Constructivist interpretation of attention-deficit hyperactivity disorder

Abstract

Despite the increasing frequency of the diagnosis of attention-deficit hyperactivity disorder, a critical review of the literature on the condition suggests difficulties with the assumptions that it can be reliably diagnosed, has neurobiological underpinnings, and is related to individual and contextual factors. These difficulties prompted us to attempt to develop a more adequate, constructivist conceptualization of the condition, which places emphasis on the role of optimal arousal modulation by the child in specific environments. Evidence supporting this model is cited, and the clinical implications of this constructivist reformulation are noted.     

Non-stimulant treatment of attention-deficit/hyperactivity disorder

Stimulants are a highly efficacious and safe treatment for attention-deficit/hyperactivity disorder (ADHD), with 75% to 90% of patients responding well if two different stimulants (amphetamine and methylphenidate) are used. Nonetheless, a subset of ADHD patients will either fail to respond to stimulants or have side effects that preclude their use (tics, severe loss of appetite, marked insomnia). For such patients, there are a number of non-stimulant agents that serve as second-line treatments. Tricyclic antidepressants (TCAs) are the most studied of these drugs. They are superior to placebo in the treatment of ADHD and may reduce abnormal movements in patients with ADHD/tic disorder. TCAs often produce side effects of sedation, dry mouth, and constipation. Bupropion is superior to placebo in the treatment of ADHD and has a more favorable side-effect profile than the TCAs. A new selective norepinephrine reuptake inhibitor, atomoxetine, has been shown to be efficacious in the treatment of ADHD and has recently received an approvable letter from the Food and Drug Administration. The a-agonists clonidine and guanfacine have also been used as alternative agents in ADHD, though the controlled data are more limited. A recent controlled clinical trial suggests a combination of methylphenidate and clonidine has advantages in the treatment of comorbid ADHD and tics over either medication alone. Clinical guidelines for each of these agents, as well as their use in combination with stimulants in comorbid conditions, will be discussed.     

Stimulus-dependent dopamine release in attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is related to an attenuated and dysfunctional dopamine system. Normally, a high extracellular dopamine level yields a tonic dopaminergic input that down-regulates stimuli-evoked phasic dopamine responses through autoreceptors. Abnormally low tonic extracellular dopamine in ADHD up-regulates the autoreceptors so that stimuli-evoked phasic dopamine is boosted. The authors propose that these boosted phasic responses yield hypersensitivity to environmental stimuli in ADHD. Stimuli evoking moderate brain arousal lead to well-functioning performance, whereas either too little or too much stimuli attenuate cognitive performance. Strong, salient stimuli may easily disrupt attention, whereas an environment with impoverished stimuli causes low arousal, which is typically compensated for by hyperactivity. Stochastic resonance is the phenomenon that makes a moderate noise facilitate stimulus discrimination and cognitive performance. Computational modeling shows that more noise is required for stochastic resonance to occur in dopamine-deprived neural systems in ADHD. This prediction is supported by empirical data.     

A psychoanalytic perspective on attention-deficit/hyperactivity disorder

Psychoanalysts have tended to view the diagnosis of AD/HD either with skepticism or as a contraindication to analytic treatment. The author reviews the history of this puzzling diagnostic entity, which is estimated to account for up to fifty percent of child referrals, and suggests that a psychoanalytic perspective on the underlying disturbance in ego functioning helps to clarify the nature of the symptom picture. Whatever the etiology, which may be compound, she suggests that psychoanalytic treatment, most often in conjunction with psychopharmacological therapy, can address the core disturbance in ego integration that creates the familiar triad of inattention, impulsivity, and hyperactivity.     

The predominantly inattentive subtype of attention-deficit/hyperactivity disorder

The predominantly inattentive (IN) subtype of attention-deficit/hyperactivity disorder (ADHD) is a recently defined condition that is often overlooked by professionals and is still not completely understood. Characterized by symptoms of inattentiveness, such as distractibility, failure to complete work, forgetfulness, and disorganization, the IN subtype differs from the more commonly recognized combined (CB) subtype of ADHD in that symptoms of hyperactivity and impulsivity are absent or minimal. Large-scale epidemiologic studies suggest that the IN subtype is at least as prevalent as the CB subtype, and is at least as likely to be associated with academic and/or social impairment. Diagnosis of the IN subtype, however, may be more challenging because in addition to inattentiveness, other symptoms, including learning problems, depression, and anxiety, may also present without externalizing behaviors. Several studies have shown that compared with the CB subtype, the IN subtype has a later age of onset and referral, a relatively larger proportion of affected females, and is much less likely to be associated with symptoms of oppositional defiant disorder or conduct disorder. Research is currently under way to examine the cognitive characteristics of the IN subtype and its genetic and neurobiologic underpinnings, as well as to evaluate the effectiveness of pharmacotherapy and other treatments.     

