Covert antisocial behavior in boys with attention-deficit hyperactivity disorder: external validation and effects of methylphenidate.

Covert antisocial behaviors such as stealing, destroying property, and cheating carry high risk for delinquency. An individual laboratory setting was devised in which youngsters could take desired objects and use answer keys to assist with worksheets. Twenty-two boys with attention-deficit hyperactivity disorder (ADHD) and 22 comparison boys were observed on two occasions, with the ADHD Ss receiving a methylphenidate-placebo crossover. Laboratory stealing and property destruction were positively correlated with maternal and staff ratings of parallel behaviors. Methylphenidate resulted in significant reductions of these acts, but it also effected an increase in cheating, presumably because of its enhancement of task involvement. The generalizability of the laboratory findings, actions of stimulants in this domain, and the ethics of experimental investigations of covert antisocial behavior are discussed.     

Trends in studies of prosocial behavior

The present article provides an analysis of past trends and recent developments in studies of prosocial behavior which began in the latter half of the 1960s. Particular emphasis is placed on studies relating to the subsequent bystander effect, the development of decision-making models incorporating interactions of various factors, empathy, perspective-taking, and prosocial moral judgment as an important mediating factor in motivation, including the viewpoint of self-perception. The article concludes by considering the relevance of studies of prosocial behavior to psychology at large and the directions such studies might take in the future.     

The effects of role playing on prosocial behavior in preschool children]

The purpose was to examine the effects of two types of role-playing experience on prosocial behavior in preschool children. Subjects were 72 6-year-olds. In the Empathy role-playing (E), each pair of children enacted alternately a victim and an eyewitness using a glove puppet, in which the emphasis was only on empathizing with the victim. In the Empathy and Helping role-playing (EH), they enacted alternately a victim and a helper, in which the emphasis was on empathizing and helping a victim. In the Control role-playing (C), they played roles alternately of a customer and a salesman in a grocery store. All children were assessed as for helping and sharing behaviors for a real victim before and after the role playing session. In the comparison between pre- and post-tests for helping behavior. All groups (C, E, EH) increased helping tendency, but only in EH group the proportion of subjects, whose attitude changed from helper to non-helper. As for sharing behavior, all three groups increased the number of sharing significantly in the post-test.     

Effects of methylphenidate and expectancy on children with ADHD: behavior, academic performance, and attributions in a summer treatment program and regular classroom settings

Pharmacological and expectancy effects of 0.3 mg/kg methylphenidate on the behavior and attributions of boys with attention-deficit/hyperactivity disorder were evaluated. In a within-subject, balanced-placebo design, 136 boys received 4 medication-expectancy conditions. Attributions for success and failure on a daily report card were gathered. Assessments took place within the setting of a summer treatment program and were repeated in boys' regular classrooms. Expectancy did not affect the boys' behavior; only active medication improved their behavior. Boys attributed their success to their effort and ability and attributed failure to task difficulty and the pill, regardless of medication and expectancy. Results were generally equivalent across the two settings; where there were differences, beneficial effects of medication were more apparent in the school setting. The findings were unaffected by individual-difference factors.     

Which boys respond to stimulant medication? A controlled trial of methylphenidate in boys with disruptive behaviour

Thirty-eight boys, referred for psychiatric treatment because of serious problems of behaviour, underwent a double-blind, placebo-controlled, crossover trial of methylphenidate and placebo. Methylphenidate was an effective treatment over a 3-week period. A good response to methylphenidate was predicted by higher levels of inattentive and restless behaviour, impaired performance on tests of attention, clumsiness, younger age and by the absence of symptoms of overt emotional disorder. DSM-III and ICD-9 diagnoses of 'hyperactivity' were not good predictors. The results support the validity of a construct of hyperactivity in describing childhood psychopathology, but emphasize the need for a refinement of diagnostic criteria.     

Testosterone dependent effects of methylphenidate on social investigatory behavior of the rat

Previous work suggested a sex difference in social investigatory behavior of a novel conspecific during acute exposure to methylphenidate. In contrast to caffeine, which has been observed to increase social investigatory behavior only in males, methylphenidate decreased social investigatory behavior only in females. Testosterone-treated females were comparable to males and were unaffected by methylphenidate. Castrated males were comparable to females in their sensitivity to methylphenidate. Like caffeine, methylphenidate increased locomotor activity in both males and females, suggesting that drug effects on social investigation cannot be attributed to a nonspecific stimulant effect. The combined results reveal a sex-related interaction of circulating testosterone with acute methylphendiate exposure. Interpretations are discussed including the behavioral contrast following exposure to methylphenidate or to caffeine.     

