Attention deficit/hyperactivity disorder children with a 7-repeat allele of the dopamine receptor D4 gene have extreme behavior but normal performance on critical neuropsychological tests of attention.
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An association of the dopamine receptor D4 (DRD4) gene located on chromosome 11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated and replicated by multiple investigators. A specific allele [the 7-repeat of a 48-bp variable number of tandem repeats (VNTR) in exon 3] has been proposed as an etiological factor in attentional deficits manifested in some children diagnosed with this disorder. In the current study, we evaluated ADHD subgroups defined by the presence or absence of the 7-repeat allele of the DRD4 gene, using neuropsychological tests with reaction time measures designed to probe attentional networks with neuroanatomical foci in D4-rich brain regions. Despite the same severity of symptoms on parent and teacher ratings for the ADHD subgroups, the average reaction times of the 7-present subgroup showed normal speed and variability of response whereas the average reaction times of the 7-absent subgroup showed the expected abnormalities (slow and variable responses). This was opposite the primary prediction of the study. The 7-present subgroup seemed to be free of some of the neuropsychological abnormalities thought to characterize ADHD. (+info)
Treatment of attention-deficit/hyperactivity disorder.
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OBJECTIVES: To determine (a) the long-term and short-term effectiveness and safety of pharmacological and nonpharmacological interventions for attention-deficit/hyperactivity disorder (ADHD) in children and adults and (b) whether combined interventions are more effective than individual interventions. SEARCH STRATEGY: MEDLINE (from 1966), CINAHL (from 1982), HEALTHStar (from 1975), PsycINFO (from 1984), EMBASE (from 1984), and the Cochrane Library searches were completed in November 1997. Reference lists of eligible studies and files of members of the research team and partner organizations were also searched. SELECTION CRITERIA: Studies were selected if they focused on the treatment of ADHD in humans and were published in any language as a full report in peer-reviewed journals. Studies including conditions other than ADHD were reported if separate subgroup analyses for patients with ADHD were provided. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data for 41 variables on general characteristics, along with detailed information on interventions, outcomes, and tests. Differences were resolved by consensus or by a third researcher. Studies were not combined quantitatively because the quality of reporting was low and heterogeneity existed across outcome measures and tests. MAIN RESULTS: Seventy-eight studies (77 randomized controlled trials) met the inclusion criteria. Twenty-three studies compared drugs and showed few, if any, differences among methylphenidate (MPH), dextroamphetamine (DEX), and pemoline; studies comparing stimulants with tricyclic antidepressants (2) were inconclusive. Six studies compared drugs with nondrug interventions and showed consistently that stimulants, particularly MPH, may be more effective than nonpharmacological interventions. Twenty studies compared combination therapies with a stimulant or a nondrug intervention alone; no additional beneficial effects for combination therapies were shown. Nine studies compared tricyclic antidepressants with placebo and showed that desipramine may be more effective than placebo; no consistent effect was shown for imipramine. Fourteen studies (13 in school children and 1 in adults) evaluated long-term therapy (> or = 12 weeks) and showed a trend to general improvement regardless of treatment, but the length of followup was inadequate. MPH may reduce behavioral disturbance in children with ADHD while it is taken. Academic performance does not appear to be improved with stimulants. Twelve studies evaluated treatment in adults with ADHD. For MPH vs. placebo, the results were contradictory. Antidepressants may be effective in adults, but no beneficial effect was seen with pemoline, nicotine, or phenylalanine compared with placebo. Thirty-two reports (29 studies) evaluated adverse effects of drug therapy; many of the side effects associated with stimulant use appear to be relatively mild and of short duration and to respond to dosing or timing adjustments. Data are inadequate on the long-term effects and severity of adverse effects of most interventions. CONCLUSIONS: This report describes rigorous systematic reviews on the treatment of ADHD, ready for incorporation into evidence-based clinical practice guidelines or performance measures. The report also provides a detailed description of the many limitations of the evidence available and provides recommendations to fill existing knowledge gaps. Studies on ADHD have low reporting quality, methodological flaws, and heterogeneity across outcome measures and tests. A detailed description is included of the many limitations of the available evidence plus recommendations to fill existing knowledge gaps. Fulfilling such knowledge gaps will not be easy and will require genuine collaboration among decisionmakers. (+info)
Addiction: part II. Identification and management of the drug-seeking patient.
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The medications most often implicated in prescription drug abuse are opioid analgesics, sedative-hypnotics and stimulants. Patients with acute or chronic pain, anxiety disorders and attention-deficit disorder are at increased risk of addiction comorbidity. It is important to ask patients about their substance-use history, including alcohol, illicit drugs and prescription drugs. Patients who abuse prescription drugs may exhibit certain patterns, such as escalating use, drug-seeking behavior and doctor shopping. A basic clinical survival skill in situations in which patients exert pressure on the physician to obtain a prescription drug is to say "no" and stick with it. Physicians who overprescribe can be characterized by the four "Ds"-dated, duped, dishonest and disabled. Maintaining a current knowledge base, documenting the decisions that guide the treatment process and seeking consultation are important risk-management strategies that improve clinical care and outcomes. (+info)
Adult onset tic disorders.
