Non-stimulant treatments for ADHD

Viloxazine for the Treatment of Attention Deficit Hyperactivity Disorder

Purpose of Review

Attention deficit hyperactivity disorder (ADHD) is a widely diagnosed neurodevelopmental disorder giving rise to symptoms of hyperactivity, impulsivity, and inattentiveness that can impair daily functioning. Stimulants, such as methylphenidate and amphetamines, are the mainstay of treatment for ADHD. However, nonstimulant drugs such as viloxazine, atomoxetine, guanfacine, and clonidine are becoming more popular due to minimal adverse effects when compared to stimulants.

Recent Findings

Viloxazine is a selective norepinephrine reuptake inhibitor (NRI) originally used to treat depression in adults with activity in both the noradrenergic as well as serotonergic pathways. Studies have demonstrated its efficacy for its use in the treatment of ADHD. Unlike stimulants, viloxazine has a decreased chance of substance abuse, drug dependance, and withdrawal symptoms upon the cessation of therapy. Additionally, dopamine levels in the nucleus accumbens after treatment with viloxazine are elevated considerably less in comparison with traditional stimulant ADHD treatments. Viloxazine provides an alternative, nonstimulant approach to treating ADHD.

Summary

Viloxazine is a recently approved, non-stimulant medication functions by inhibiting the uptake of norepinephrine which has been seen to be decreased in patients with ADHD. When patients do not respond to first-line stimulants, cannot tolerate the side effects, or have contraindications to stimulants, viloxazine may be a nonstimulant option offering patients an increasing arsenal of medications to treat ADHD.

Personalization of pharmacological treatments for ADHD: Why it is advisable and possible options to achieve it

Abstract:

Attention-deficit hyperactivity disorder is a neurodevelopmental disorder diagnosed primarily in children, although it is also present in adults. Patients present inattention, impulsivity, and hyperactivity symptoms that create difficulties in their daily lives. Pharmacological treatment with stimulants or non-stimulants is used most commonly to reduce ADHD symptoms. Although generally effective and safe, pharmacological treatments have different effects among patients, including lack of response and adverse reactions. The reasons for these differences are not fully understood, but they may derive from the highly diverse etiology of ADHD. Strategies to guide optimal pharmacological treatment selection on the basis of individual patients’ physiological markers are being developed. In this review, we describe the main pharmacological ADHD treatments used and their main drawbacks. We present alternatives under study that would allow the customization of pharmacological treatments to overcome these drawbacks and achieve more reliable improvement of ADHD symptoms.

Pharmacotherapy of Traumatic Childhood Aphasia: Beneficial Effects of Donepezil Alone and Combined With Intensive Naming Therapy

At present, language therapy is the only available treatment for childhood aphasia (CA). Studying new interventions to augment and hasten the benefits provided by language therapy in children is strongly needed. CA frequently emerges as a consequence of traumatic brain injury and, as in the case of adults, it may be associated with dysfunctional activity of neurotransmitter systems. The use of cognitive-enhancing drugs, alone or combined with aphasia therapy, promotes improvement of language deficits in aphasic adults. In this study we report the case of a 9-year-old right-handed girl, subject P, who had chronic anomic aphasia associated with traumatic lesions in the left temporal-parietal cortex. We performed a single-subject, open-label study encompassing administration of the cholinergic agent donepezil (DP) alone during 12 weeks, followed by a combination of DP and intensive naming therapy (INT) for 2 weeks and thereafter by a continued treatment of DP alone during 12 weeks, a 4-week washout period, and another 2 weeks of INT. Four comprehensive language and neuropsychological evaluations were performed at different timepoints along the study, and multiple naming evaluations were performed after each INT in order to assess performance in treated and untreated words. Structural magnetic resonance imaging (MRI) was performed at baseline. MRI revealed two focal lesions in the left hemisphere, one large involving the posterior inferior and middle temporal gyri and another comprising the angular gyrus. Overall, baseline evaluation disclosed marked impairment in naming with mild-to-moderate compromise of spontaneous speech, repetition, and auditory comprehension. Executive and attention functions were also affected, but memory, visuoconstructive, and visuoperceptive functions were preserved. Treatment with DP alone significantly improved spontaneous speech, auditory comprehension, repetition, and picture naming, in addition to processing speed, selective, and sustained attention. Combined DP-INT further improved naming. After washout of both interventions, most of these beneficial changes remained. Importantly, DP produced no side effects and subject P attained the necessary level of language competence to return to regular schooling. In conclusion, the use of DP alone and in combination with INT improved language function and related cognitive posttraumatic deficits in a child with acquired aphasia. Further studies in larger samples are warranted.

