Morphometric brain abnormalities in boys with conduct disorder

ObjectiveChildren with the early-onset type of conduct disorder (CD) are at high risk for developing an antisocial personality disorder. Although there have been several neuroimaging studies on morphometric differences in adults with antisocial personality disorder, little is known about structural brain aberrations in boys with CD.MethodMagnetic resonance imaging and voxel-based morphometry were used to assess abnormalities in gray matter volumes in 23 boys ages 12 to 17 years with CD (17 comorbid for attention-deficit/hyperactivity disorder) in comparison with age- and IQ-matched controls.ResultsCompared with healthy controls, mean gray matter volume was 6% smaller in the clinical group. Compared with controls, reduced gray matter volumes were found in the left orbitofrontal region and bilaterally in the temporal lobes, including the amygdala and hippocampus on the left side in the CD group. Regression analyses in the clinical group indicated an inverse association of hyperactive/impulsive symptoms and widespread gray matter abnormalities in the frontoparietal and temporal cortices. By contrast, CD symptoms correlated primarily with gray matter reductions in limbic brain structures.ConclusionsThe data suggest that boys with CD and comorbid attention-deficit/hyperactivity disorder show brain abnormalities in frontolimbic areas that resemble structural brain deficits, which are typically observed in adults with antisocial behavior.     

Biodevelopmental aspects of conduct disorder in boys

The association between biochemical parameters and conduct disorder (CD) was studied in 22 boys admitted to a residential center. Three-methoxy-4-hydroxyphenylglycol (MHPG) levels were significantly higher in prepubertal CD youth than in pubertal/post pubertal CD youth. Homovanillic acid (HVA) levels were significantly lower in CD youth under age 12.0 years than in non CD youth under age 12.0 years. The implications of these biodevelopmental findings in the study of CD are discussed.     

Response to emotional stimuli in boys with conduct disorder

OBJECTIVE: Boys with conduct disorder are at risk of persistently showing antisocial behavior in adult life, particularly if they have an additional diagnosis of attention deficit hyperactivity disorder (ADHD). In the search for biological risk factors that predispose children to the development of antisocial personality disorder, research has provided substantial data suggesting that autonomic hyporesponsiveness indicates a greater likelihood of future antisocial behavior. The purpose of this study was to examine autonomic arousal in boys with conduct disorder, comorbid conduct disorder and ADHD, and ADHD only. METHOD: In addition to self-ratings, electrodermal responses to pleasant, neutral, and unpleasant slides were obtained for 21 boys with conduct disorder and 54 boys with ADHD plus conduct disorder. Forty-three boys with a diagnosis of ADHD only were recruited as a clinical comparison group, and 43 boys with no conduct disorder or ADHD were included as a healthy comparison group. All subjects were ages 8-13 years. RESULTS: Compared to the healthy subjects and the subjects with ADHD only, the boys with conduct disorder and with ADHD plus conduct disorder reported lower levels of emotional response to aversive stimuli and lower autonomic responses to all slides independent of valence. CONCLUSIONS: Although the self-report data supported a deficit in reactivity to explicit fear cues, the psychophysiological data indicated that boys with conduct disorder both with and without a comorbid condition of ADHD are characterized by a generalized deficit in autonomic responsivity in an experimental situation in which children were exposed to complex visual stimuli of unpredictable affective quality. Psychophysiological findings may point to a deficit in associative information processing systems that normally produce adaptive cognitive-emotional reactions.     

Platelet 5-HT uptake in boys with conduct disorder

Dysregulation of serotonergic function has been found to be associated with aggression in animals, human adults and adolescents. However, studies with children have shown conflicting results. The objective of this study was to investigate whether the kinetic characteristics (Vmax and Km) of 5-HT uptake in platelets are different in children with the diagnosis of conduct disorder according to ICD-10 and healthy age-matched controls. In addition to the standardized assessment of general psychopathology, methods assessing narrowband aggressive symptoms (Child Behavior Checklist) and emotional reactivity to an experimentally induced provocation (Taylor's competitive reaction time task) were used in both groups. We found a trend for a lower mean Vmax of platelet 5-HT uptake in 14 conduct-disordered boys compared with healthy controls (n=15). If, however, 2 patients with a low degree of aggression and emotional reactivity were excluded, the difference became significant (mean=4.27, SD=3.49 in patients and mean=8.45, SD=4.63 in controls). A significant negative correlation was found between parent-rated aggression scores and Vmax (r=-0.41, p < 0.05, n=29). These data suggest that dysfunction of 5-HT transport mechanisms might be associated with specific behavioral symptoms in conduct-disordered children.     

Response to social and monetary reward in neurosis

Operant response to positive reinforcement in the form of verbal and monetary reward was tested with twenty Behavior Disordered (neurotic patients defined by a history of anti-social illegal activities), twenty Dysthmic (neurotic patients with no history of anti-social illegal activities), and twenty Normal (non-patient volunteer) subjects. The Behavior Disordered were more responsive to verbal approval and modified their behavior to obtain approval to a greater extent than either of the other groups. They were more persistent in responding in the monetary reward situation, although the Normals were more successful in terms of total amount of money obtained. These results support the outcome of a previous study by the present authors and clinical experience, but are inconsistent with reports that Dysthymics are more responsive to verbal approval. It is suggested that the interaction of the personality characteristics of the subject with the sex and status of the experimenter may be critical in determining responsiveness. Behavior Disordered subjects are likely to be more responsiveness to peers and to those of the opposite sex, and Dysthymics to those of higher status.     

