavioral outcomes appears to be both complex and multidimensional. The present chapter reviews available experimental and clinical findings to provide a framework on perinatal risk factors that are associated with altered developmental trajectories leading to violence and aggression, and also highlights the genetic contributions in the expression of these behaviors.

Changes in maternal depression are associated with MST outcomes for adolescents with co-occurring externalizing and internalizing problems

The efficacy of Multisystemic therapy (MST) in treating adolescent aggression has been established, however, not all youth and their families benefit from MST. One reason for this treatment variability could be the failure to distinguish between different aggressive subtypes with different risk factors, developmental prognoses and treatment needs. We investigated whether changes in maternal depression over MST would lead to different outcomes for two aggressive subtypes: pure externalizers (EXT) and mixed externalizers/internalizers (MIXED). Forty-two EXT and 27 MIXED youth and their families underwent MST for six months. Maternal depression, youth externalizing and internalizing behaviour were assessed before and after MST. Results showed a marginally greater change in externalizing for EXT youth. In addition, reductions in maternal depression were related to successful treatment outcomes for MIXED youth only. Our findings have implications for MST clinicians, namely the importance of reducing depressive symptoms in mothers of MIXED youth to improve their outcomes.

Family intervention effects on co-occurring early childhood behavioral and emotional problems: a latent transition analysis approach

This study used latent transition analysis (LTA) to examine changes in early emotional and behavioral problems in children age 2 to 4 years resulting from participation in a family-centered intervention. A sample of 731 economically disadvantaged families was recruited from among participants in a national food supplement and nutrition program. Families with toddlers between age 2 and 3 were randomized either to the Family Check-Up (FCU) or to a nonintervention control group. The FCU's linked interventions were tailored to each family's needs. Assessments occurred at age 2, 3, and 4. The FCU followed age 2 and age 3 assessments. Latent class analyses were conducted on mother reports of behavior and emotional problems from age 2 to 4 to study transitions among the following four groups: (a) externalizing only, (b) internalizing only, (c) comorbid internalizing and externalizing, and (d) normative. LTA results revealed that participation in the FCU increased the likelihood of transitioning from either the comorbid or the internalizing class into the normative class by age 4. These results suggest family interventions in early childhood can potentially disrupt the early emergence of both emotional and behavioral problems.

Ten good reasons to consider biological processes in prevention and intervention research

Most contemporary accounts of psychopathology acknowledge the importance of both biological and environmental influences on behavior. In developmental psychopathology, multiple etiological mechanisms for psychiatric disturbance are well recognized, including those operating at genetic, neurobiological, and environmental levels of analysis. However, neuroscientific principles are rarely considered in current approaches to prevention or intervention. In this article, we explain why a deeper understanding of the genetic and neural substrates of behavior is essential for the next generation of preventive interventions, and we outline 10 specific reasons why considering biological processes can improve treatment efficacy. Among these, we discuss (a) the role of biomarkers and endophenotypes in identifying those most in need of prevention; (b) implications for treatment of genetic and neural mechanisms of homotypic comorbidity, heterotypic comorbidity, and heterotypic continuity; (c) ways in which biological vulnerabilities moderate the effects of environmental experience; (d) situations in which Biology x Environment interactions account for more variance in key outcomes than main effects; and (e) sensitivity of neural systems, via epigenesis, programming, and neural plasticity, to environmental moderation across the life span. For each of the 10 reasons outlined we present an example from current literature and discuss critical implications for prevention.