Vortioxetine for attention deficit hyperactivity disorder in adults: A randomized, double-blind, placebo-controlled, proof-of-concept study

BACKGROUND

Stimulants remain the mainstay of treatment for attention-deficit hyperactivity disorder (ADHD) but are often associated with insufficient response or poor tolerability, leading to many patients not wishing to be treated with controlled substances.

AIMS

This randomized, placebo-controlled, proof-of-concept study (NCT02327013) evaluated the efficacy of a multimodal antidepressant, vortioxetine, in the treatment of ADHD, using a two-stage sequential parallel comparison design.

METHODS

Patients aged 18-55 years with a diagnosis of ADHD (DSM-5) and a total score ⩾24 on the Adult ADHD Investigator Symptom Rating Scale (AISRS) were randomized in study stage I with a 1:1:3 ratio to six weeks of treatment with vortioxetine 10 or 20 mg/day, or placebo ( n = 227). In study stage II, placebo non-responders (AISRS total score reduction <30% from stage I baseline) were re-randomized with a 1:1:1 ratio to six weeks of vortioxetine 10 or 20 mg/day, or placebo ( n = 59).

RESULTS

Across the two study stages combined, ADHD symptoms improved by approximately eight AISRS points in all treatment groups, showing no difference from placebo for either dose of vortioxetine, the study thus failing to meet its primary endpoint. However, both doses of vortioxetine separated from placebo in improving overall patient functioning, as measured by the Sheehan Disability Scale.

CONCLUSION

Studies are warranted to further investigate this suggested benefit of a multimodal antidepressant for patient functioning in ADHD while addressing issues of non-adherence and placebo response. The study confirmed vortioxetine 10 mg and 20 mg as generally well-tolerated.

Current issues in child and adolescent psychopharmacology. Part 1: Attention-deficit hyperactivity and affective disorders

Drug treatments play an important role in the treatment of child and adolescent psychiatric disorders. However, there is often a long delay before research findings are translated into clinical practice; furthermore, changes in clinical practice outstrip the available evidence. This paper focuses on current issues and research findings on the pharmacological treatment of attention-deficit hyperactivity disorder (ADHD) and affective disorders. Clinical findings from a US study of the treatment of ADHD with extended-release stimulants and non-stimulants, and the development and use of clinical guidelines are discussed. Clinical trials of selective serotonin reuptake inhibitors for early-onset depression, approaches to managing treatment-resistant depression and guidance on the drug treatment of early-onset mania are considered.

Treatment of adult ADHD: a clinical perspective

Adult attention deficit/hyperactivity disorder (ADHD) has moved from the blurred edge of clinical focus to clear recognition as a prevalent and significant disorder in its own right. It is a relatively common comorbidity which if identified and treated may open the door to better outcomes for hard-to-treat patients. Conversely, failure to identify and treat adult ADHD is linked to negative outcomes. The recognition of the importance of adult ADHD in a subset of our patients challenges us to overcome our anxiety about this diagnosis and prevent the societal marginalization of vulnerable patients. Adult ADHD responds well to integrated pharmacological and psychotherapeutic intervention. Its treatment responsiveness reduces disability and allows the comorbidity which is typically present to be addressed. Mastering this challenge can make the diagnosis and treatment of adult ADHD a rewarding experience.

Attention-deficit/hyperactivity disorder: neurophysiology, information processing, arousal and drug development

In this review, we draw on literature from both animal and human neurophysiological studies to consider the neurochemical mechanisms underlying attention-deficit/ hyperactivity disorder (ADHD). Psychophysiological and neuropsychological research is used to propose possible etiological endophenotypes of ADHD. These are conceptualized as patients with distinct cortical-arousal, information-processing or maturational abnormalities, or a combination thereof, and how the endophenotypes can be used to help drug development and optimize treatment and management. To illustrate, the paper focuses on neuro- and psychophysiological evidence that suggests cholinergic mechanisms may underlie specific information-processing abnormalities that occur in ADHD. The clinical implications for a cholinergic hypothesis of ADHD are considered, along with its possible implications for treatment and pharmacological development.