A two-year follow-up of boys with aggressive conduct disorder

53 boys with aggressive conduct disorder (ACD) and 36 with other psychiatric disorders were followed up after 2 years. Twenty-nine of the former (55%) still met the criteria for ACD; 24 did not. Persistence of the conduct disorder was predicted by the symptoms of hyperactivity and inattention. The data suggest that there are two types of ACD: one short-lived and quite benign, the other more likely to persist and more serious.     

Similar autonomic responsivity in boys with conduct disorder and their fathers

OBJECTIVE: Antisocial behavior frequently occurs in families. This study investigated whether autonomic hypoarousal and hyporesponsivity, which have been observed in antisocial individuals of all ages, are passed from fathers to male offspring. METHOD: The study included 44 boys with early-onset conduct disorder and 36 healthy controls (8 to 13 years old) together with their biological fathers. Resting heart rate and nonspecific skin conductance fluctuations were assessed as arousal measurements, with electrodermal responses and heart rate changes to pictorial stimuli serving as response measurements. In addition, boys and fathers were subjected to psychometric measurements of antisocial behavior. RESULTS: The fathers of boys with CD showed significantly lower electrodermal responses to pictures of either emotional quality than the fathers of controls (p between.015 and < .001), and they revealed fewer nonspecific skin conductance fluctuations (p = .001). In addition, they reported a more aggressive, hostile, and impulsive behavioral style. Psychophysiological measurements were highly correlated between fathers and sons (p between .007 and < .001), and fathers' autonomic responses accounted for group differences in electrodermal responses between boys (p < .001). CONCLUSIONS: The fathers of boys with conduct disorder exhibited an abnormal psychophysiological response pattern similar to that of their sons. High father-son correlations in psychophysiological measures raise the question of whether autonomic abnormalities may constitute a biological mediator through which the disposition for antisocial behavior is transmitted within families.     

Diagnostic threshold for conduct disorder in girls and boys

Concerns about gender bias in the diagnostic criteria for conduct disorder (CD) have prompted some researchers to recommend that the diagnostic threshold in girls be lowered. Since CD is a highly familial condition, the authors assessed the diagnostic validity of subthreshold CD in girls using family study methodology. They compared the rates of antisocial disorders (CD and antisocial personality disorder) in relatives of four groups of index children: children with attention deficit hyperactivity disorder (ADHD) and full, subthreshold, or no CD diagnoses and non-ADHD/non-CD control subjects. Results showed no interaction between gender and familiality across the four groups. Furthermore, there was no significant evidence of familiality of subthreshold CD. From a family genetic perspective, the diagnostic threshold for CD does not appear to differ by gender. The current results support the possibility that differential rates of CD reflect actual differences in rates of antisocial behavior across gender.     

The influence of monetary reward on proactive and reactive control in adolescent males

Adolescence is marked by increased reward-seeking, which can alter cognitive control abilities. Previous research found that rewards actually improve cognitive control in children, adolescents, and adults, but these studies only investigated reactive control. The goal of the current study was to elucidate reward’s influence on both proactive and reactive control during adolescence. To this end, 68 (Mean age = 13.61, SD = 2.52) male adolescents completed a rewarded cued flanker paradigm while electroencephalogram (EEG) was collected. Theta power and inter-channel phase synchrony, both implicated in cognitive control, were quantified after cues and stimuli to understand their role during reward-cognitive control interactions. The data suggest that reward reduced interference during reactive control; however, reward increased interference during proactive control in this sample of adolescent males. Reward-related increases in cue-locked theta power predicted more reward-related RT interference on proactive trials. In contrast, increases in stimulus-locked theta ICPS were associated with better performance on rewarded proactive trials. The pattern of results show that reward differentially impacted proactive and reactive control in adolescence, which may have implications for the increased risk-taking behaviors observed during adolescence.     

Traumatic brain injury and secondary attention-deficit/hyperactivity disorder in children and adolescents: the effect of reward on inhibitory control

Poor inhibitory control and abnormalities in responding to rewards are characteristic of the developmental or primary form of attention-deficit/hyperactivity disorder (P-ADHD). A secondary form of ADHD (S-ADHD) may occur as a consequence of childhood traumatic brain injury (TBI), but the similarities and differences between these two forms of ADHD have not been well characterized. To address these issues, we studied two inhibitory control tasks under different reward conditions in four groups of children and adolescents: TBI who did not exhibit S-ADHD, TBI who did exhibit S-ADHD, P-ADHD, and healthy controls. Participants with TBI exhibited poor cancellation inhibition relative to controls. Although reward facilitated both cancellation and restraint inhibition similarly across groups, poor performance persisted in the P-ADHD group, and participants with S-ADHD exhibited a selective deficit in cancellation inhibition.     