Gait control in children with attention-deficit/hyperactivity disorder

The current profile of gait control in children with ADHD is incomplete and predominately based on children walking forward at a self-selected pace. There are no studies of potential gait deficits in this clinical population when walking in different directions in combination with varying rates of stepping that are freely selected and entrained to an external stimulus. The purpose of the current study was to address this lack of information by assessing gait of children aged 7–17 years with (n = 17) and without (n = 26) ADHD. Participants walked forward and backward along an electronically instrumented carpet at a self-selected stepping rate and in synchrony to a metronome that dictated an increased and decreased stepping rate. Using repeated measures analysis of covariance (ANCOVA) to assess spatiotemporal gait parameters, results showed that children with ADHD exhibited a significantly exaggerated, toes ‘turned out,’ foot position for all walking conditions compared to typically developing children. When walking backward, children with ADHD produced an increased step width, higher stepping cadence, and increased velocity. Additionally, coefficient of variation ratios indicated that children with ADHD produced greater variability of velocity, cadence, and step time for all walking conditions, and greater variability for stride length when walking at an increased stepping rate. Results were interpreted in terms of clinical significance and practical ramifications that inform rehabilitation specialists in designing therapies that ameliorate the reported gait deficits.     

Neurocognitive functioning in adults with attention-deficit/hyperactivity disorder

The performance of nine adults with attention-deficit/hyperactivity disorder (ADHD) was compared with the performance of 23 normal controls on computerized measures of target orientation, sustained attention, encoding speed, and motor output/response organization to determine the nature of the neurocognitive deficits of adults with ADHD. While the groups' performances on measures of sustained attention and encoding speed did not differ, significant group differences were seen on a task that targeted motor output/response organization. These data suggest that the neurocognitive difficulties of ADHD adults are not related to a primary deficit in sustained attentional functioning. Rather, the deficient information processing in ADHD adults is related to difficulties with motor output/response organization.     

Quality of life of adolescent males with attention-deficit hyperactivity disorder

Most psychosocial research on attention-deficit/hyperactivity disorder (ADHD) has focused on deficits in school, family, or behavioral functioning without incorporating perceived quality of life (QoL) or the adolescents' perspective. The Youth Quality of Life Instrument--Research Version (YQOL-R), was used to assess self-perceived QoL in a community sample of adolescents aged 11-18 years. Fifty-five adolescent males with a clinical diagnosis of ADHD were compared to a group of 107 adolescents with no chronic conditions (NCC) and a group of 52 adolescents with mobility impairments (MI). The adolescents with ADHD reported significantly lower perceived QoL scores, particularly in the Self and Relationship domains, than the NCC group. Their scores were similar to those from the group with MI, a group previously shown to have a substandard QoL. Interventions to improve self-esteem and social interactions might use QoL outcomes in evaluating effectiveness.     

A Rational-Emotive Treatment program with conduct disorder and attention-deficit hyperactivity disorder adolescents

This study investigated the effects of a 12-week treatment program, based on Rational-Emotive Therapy, with conduct disorder (CD) and attention-deficit hyperactivity disorder (ADHD) adolescents. Two independent homogeneous CD (N=12) and ADHD (N=12) groups were selected on the basis of the DSM-111-R and use of methylphenidate. The dependent variables were irrational thinking, depression, and anger. Lecture, discussion, and theYou Can Do It!Motivational Program video were used in the treatment intervention. Discriminant function analysis of pretest scores revealed that 96% of the students were correctly classified (CD=100%, ADHD=92%). Multivariate analysis of pre-posttest scores revealed that the CD group significantly changed on all dependent variables, while no significant differences were found with the ADHD group. A comparison of posttest scores on the measure of irrational thinking revealed that the CD group accepted responsibility for their upsetness and were more willing to change than the ADHD group. The results of the study are interpreted in terms of the distinguishing characteristics of each group.G. Barry Morris Ph.D., is Director of the Canadian Institute for Rational-Emotive Therapy. He is a Fellow and training supervisor in Rational-Emotive Therapy, a professor at the University of Saskatchewan, a licensed psychologist, and is engaged in private practice.     

Eating pathology among adolescent girls with attention-deficit/hyperactivity disorder

The authors investigated prospectively assessed eating pathology (body image dissatisfaction and bulimia nervosa symptoms) among an ethnically and socioeconomically diverse sample of adolescent girls with attention-deficit/hyperactivity disorder-combined type (ADHD-C; n=93), ADHD-inattentive type (ADHD-I; n=47), and a comparison group (n=88). The sample, initially ages 6-12 years, participated in a 5-year longitudinal study (92% retention rate). After statistical control of relevant covariates, girls with ADHD-C at baseline showed more eating pathology at follow-up than did comparison girls; girls with ADHD-I were intermediate between these two groups. Baseline impulsivity symptoms, as opposed to hyperactivity and inattention, best predicted adolescent eating pathology. With statistical control of ADHD, baseline peer rejection and parent- child relationship problems also predicted adolescent eating pathology. The association between punitive parenting in childhood and pathological eating behaviors in adolescence was stronger for girls with ADHD than for comparison girls. Results are discussed in terms of the expansion of longitudinal research on ADHD to include female-relevant domains of impairment, such as eating pathology.     