Efficacy and tolerability of pharmacotherapies for attention-deficit hyperactivity disorder in adults

This review examines the evidence regarding the efficacy and tolerability of long- and short-acting stimulant medications, as well as the non-stimulant medications atomoxetine and bupropion in the treatment of adult attention-deficit hyperactivity disorder (ADHD). Effect sizes in adults appear to be of almost the same magnitude as in school-age children when robust doses are used. There are adequate data demonstrating short-term efficacy and safety of medication in ADHD during adulthood but long-term studies are lacking, particularly in view of concerns regarding cardiovascular adverse events. There is some evidence that stimulant medication can improve driving performance in adults with ADHD. The extent to which medication may improve academic, occupational and social functioning in adults with ADHD is unclear, and future research should investigate these outcomes. Medication treatment of adults with ADHD in sports is controversial. Both stimulant and non-stimulant medications seem to be well tolerated. Monitoring of pulse and blood pressure is recommended with these drugs because of their cardiovascular effects. There have been extremely rare case reports of sudden death in adults and children treated with stimulants and atomoxetine, but it is difficult to clearly establish causality. In view of reports of treatment-related suicide-related behaviour with atomoxetine, it is recommended that adults should be observed for agitation, irritability, suicidal thinking, self-harming or unusual behaviour, particularly in the first months of treatment, or after a change of dose. ADHD in adults continues to remain an under-recognized disorder in many parts of the world and there is a lack of specialist clinics for assessment and treatment of adult ADHD. Studies to date have failed to show efficacy of medications in the treatment of ADHD in the substance misuse population. There is little evidence so far to suggest an increased misuse of stimulants or diversion amongst substance misusers; however, data are insufficient to draw firm conclusions. Further work is necessary to evaluate effective treatments in subgroups such as the substance misuse population, those with multiple co-morbidities and different ADHD subtypes.

Novel duplication on chromosome 16 (q12.1-q21) associated with behavioral disorder, mild cognitive impairment, speech delay, and dysmorphic features: case report

We report on the 10-year follow-up and clinical, cytogenetic, and molecular investigation of a girl admitted for evaluation because of speech delay, learning difficulties, aggressive behavior, and dysmorphic facial features that included high forehead, round face, epicanthic folds, low-set dysplastic ears, flat nasal bridge, long flat philtrum, thin upper lip, small mouth, and short neck. The analysis of high-resolution GTG- and CTG-banding chromosomes suggested a de novo direct duplication of 16q12-q21 region and fluorescence in situ hybridization analysis with whole-chromosome specific 16 probe confirmed that the duplicated genetic material originated from the chromosome 16. Subsequently, array-based comparative genomic hybridization analysis with a ≈ 75 kb resolution showed a 9.92 Mb gain on the long arm of chromosome 16 at bands q12.1 through q21. To the best of our knowledge, this is the first case of duplication 16q12.1q21 described in literature. Several genes within the duplicated region are possibly correlated with clinical features present in our patient. Clinical and cytogenetic findings were compared with the small number of reported patients with pure duplications 16q, partially overlapping the one in our patient. Clinical phenotype seems to be distinctive between the proximal-intermediate and intermediate-distal regions of the long arm of the chromosome 16. In particular, we observed a set of dysmorphic features that could present a characteristic dup 16q11.2-q13 phenotype. The present study illustrates the advantages of an integrative approach using both conventional and molecular techniques for the precise characterization and genotype-phenotype correlation in patients with dysmorphism, behavioral problems, and learning difficulties.

Chiropractic care for paediatric and adolescent Attention-Deficit/Hyperactivity Disorder: A systematic review

BACKGROUND

Psychostimulants are first line of therapy for paediatric and adolescent AD/HD. The evidence suggests that up to 30% of those prescribed stimulant medications do not show clinically significant outcomes. In addition, many children and adolescents experience side-effects from these medications. As a result, parents are seeking alternate interventions for their children. Complementary and alternative medicine therapies for behavioural disorders such as AD/HD are increasing with as many as 68% of parents having sought help from alternative practitioners, including chiropractors.

OBJECTIVE

The review seeks to answer the question of whether chiropractic care can reduce symptoms of inattention, impulsivity and hyperactivity for paediatric and adolescent AD/HD.

METHODS

Electronic databases (Cochrane CENTRAL register of Controlled Trials, Cochrane Database of Systematic reviews, MEDLINE, PsycINFO, CINAHL, Scopus, ISI Web of Science, Index to Chiropractic Literature) were searched from inception until July 2009 for English language studies for chiropractic care and AD/HD. Inclusion and exclusion criteria were applied to select studies. All randomised controlled trials were evaluated using the Jadad score and a checklist developed from the CONSORT (Consolidated Standards of Reporting Trials) guidelines.