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BACKGROUND: Tic disorders presenting during adulthood have infrequently been described in the medical literature. Most reports depict adult onset secondary tic disorders caused by trauma, encephalitis, and other acquired conditions. Only rare reports describe idiopathic adult onset tic disorders, and most of these cases represent recurrent childhood tic disorders. OBJECTIVE: To describe a large series of patients with tic disorders presenting during adulthood, to compare clinical characteristics between groups of patients, and to call attention to this potentially disabling and underrecognised neurological disorder. METHODS: Using a computerised database, all patients with tic disorders who presented between 1988 and 1998 to the movement disorders clinic at Columbia-Presbyterian Medical Center after the age of 21 were identified. Patients' charts were retrospectively reviewed for demographic information, age of onset of tics, tic phenomenology, distribution, the presence of premonitory sensory symptoms and tic suppressibility, family history, and associated psychiatric features. These patients' videotapes were reviewed for diagnostic confirmation and information was obtained about disability, course, and response to treatment in a structured follow up interview. RESULTS: Of 411 patients with tic disorders in the database, 22 patients presented for the first time with tic disorders after the age of 21. In nine patients, detailed questioning disclosed a history of previous childhood transient tic disorder, but in 13 patients, the adult onset tic disorder was new. Among the new onset cases, six patients developed tics in relation to an external trigger, and could be considered to have secondary tic disorders. The remaining patients had idiopathic tic disorders. Comparing adult patients with recurrent childhood tics and those with new onset adult tics, the appearance of the tic disorder, the course and prognosis, the family history of tic disorder, and the prevalence of obsessive-compulsive disorder were found to be similar. Adults with new onset tics were more likely to have a symptomatic or secondary tic disorder, which in this series was caused by infection, trauma, cocaine use, and neuroleptic exposure. CONCLUSIONS: Adult onset tic disorders represent an underrecognised condition that is more common than generally appreciated or reported. The clinical characteristics of adults newly presenting to a movement disorder clinic with tic disorders are reviewed, analysed, and discussed in detail. Clinical evidence supports the concept that tic disorders in adults are part of a range that includes childhood onset tic disorders and Tourette's syndrome. (+info)
Parallels between attention deficit hyperactivity disorder and behavioral deficits produced by neurotoxic exposure in monkeys.
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Attention deficit hyperactivity disorder (ADHD) is a disability that affects between 3 and 7% of children, with a significant number of individuals continuing to be affected into adolescence and adulthood. ADHD is characterized in part by an inability to organize complex sequences of behavior, to persist in the face of distracting stimuli, and to respond appropriately to the consequences of past behavior. There are some parallels between the features of ADHD and the behavior of monkeys exposed developmentally to lead or polychlorinated biphenyls (PCBs), as evidenced by research from our laboratory. Both lead and PCB exposure produce deficits on discrimination reversal and spatial delayed alternation performance; treated monkeys exhibit deficits in their ability to change an already established response strategy and inhibit inappropriate responses. Monkeys exposed developmentally to lead or PCBs also perform differently from control monkeys on a fixed interval schedule of reinforcement, which requires the temporal organization of behavior using only internal cues. Whereas the etiology of ADHD is multifactorial, the possibility that neurotoxic agents in the environment contribute to the incidence of ADHD warrants attention. (+info)
A procedure to teach self-control to children with attention deficit hyperactivity disorder.
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This study examined the use of a progressive delay procedure combined with verbal mediation to teach self-control to children with attention deficit disorder. Results showed that when participants were initially given the choice between an immediate smaller reinforcer and a larger delayed reinforcer, all participants chose the smaller reinforcer. When slight delays to obtain a larger reinforcer were instated in conjunction with intervening verbal activity, all participants demonstrated self-control regardless of the content of the verbal activity. (+info)
Early attention problems and children's reading achievement: a longitudinal investigation. The Conduct Problems Prevention Research Group.
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OBJECTIVES: To determine whether attention problems predict the development of reading difficulties and examine whether screening for attention problems could be of practical value in identifying children at risk for reading underachievement. METHOD: Three hundred eighty-seven children were monitored from kindergarten through fifth grade. Standardized assessments of attention problems and reading achievement were conducted at multiple time points. RESULTS: Attention problems predicted reading achievement even after controlling for prior reading achievement, IQ, and other behavioral difficulties. Inattentive first graders with normal reading scores after kindergarten were at risk for poor reading outcomes. CONCLUSIONS: Attention problems play an important role in the development of reading difficulties for some children, and screening for attention problems may help identify children at risk for reading difficulties. (+info)
Prevalence of attention-deficit hyperactivity disorders in students. Comparison between DSM-IV and neuropsychological criteria.
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Attention-deficit hyperactivity disorder (ADHD) is a common childhood condition, recognized as an important social-medical problem. The syndrome is characterized by motor system, perception, cognition and behavioral disturbances, compromising the learning of children with adequate intellectual potential. To investigate its prevalence in first grade pupils 484 children with DSM-IV diagnostic criteria and neuropsychological criteria were examined. The prevalence of ADHD was 18% when the diagnosis was made using DSM-IV criteria; 3.5% when neuropsychological criteria was used, including, in addition to behavioral and psychometric aspects, a discrepancy in the evolutionary neurological examination, and 3.9% when motor persistence was taken into account. The prevalence of ADHD was higher among older children (92.4 months) only when DSM-IV criteria were used. We conclude that the use of DSM-IV criteria probably overestimates the prevalence of ADHD, since it detects another behavioral disorders. In this context, they may be useful as screening, since they have adequate pre-testing performance. (+info)