Processing affective stimuli in children with attention-deficit hyperactivity disorder.

Neuropsychological investigations have suggested a contribution of right hemisphere dysfunction in attention-deficit hyperactivity disorder (ADHD). Right hemisphere dysfunction has been implicated in deficits of attention, motor impersistence, and processing emotion-laden stimuli. The current study investigated the ability of ADHD children to perceive emotional stimuli in the form of facial expressions and speech intonation. The subjects consisted of 37 ADHD and 37 control children aged 7 to 12 years. ANCOVA analysis indicated that ADHD children demonstrate mild-to-moderate deficits in the perception of affect. Furthermore, deficits in attention may contribute to inaccurate or incomplete encoding of stimulus properties. The results lend tentative support for the notion that the right cerebral hemisphere may play a critical role in ADHD.     

Cognitive inhibition and working memory in attention-deficit/hyperactivity disorder

Studies of cognitive control in attention-deficit/hyperactivity disorder (ADHD) have emphasized the ability to suppress motor responses (i.e., behavioral inhibition) rather than the ability to actively suppress prepotent mental representations (i.e., cognitive inhibition). Further, working memory deficits are suspected in ADHD, yet their distinction from cognitive inhibition is unclear. Two hundred and eighty-eight adolescent and adult participants, 115 of whom met criteria for ADHD and 173 of whom were for non-ADHD comparison, completed a sentence processing task that required the suppression of an incorrect interpretation and a working memory task. The results failed to support cognitive inhibition problems in ADHD. Moreover, the ability to reanalyze sentences with a temporary misinterpretation was at least partially related to working memory performance. The results challenge a unitary inhibition problem in ADHD and suggest inhibition problems do not extend to cognitive suppression in this age range.     

Diminished testing benefits in young adults with attention-deficit hyperactivity disorder

Memory retrieval has been shown to enhance the long-term retention of tested material; however, recent research suggests that limiting attention during retrieval can decrease the benefits of testing memory. The present study examined whether testing benefits are reduced in young adults with attention-deficit hyperactivity disorder (ADHD). College students with and without ADHD read three short prose passages, each followed by a free recall test, a restudy period or a distractor task. Two days later participants recalled the passages. Although participants without ADHD did not show a significant benefit of testing over restudying, testing did produce recall benefits relative to not taking a test. These testing benefits were diminished in participants with ADHD, who did not show any advantage of testing over either restudying or no test. The absence of testing benefits in the ADHD group is likely due in part to decreased recall on the initial test. These findings have implications for improving educational practices among individuals with ADHD and also speak to the need to examine individual differences in the effectiveness of testing as a learning strategy.     

Parenting in mothers with and without attention-deficit/hyperactivity disorder

The authors examined the impact of maternal attention-deficit/hyperactivity disorder (ADHD) on parenting behaviors. Sixty mothers between the ages of 31 and 50 with (n = 30) and without (n = 30) ADHD and their 8- to 14-year-old children with ADHD completed self-report and laboratory measures of monitoring of child behavior, consistency in parenting, and parenting problem-solving abilities. These parenting behaviors were selected because of their established links to the development of child behavior problems. As predicted, mothers with ADHD were found to be poorer at monitoring child behavior and less consistent disciplinarians compared with mothers without ADHD. There was some evidence to support the prediction that mothers with ADHD were less effective at problem solving about childrearing issues than control mothers. The differences between the 2 groups of mothers persisted after child oppositional and conduct-disordered behavior were controlled. These results indicate that parenting is an area of functioning that requires more attention in adult ADHD research.     

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.     

Predictors of physical aggression in children with attention-deficit/hyperactivity disorder

The present investigation examined factors that predict physical aggression in children with attention-deficit/hyperactivity disorder (ADHD). Stepwise, multiple regression-analyses were used to examine predictors of children's physical aggression as rated by parents at a 1-year follow-up point and by teachers at both 1- and 2-year follow-up points. Early parent and teacher ratings of verbal aggression (ie, cursing, teasing, and threatening) accounted for the greatest proportion of the variance in physical aggression ratings obtained at follow-up. None of the other predictor variables, including early ratings of physical aggression and ADHD behaviors, contributed significant additional variance beyond that accounted for by early verbal aggression ratings. Temporal and cross-informant analyses revealed that the relationship between verbal aggression and later physical aggression was situation-specific for teacher ratings but not parent ratings. Although physical aggression may emerge early in development, these data suggest that verbal aggression represents a stable, temperamental characteristic that may be of greater value than early physical aggression for predicting later physically aggressive acts.