Dissociation of sad facial expressions and autonomic nervous system responding in boys with disruptive behavior disorders

Although deficiencies in emotional responding have been linked to externalizing behaviors in children, little is known about how discrete response systems (e.g., expressive, physiological) are coordinated during emotional challenge among these youth. We examined time-linked correspondence of sad facial expressions and autonomic reactivity during an empathy-eliciting task among boys with disruptive behavior disorders (n=31) and controls (n=23). For controls, sad facial expressions were associated with reduced sympathetic (lower skin conductance level, lengthened cardiac preejection period [PEP]) and increased parasympathetic (higher respiratory sinus arrhythmia [RSA]) activity. In contrast, no correspondence between facial expressions and autonomic reactivity was observed among boys with conduct problems. Furthermore, low correspondence between facial expressions and PEP predicted externalizing symptom severity, whereas low correspondence between facial expressions and RSA predicted internalizing symptom severity.

Cardiac vagal control in depression: a critical analysis

Rapidly developing research has found abnormal cardiac vagal control (CVC) in several physical and mental health conditions. CVC findings in depression are mixed, and the degree to which CVC is compromised in depression is unclear. A meta-analysis of 13 rigorous cross-sectional studies reveals that a diagnosis of depression exerts a small-to-medium effect size on CVC, and explains only about 2% of the overall variance in CVC. More robust data may emerge from alternative approaches to the depression-CVC relationship, such as the use of CVC to predict the course of the disorder. Despite the vigor of recent work on CVC and depression, overall findings are suggestive rather than conclusive. Methodological desiderata and priorities for future research are discussed, including the need to clarify the etiological significance of CVC.

Autonomic correlates of attention-deficit/hyperactivity disorder and oppositional defiant disorder in preschool children

Numerous studies have revealed autonomic underarousal in conduct-disordered adolescents and antisocial adults. It is unknown, however, whether similar autonomic markers are present in at-risk preschoolers. In this study, the authors compared autonomic profiles of 4- to 6-year-old children with attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD; n = 18) with those of age-matched controls (n = 20). Children with ADHD and ODD exhibited fewer electrodermal responses and lengthened cardiac preejection periods at baseline and during reward. Although group differences were not found in baseline respiratory sinus arrhythmia, heart rate changes among ADHD and ODD participants were mediated exclusively by parasympathetic withdrawal, with no independent sympathetic contribution. Heart rate changes among controls were mediated by both autonomic branches. These results suggest that at-risk preschoolers are autonomically similar to older externalizing children.

The treatment of conduct problems in children with callous-unemotional traits

The aim of this study was to examine the impact of callous-unemotional (CU) traits on treatment outcomes and processes in a 10-week behavioral parent-training intervention with young boys referred for conduct problems (N = 56; mean age 6.29 years). CU traits were associated with greater conduct problems at pretreatment and with poor outcomes at 6-month follow-up. CU traits uniquely predicted clinical outcomes when analyzed in relation to conduct-problem severity, other predictors of antisocial behavior, and parents' implementation of treatment. Boys with high CU traits were less responsive to discipline with time-out than boys without CU traits and reacted to this discipline with less affect. These findings present important implications for the role of child temperament in intervention for conduct problems.

Escalated aggressive behavior: Dopamine, serotonin and GABA

The ethical dilemma in aggression research is how to reconcile two divergent objectives, namely to avoid harm and injury as much as possible and, at the same time, how to study behavioral phenomena that validly represent the essence of the neurobiology of aggression. Clinical and preclinical aggression research focuses on different types of aggression. Preclinical studies are usually stimulated by an ethological approach and focus on the phylogeny, ontogeny, survival value and neural mechanisms of ritualized displays and signals. On the other hand, clinical studies focus on violent individuals and pathologically excessive forms of aggressive behavior. This review emphasizes research on escalated forms of aggression in animals and humans and their pharmacotherapy. The current experimental models to generate escalated levels of aggressive behavior in laboratory rely on social instigation, frustrative non-reward and alcohol drinking. These types of aggression are modulated by canonical neurotransmitters like dopamine, serotonin (5-HT) and GABA. It continues to be a main goal of much neurobiological research to find potential targets of pharmacological agents that interact with dopaminergic, GABAergic and serotonergic systems and have high efficacy and selectivity to reduce excessive levels of aggressive and violent behaviors without side-effects. While the mesocorticolimbic dopamine system is implicated in the initiation, execution, termination and consequences of aggressive behavior, drugs with a high affinity for dopamine D2 receptors lack specificity for reducing aggressive behavior. Current investigations point to 5-HT(1B) receptor subtypes as particularly relevant. First, they are differentially expressed in aggression-prone individuals relative to those who are not excessively aggressive. Second, these and also other 5-HT receptor subtypes emerge to be significant targets for anti-aggressive interventions. Positive modulators of GABA(A) receptors with specific subunit configuration may be relevant for heightening aggression, and these sites may be targets for intervention. A prerequisite for rational pharmacotherapies will be adequate characterization of serotonergic and GABAergic receptor regulation in individuals exhibiting escalated aggression.