Behavior phenotype of FG syndrome: cognition, personality, and behavior in eleven affected boys

In this study we examined several behavioral, personality, and cognitive characteristics of boys with FG syndrome. We confirmed high rates of attention and activity level problems, which were described previously. Nine of the 11 patients met criteria for attention deficit/hyperactivity disorder. The boys did not manifest autistic behavior, and none met criteria for an autism spectrum disorder, though their parents reported substantial repetitive behavior. The personalities of the participants often were described as friendly, good-natured, and cheerful, but they did not differ empirically on a standardized measure of personality structure from typically developing comparison children, even after controlling for the effects of IQ. Specifically, higher rates of agreeableness and extraversion were not confirmed, though these constructs do not correspond perfectly with the traits of affability and gregariousness described in earlier published case studies of FG syndrome. In terms of neuropsychological assessment, the boys had relatively less developed language, fine motor, and executive function skills, and visual-spatial abilities were a relative strength. Limitations and suggestions for future research are discussed.     

Aggressive behavior in hypertensive and normotensive rat strains

Shock induced fighting, mouse killing, and jump thresholds were measured in gentically hypertensive or hypertensive-prone rat strains and in normotensive and surgically induced (renal) hypertensive rats. Differences in levels of shock induced agression and jump thresholds were observed, but were not a direct effect of hypertension and appeared to be traits genetically separate from the susceptibility to hypertension.     

Differential dose effects of central CRF and effects of CRF astressin on pig behavior

The elevation of central corticotropin releasing factor (CRF) causes an increase in behavioral activity, including increases in overall activity and oral/nasal/facial (ONF) chewing-rooting-rubbing behaviors in the pig and similar behaviors in other species. This study detailed changes in the frequency, duration and sequences of behaviors after central administration of vehicle or porcine CRF (pCRF at 0.5, 5.0, 50 and 150 microg). A sequential analysis described the complex behaviors induced in a dose-dependent fashion by central pCRF. The frequency and duration of ONF behaviors were significantly increased among pigs receiving 50 microg of pCRF. For behaviors such as ONF, 50 microg represented a breakpoint at which the frequency and duration of single behaviors increased. Pigs receiving 50 microg of pCRF were considerably more active and exhibited more ONF behaviors than did pigs receiving lower doses. The highly sensitive sequential analysis revealed that very low doses of central pCRF induced subtle changes in sequences of behaviors. Low doses of central pCRF (0.5 microg) induced fear-related behavioral sequences that included ONF behaviors alternating with periods of inactivity. Central injection of astressin, a CRF receptor antagonist, blocked many, but not all, of CRF-induced behaviors. Compared with saline-injected control pigs, central pCRF increased general activity, ONF, fear-related freezing and sham chewing behaviors. When pCRF was given following astressin, fear-related freezing behaviors were not different compared with pigs receiving saline. However, pigs given astressin plus pCRF showed elevated sham chewing compared with saline-injected control pigs, as did pigs receiving intracerebroventricular (ICV) pCRF. These data indicate that central pCRF activates brain mechanisms associated with hyperactivity, ONF and fear-related behaviors, whereas other behaviors induced by pCRF may be nonspecifically mediated by CRF. Astressin antagonized some, but not all, pCRF-induced behaviors. This model represents the induction of hyperactivity and stereotyped behaviors, which may represent a new model for the study of mania or obsessive-compulsive behaviors.     

