Screening for attention-deficit/hyperactivity disorder in adult inpatients with psychiatric disorders

The purpose was to assess the effectiveness of the adult ADHD Module from the MINI International Neuropsychiatric Interview (MINI) and the Conners' Adult ADHD Rating Scales: Screening Version DSM-IV ADHD Symptoms Total Scale (CAARS-S:SV) in screening for attention-deficit/hyperactivity (ADHD) disorder in patients hospitalized for other psychiatric disorders. Assessment measures were administered to 55 (50%) female and 55 (50%) male adult (>18 yr. old) inpatients. Only six (5%) of the 110 inpatients had been diagnosed with comorbid ADHD according to medical charts. In contrast, 55 (50%) patients met criteria for ADHD according to the MINI, and 39 (36%) patients met criteria on the CAARS-S:SV. The higher rates of prevalence for the MINI and the CAARS-S:SV were attributable to symptom criteria for ADHD being similar to those shared with comorbid disorders.     

Response timing variability: coherence of kinematic and EMG parameters

A detailed kinematic and electromyographic (EMG) analysis of single degree of freedom timing responses is reported to (a) determine the coherence of kinematic and EMG variability to the reduced timing error variability exhibited with amplitude increments within a given criterion movement time and (b) understand the temporal organization of various movement parameters in simple responses. The data reveal that the variability of kinematic (time to peak acceleration, duration of acceleration phase, time to peak deceleration) and EMG (duration of agonist burst, duration of antagonist burst, time to antagonist burst) timing parameters decreased with increments of average velocity in a manner consistent with the variable timing error. In addition, the coefficient of variation for peak acceleration, peak deceleration, and integrated EMG of the agonist burst followed the same trend. Increasing average movement velocity also led to decreases in premotor and motor reaction times. Overall, the findings suggest a strong coherence between the variability of response outcome, kinematic, and EMG parameters.     

Executive function deficits in autism spectrum disorders and attention-deficit/hyperactivity disorder: examining profiles across domains and ages

Deficits in 'executive function' (EF) are characteristic of several clinical disorders, most notably Autism Spectrum Disorders (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD). In this study, age- and IQ-matched groups with ASD, ADHD, or typical development (TD) were compared on a battery of EF tasks tapping three core domains: response selection/inhibition, flexibility, and planning/working memory. Relations between EF, age and everyday difficulties (rated by parents and teachers) were also examined. Both clinical groups showed significant EF impairments compared with TD peers. The ADHD group showed greater inhibitory problems on a Go-no-Go task, while the ASD group was significantly worse on response selection/monitoring in a cognitive estimates task. Age-related improvements were clearer in ASD and TD than in ADHD. At older (but not younger) ages, the ASD group outperformed the ADHD group, performing as well as the TD group on many EF measures. EF scores were related to specific aspects of communicative and social adaptation, and negatively correlated with hyperactivity in ASD and TD. Within the present groups, the overall findings suggested less severe and persistent EF deficits in ASD (including Asperger Syndrome) than in ADHD.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

Trait mechanisms in youth with and without attention-deficit/hyperactivity disorder

Relations of temperament and personality traits within children and adolescents with ADHD and non-ADHD controls were examined. A two-process structure was hypothesized involving top-down effortful and bottom-up reactive response tendencies. Top-down processes were hypothesized to relate to inattentive ADHD symptoms, whereas bottom-up processes were hypothesized to relate to hyperactive–impulsive ADHD symptoms. Each hypothesis was tested in a sample of 179 children age 7–13 (113 boys; 107 ADHD) and then replicated in 184 adolescents age 14–17 (109 boys; 87 ADHD). All families completed a multistage diagnostic process. Youth completed laboratory measures of cognitive control, and parents completed trait ratings. Traits examined in the current study included effortful control, reactive control, resiliency, negative emotionality, neuroticism, extraversion, openness, agreeableness, and conscientiousness. Correlational relations among traits were inconclusive, but external correlations with cognitive tasks and ADHD symptoms were interpretable within the hypothesized two-process framework. Results provide partial support for a distinction between effortful and reactive traits and suggest this distinction is useful in relation to understanding ADHD.     

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.