Varieties of attention-deficit/hyperactivity disorder-related intra-individual variability

Intra-individual variability in behavior and functioning is ubiquitous among children with attention-deficit/hyperactivity disorder (ADHD), but it has not been systematically examined or integrated within causal models. This article seeks to provide a conceptual, methodologic, and analytic framework as a foundation for future research. We first identify five key research questions and methodologic issues. For illustration, we examine the periodic structure of Eriksen Flanker task reaction time (RT) data obtained from 24 boys with ADHD and 18 age-matched comparison boys. Reaction time variability in ADHD differed quantitatively from control subjects, particularly at a modal frequency around .05 Hz (cycle length approximately 20 sec). These oscillations in RT were unaffected by double-blind placebo and were suppressed by double-blind methylphenidate. Together with converging lines of basic and clinical evidence, these secondary data analyses support the speculative hypothesis that the increased power of multisecond oscillations in ADHD RT data, and by inference, in attentional performance, represents a catecholaminergic deficit in the ability to appropriately modulate such oscillations in neuronal activity. These results highlight the importance of retaining time-series data and quantitatively examining intra-subject measures of variability as a putative endophenotype for ADHD.

Mediators, Moderators, and Predictors of 1-Year Outcomes Among Children Treated for Early-Onset Conduct Problems: A Latent Growth Curve Analysis

Several child conduct problem interventions have been classified as either efficacious or well established. Nevertheless, much remains to be learned about predictors of treatment response and mechanisms of behavioral change. In this study, the authors combine data from 6 randomized clinical trials and 514 children, ages 3.0-8.5 years, to evaluate moderators, mediators, and predictors of outcome. Among other findings, latent growth curve models of mother-report and observational measures of child externalizing behaviors suggested that marital adjustment, maternal depression, paternal substance abuse, and child comorbid anxiety/depression each moderated treatment response. Moreover, critical, harsh, and ineffective parenting both predicted and mediated outcome, with the most favorable responses observed when parents scored relatively low on each construct at intake yet improved during treatment. Implications for treatment nonresponders are discussed.

Disinhibitory psychopathology in male adolescents: discriminating conduct disorder from attention-deficit/hyperactivity disorder through concurrent assessment of multiple autonomic states

T. P. Beauchaine recently proposed a model of autonomic nervous system functioning that predicts divergent patterns of psychophysiological responding across disorders of disinhibition. This model was tested by comparing groups of male adolescents with attention-deficit/hyperactivity disorder (ADHD) and attention-deficit/hyperactivity disorder plus conduct disorder (CD/ADHD) with controls while performing a repetitive motor task in which rewards were administered and removed across trials. Participants then watched a videotaped peer conflict. Electrodermal responding (EDR), cardiac pre-ejection period (PEP), and respiratory sinus arrhythmia (RSA) were monitored. Compared with controls, the ADHD and CD/ADHD participants exhibited reduced EDR. The CD/ADHD group was differentiated from the ADHD and control groups on PEP and from the control group on RSA. Findings are discussed in terms of the motivational and regulational systems indexed. Implications for understanding rates of comorbidity between CD and ADHD are considered.