The role of attentional processes in children's prosocial behavior with peers: attention shifting and emotion

This study evaluated the role of attentional shifting in children's prosocial behavior with peers. Participants were 27 aggressive/rejected and 27 nonaggressive/popular kindergarten and first grade boys and girls. Children's ability to shift attention from one affective state to another was assessed during: (a) a computerized task that required shifting attention between different affective events (i.e., the Children's Attentional Shifting Task, CAST) and (b) an analogue entry task with unacquainted peers. Children's latency for sharing with peers was assessed after they experienced failure during the entry task. Aggressive/rejected children had significant difficulty shifting attention from negative to positive affect during the CAST and were slower to share after experiencing entry failure. In general, aggressive/rejected children were less able to regulate their behavior effectively after experiencing social failure. Girls, regardless of status, had less difficulty than boys shifting attention from one affective state to another during the CAST. In addition, children's social status/aggressiveness, their ability to regulate emotional behavior after social failure and to shift attention effectively on the CAST predicted approximately 31% of the variance in their latency to share. These findings suggest that the ability to shift attention between different affective states plays a significant role in children's prosocial behavior with peers.     

Steroidal control of male hamster sexual behavior in Me and MPOA: effects of androgen dose and tamoxifen

Steroids stimulate male sexual behavior through interconnected limbic nuclei, including the medial amygdala (Me) and medial preoptic area (MPOA). Although Me and MPOA each can transduce hormonal cues to induce sexual activity in castrated male hamsters, simultaneous stimulation of Me and MPOA fails to amplify mating. The present study extends our investigations of redundancy in the hormonal control of mating by testing the behavioral effects of (1) increasing steroid dose in a single brain region or (2) locally blocking steroid action with an estrogen antagonist. In Experiment 1, sexually experienced castrates received a single testosterone implant in Me, bilateral testosterone implants, or a single implant of a highly potent androgen, 7a-methyl-19-nortestosterone (MENT). These treatments stimulated mating behavior: 2 weeks after surgery, mounting was observed in > or =50% of the males in each group. In Experiment 2, castrated males received intracerebral implants of the estrogen antagonist tamoxifen in Me or MPOA, combined with systemic testosterone replacement. Tamoxifen in MPOA had minimal effects on the recovery of mating behavior. With tamoxifen in Me, mounts and intromissions were significantly reduced 18 days after surgery. However, the percent of males in each group that expressed mounts, intromissions or ejaculations was not different. Thus, in Experiment 1, increasing the amount of steroid does not amplify mating. Likewise, local blockade of hormone action in Experiment 2 does not prevent behavior. These findings support the concept that steroids are largely permissive for male sex behavior. Steroid stimulation of either Me or MPOA is sufficient for sexual activity. Conversely, neither Me nor MPOA has an absolute requirement for hormones to facilitate expression of mating.     

Effects of methylphenidate on quantitative EEG of boys with attention-deficit hyperactivity disorder in continuous performance test

The purpose of this study was to investigate the effects of methylphenidate, a psychostimulant, on quantitative electroencephalography (QEEG) during the continuous performance test (CPT) in boys with attention-deficit hyperactivity disorder (ADHD). The QEEG was obtained from 20 boys with ADHD. The amplitudes of 4 bands (alpha, beta, delta, and theta) in the QEEG, as well as the theta /beta ratio, before and after the administration of methylphenidate were compared during both the resting and CPT states. Methylphenidate induced a significant increase of alpha activities in both the right and left frontal and occipital areas, an increase of beta activities in almost all areas except for the temporal region, a decrease of theta activities in both the occipital and right temporo-parietal areas, a mild decrease of delta activities in the occipito-parietal areas, and an increase of the theta/beta ratio in the right frontal and parieto-occipital, and left temporal areas during the CPT state. No significant QEEG changes were induced by the administration of methylphenidate in the resting state. These data suggest that methylphenidate has greater electrophysiological influences on the cerebral topographical activities during the performance of attentional tasks, as compared to the resting state, in boys with ADHD.     

Utilization behavior in boys with ADHD: a test of Barkley's theory

Barkley's (1997) comprehensive theory of attention deficit hyperactivity disorder (ADHD) predicts that affected children express frontal lobe related impairments, including expression of utilization behavior-the appropriate use of an object in an inappropriate context. Nineteen boys with and 20 without ADHD were exposed to a series of utilitarian (potentially utilization-inducing) and neutral objects. Boys in the ADHD group exhibited more utilization behavior and did so more quickly than boys in the control group; engagement with utilitarian objects and tendencies to do so quickly best predicted ADHD and control group membership. Beyond utilization behavior distinctions, general impulsivity differences were seen between boys with ADHD and control group counterparts, but these were less pronounced than the utilization behavior differences. Results offer support for utilization behavior's place in Barkley's theory.