Altered brain morphology in boys with attention deficit hyperactivity disorder with and without comorbid conduct disorder/oppositional defiant disorder

About 50% of attention deficit hyperactivity disorder (ADHD) patients suffer from comorbidity with oppositional defiant disorder/conduct disorder (ODD/CD). Most previous studies on structural morphology did not differentiate between pure (ADHD‐only) and comorbid ADHD (ADHD+ODD/CD). Therefore, we aimed to investigate the structural profile of ADHD‐only versus ADHD+ODD/CD spanning the indices subcortical and cortical volume, cortical thickness, and surface area. We predicted a reduced total gray matter, striatal, and cerebellar volume in both patient groups and a reduced amygdalar and hippocampal volume for ADHD+ODD/CD. We also explored alterations in prefrontal volume, thickness, and surface area. We acquired structural images from an adolescent sample ranging from 11 to 17 years, matched with regard to age, pubertal status, and IQ—including 36 boys with ADHD‐only, 26 boys with ADHD+ODD/CD, and 30 typically developing (TD) boys. We analyzed structural data with FreeSurfer. We found reductions in total gray matter and total surface area for both patient groups. Boys with ADHD+ODD/CD had a thicker cortex than the other groups in a right rostral middle frontal cluster, which was related to stronger ODD/CD symptoms, even when controlling for ADHD symptoms. No group differences in local cortical volume or surface area emerged. We demonstrate the necessity to carefully differentiate between ADHD and ADHD+ODD/CD. The increased rostral middle frontal thickness might hint at a delayed adolescent cortical thinning in ADHD+ODD/CD. Patients with the double burden ADHD and ODD or CD seem to be even more affected than patients with pure ADHD.     

Response perseveration and sensitivity to reward and punishment in boys with oppositional defiant disorder

Abstract Response perseveration is the tendency to continue a response set for reward despite punishment. In the present study, response perseveration and sensitivity to reward and punishment were assessed in boys with oppositional defiant disorder (ODD). The study also examined the relation between punishment sensitivity and autonomic arousal. Nineteen ODD boys (mean age 9.8 years) and 20 normal control boys (NC) (mean age 9.7 years) were administered the door-opening task. In this task, the subject chooses either to open the next door or to stop playing; the opening of doors is initially rewarded and then increasingly punished. ODD boys opened more doors than NC boys. Following punishment, ODD boys took less time than NC boys before opening the next door, but did not differ from NC boys in time after reward. Mean skin conductance level was lower in ODD boys than in NC boys. The correlation coefficient between time after punishment and skin conductance level was moderately positive in the total sample. These results suggest that response perseveration in ODD boys is related to low punishment sensitivity and that skin conductance level is a marker of punishment sensitivity.     

Diagnostic consistency in assessing conduct disorder: an experiment on the effect of social context

The major objective of the diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders (see, e.g., the 4th ed., American Psychiatric Association, 1994) has been to achieve better diagnostic consistency. This has proved to be an elusive goal, because the diagnostic criteria and their rules for application can be ambiguous. This study mailed systematically varied case vignettes of conduct disorder to a nationally representative sample of 1,500 mental health clinicians in order to examine the effect of social context on diagnostic consistency. It found that consistency of diagnosis was modest and that it was affected by context and varied by profession.     

Personality trait differences in boys and girls with clinical or sub-clinical diagnoses of conduct disorder versus antisocial personality disorder

This study tested differences in personality traits measured by the Multidimensional Personality Questionnaire (MPQ) in a community sample of adolescents with definite or probable conduct disorder (CD) diagnoses that did not progress to a diagnosis of antisocial personality disorder (ASPD) by early adulthood (n=43), those with definite or probable ASPD that persisted into early adulthood (n=68), or controls with neither a CD nor an ASPD diagnosis (n=716) to examine whether antisocial behaviour disorders that differed in course were associated with differences in personality traits. As expected, boys and girls with ASPD were significantly different from controls on constraint, and those with ASPD were significantly lower on constraint than those with only CD. The results suggest that individual differences in certain personality traits may contribute to differences in the type of antisocial behaviour disorder that emerges and thereby to the course of antisocial behaviour.     

Probing reward function in posttraumatic stress disorder: expectancy and satisfaction with monetary gains and losses

BACKGROUND: Posttraumatic stress disorder (PTSD) may be associated with dysfunctional reward processing. The present study assessed for such dysfunction in both the expectancy and outcome phases of reward processing. METHODS: Male Vietnam veterans with (n=15) and without (n=11) combat-related PTSD were administered a wheel of fortune-type gambling task. Self-reported ratings of expectancy and satisfaction were collected respectively before and after each experience of monetary gain or loss. RESULTS: PTSD participants reported both lower expectancy of reward and lower satisfaction with reward when it was received. The latter result was manifest in a failure of PTSD participants to show the greater satisfaction that normally accompanies rewards received under conditions of low expectancy. CONCLUSION: These results suggest reward function impairment in PTSD related to expectancy, satisfaction, and the expectancy-satisfaction relationship.