RESULTS

The search yielded 58 citations of which 22 were intervention studies. Of these, only three studies were identified for paediatric and adolescent AD/HD cohorts. The methodological quality was poor and none of the studies qualified using inclusion criteria.

CONCLUSIONS

To date there is insufficient evidence to evaluate the efficacy of chiropractic care for paediatric and adolescent AD/HD. The claim that chiropractic care improves paediatric and adolescent AD/HD, is only supported by low levels of scientific evidence. In the interest of paediatric and adolescent health, if chiropractic care for AD/HD is to continue, more rigorous scientific research needs to be undertaken to examine the efficacy and effectiveness of chiropractic treatment. Adequately-sized RCTs using clinically relevant outcomes and standardised measures to examine the effectiveness of chiropractic care verses no-treatment/placebo control or standard care (pharmacological and psychosocial care) are needed to determine whether chiropractic care is an effective alternative intervention for paediatric and adolescent AD/HD.

Molecular genetics of attention deficit hyperactivity disorder

Although twin studies demonstrate that ADHD is a highly heritable condition, molecular genetic studies suggest that the genetic architecture of ADHD is complex. The handful of genome-wide linkage and association scans that have been conducted thus far show divergent findings and are, therefore, not conclusive. Similarly, many of the candidate genes reviewed here (ie, DBH, MAOA, SLC6A2, TPH-2, SLC6A4, CHRNA4, GRIN2A) are theoretically compelling from neurobiological systems perspective but available data are sparse and inconsistent. However, candidate gene studies of ADHD have produced substantial evidence implicating several genes in the etiology of the disorder, with meta-analyses supportive of a role of the genes coding for DRD4, DRD5, SLC6A3, SNAP-25, and HTR1B in the etiology of ADHD.

Pharmacotherapy of adult attention deficit hyperactivity disorder (ADHD): a meta-analysis

Our objective was to conduct a meta-analysis of therapeutic efficacy of pharmacological treatment of adult ADHD based on data from controlled clinical trials. We used the search engines PubMed and Medline to identify relevant clinical trials. Short-term studies with double-blind parallel-group design were selected for the analysis. Altogether, we identified 11 trials that met the criteria, and investigated a total of 1991 subjects, 694 and 1297 of whom were treated with placebo or active medication, respectively. In order to pool efficacy data from studies with different characteristics, including different number of participants, different trial duration and measures of efficacy, the statistical effect sizes for each study had to be calculated. Our findings showed that the pooled effect size across all treatments was in the medium-to-high range (Cohen's d=0.65, p<0.0001 vs. placebo), and the effect size for stimulants (Cohen's d=0.67, p<0.0001 vs. placebo) was somewhat higher than for non-stimulant medications (Cohen's d=0.59, p<0.0001 vs. placebo). The current database of controlled trials for adult ADHD is relatively small, and does not include data for many of the potentially important agents. In addition, effect-size estimates for different classes of medications (i.e. stimulant and non-stimulant medications) were based on separate studies; head-to-head comparisons of various agents are severely lacking. Nonetheless, results of this meta-analysis across all ADHD medications in adult subjects demonstrated statistically significant and clinically robust improvement in symptom severity compared to placebo treatment.

A high-density single-nucleotide polymorphism screen of 23 candidate genes in attention deficit hyperactivity disorder: suggesting multiple susceptibility genes among Chinese Han population

Attention deficit hyperactivity disorder (ADHD) is a common childhood-onset behavioral disorder with a definite genetic component. The search for genes predisposing to ADHD has focused on genes involved in the regulation of monoamine systems. In this study, we emphasized genes that underlie various aspects of dopamine, norepinephrine and serotonin neurotransmissions and performed a comprehensive association analysis by screening with 245 single-nucleotide polymorphisms (SNPs) of 23 candidate genes in a sample of Chinese Han descent. A total of 182 DSM-IV ADHD children and 184 healthy controls were genotyped and analyzed with an average density of one SNP every 6.1 kb. Both single-SNP and multi-marker haplotype analyses were implemented to exploit association signal for ADHD and its diagnostic subtypes. Empirical P-values were derived on the basis of 5000 permutations to evaluate gene-wide statistical significance. MAOA yielded highly suggestive evidence of association (empirical P<0.01, OR=1.94) with ADHD. For inattentive ADHD, MAOA, DDC and SYP showed suggestive evidence of association (empirical P<0.05). ADRA2C achieved suggestive significance (empirical P<0.05) for ADHD combined type. Additionally, for six genes (SNAP25, NET1, DBH, CHRNA4, DRD3 and SYT1) we detected one or more SNPs with nominal P-values</=0.05. This study has identified several genes as promising susceptibility loci for ADHD. Replication efforts and further investigations remain necessary to provide definite proof of association.

A randomised controlled trial of the Neuro Emotional Technique (NET) for childhood Attention Deficit Hyperactivity Disorder (ADHD): a protocol

BACKGROUND

An abundance of literature is dedicated to research for the treatment of Attention Deficit Hyperactivity Disorder (ADHD). Most, is in the area of pharmacological therapies with less emphasis in psychotherapy and psychosocial interventions and even less in the area of complementary and alternative medicine (CAM).The use of CAM has increased over the years, especially for developmental and behavioral disorders, such as ADHD. 60-65% of parents with children with ADHD have used CAM. Medical evidence supports a multidisciplinary approach (i.e. pharmacological and psychosocial) for the best clinical outcomes. The Neuro Emotional Technique (NET), a branch of Chiropractic, was designed to address the biopsychosocial aspects of acute and chronic conditions including non-musculoskeletal conditions. Anecdotally, it has been suggested that ADHD may be managed effectively by NET.

DESIGN/METHODS

A placebo controlled, double blind randomised clinical trial was designed to assess the effectiveness of NET on a cohort of children with medically diagnosed ADHD. Children aged 5-12 years who met the inclusion criteria were randomised to one of three groups. The control group continued on their existing medical regimen and the intervention and placebo groups had the addition of the NET and sham NET protocols added to their regimen respectively. These two groups attended a clinical facility twice a week for the first month and then once a month for six months. The Conners' Parent and Teacher Rating Scales (CRS) were used at the start of the study to establish baseline data and then in one month and in seven months time, at the conclusion of the study. The primary outcome measures chosen were the Conners' ADHD Index and Conners' Global Index. The secondary outcome measures chosen were the DSM-IV: Inattentive, the DSM-IV:Hyperactive-Impulsive, and the DSM-IV:Total subscales from the Conners' Rating Scales, monitoring changes in inattention, hyperactivity and impulsivity. Calculations for the sample size were set with a significance level of 0.05 and the power of 80%, yielding a sample size of 93.

DISCUSSION

The present study should provide information as to whether the addition of NET to an existing medical regimen can improve outcomes for children with ADHD.

TRIAL REGISTRATION

Australian New Zealand Clinical Trial Registration Number: ANZCTRN 012606000332527.

Quantitative electroencephalography and attention-deficit/hyperactivity disorder: implications for clinical practice

Although behavioral symptoms of inattention, impulsivity, and hyperactivity serve as a foundation for the accurate diagnosis of attention-deficit/hyperactivity disorder (ADHD), the low interrater reliability and specificity of behavioral rating scales and the absence of comprehensive screening for medical conditions that mimic ADHD have created a barrier to the effective treatment of ADHD. Recently published studies using quantitative electroencephalographic techniques have identified abnormal patterns of cortical activation through power spectral analysis, in event-related cortical potentials, and in slow cortical potentials that may serve as a basis for overcoming these barriers. This paper reviews the initial evidence indicating that power spectral analysis and event-related cortical potentials may be useful in differentiating ADHD from other psychiatric disorders, helping in medication selection, evaluating medication response, and improving the rate of treatment initiation and maintenance. Studies examining electroencephalogram biofeedback (neurotherapy) are reviewed using published efficacy guidelines.

A randomized controlled trial of a novel mixed monoamine reuptake inhibitor in adults with ADHD

BACKGROUND

NS2359 is a potent reuptake blocker of noradrenalin, dopamine, and serotonin. The aim of the study was to investigate the efficacy, safety and cognitive function of NS2359 in adults with a DSM IV diagnosis of ADHD.

METHODS

The study was a multi-centre, double-blind, randomized placebo-controlled, parallel group design in outpatient adults (18-55 years) testing 0.5 mg NS2359 vs. placebo for 8 weeks. Multiple assessments including computerized neuropsychological evaluation were performed.

RESULTS

There was no significant difference between NS2359 (n = 63) versus placebo (n = 63) on the primary outcome measure reduction in investigator rated ADHD-RS total score (7.8 versus 6.4; p < 0.45). However, in subjects with the inattentive subtype, there were significantly more responders in the NS2359 group compared to placebo (41% versus 7%; p < 0.01). For all secondary variables (ADHD-RS patient rated; The Conners Adult ADHD Scale; The Brown Adult Scale, and CGI-improvement scale) there were no significant differences between the two groups; however, in the inattentive subgroup, the response to treatment was significantly larger than to placebo. NS2359 improved composite factor scores of attention, episodic- and working memory. No serious adverse events were reported with insomnia, headaches and loss of appetite most commonly reported as side effects.

CONCLUSION

No overall effect of NS2359 was found on overall symptoms of ADHD. There was also a modest signal of improvement in the inattentive adults with ADHD and cognition warranting further exploration using differing doses.

Genetics of attention deficit hyperactivity disorder

Results of behavioral genetic and molecular genetic studies have converged to suggest that both genetic and nongenetic factors contribute to the development of attention deficit hyperactivity disorder (ADHD). Family, twin, and adoption studies provide compelling evidence that genes play a strong role in mediating susceptibility to ADHD. In contrast to a handful of genome-wide scans conducted thus far, many candidate gene studies of ADHD have produced substantial evidence implicating several genes in the etiology of the disorder. Yet, even these associations are small and consistent with the idea that the genetic vulnerability to ADHD is mediated by many genes of small effects. These small effects emphasize the need for future candidate gene studies to implement strategies that will provide enough statistical power to detect such small effects.

Osmotic, controlled-release methylphenidate for the treatment of ADHD

Methylphenidate (MPH) is the most commonly used and best-studied stimulant medication for attention-deficit hyperactivity disorder. However, its short duration of action usually results in a requirement to administer multiple daily doses in order to achieve optimal clinical benefit. Although a wax-matrix-based SR formulation of MPH has been available since the 1990s, it was not well accepted into clinical practice. The variable absorption profile and lack of an immediate-release component results in a slower onset of action compared with immediate-release MPH. Hence, there was a need to develop alternative longer-lasting preparations of MPH that were as efficacious as IR MPH, but which also addressed the problems inherent in multiple daily dosing. An osmotic, controlled-release (OROS) formulation of MPH HCl has been developed over the past 10 years for once-daily administration. OROS MPH has been widely accepted by clinicians and is now the most widely prescribed MPH product in North America. Clinical trials have shown OROS MPH to have a continued action over a 12-h period, to be superior to placebo and to be as effective as immediate-release MPH dosed three times daily, in reducing symptoms of attention-deficit hyperactivity disorder, with similar incidence of side effects. There have been a smaller number of trials comparing OROS MPH with non-stimulant treatments, such as atomoxetine.

Atomoxetine for attention-deficit/hyperactivity disorder symptoms in children with pervasive developmental disorders: a pilot study

OBJECTIVE

This pilot study examined the effects of atomoxetine on attention-deficit/hyperactivity disorder (ADHD) symptoms and autistic features in children with pervasive developmental disorders (PDD).

METHOD

Twelve children (aged 6-14 years) with PDD accompanied by ADHD symptoms entered a 10-week open-label study with atomoxetine (1.19 +/- 0.41 mg/kg/day). Response was assessed by using parent and clinician rating scales with change in the ADHD-Rating Scale (ADHDRS) as primary outcome measure.

RESULTS

Atomoxetine reduced ADHD-symptoms as measured by the ADHDRS (44% decrease vs. baseline, p < 0.003), the Conners' Parent Rating Scale-R:S (CPRS-R) (25% in the subscale "Cognitive Problems," p < 0.028; 32% in "Hyperactivity," p < 0.030; and 23% in "ADHD index," p < 0.023). We found a reduction of 21% (p = 0.071) for changes in the subscale "Hyperactivity" of the Aberrant Behavior Checklist (ABC). No change was found in any of the other ABC subscales, nor in the subscale "Oppositional" of the CPRS-R. Five patients (42%) discontinued because of side effects. Gastrointestinal symptoms, irritability, sleep problems, and fatigue were the most frequent side effects.

CONCLUSIONS

These preliminary findings indicate that atomoxetine may be a promising new agent in the treatment of ADHD symptoms in children with PDD. However, children with PDD may have a higher vulnerability for some of the known side-effects of atomoxetine.

Very early treatment with fluoxetine and reboxetine causing long-lasting change of the serotonin but not the noradrenaline transporter in the frontal cortex of rats

Interactions of the serotonergic and noradrenergic system at different sites of the brain may be important for efficacy and side effects of antidepressant drugs. Further, serotonin and noradrenaline play a critical role in the development of neurons during brain maturation. To gain further insight how brain maturation and the two monoaminergic systems are influenced by drug treatment during early postnatal development, this animal study investigated possible effects on the noradrenaline and serotonin transporter density of the frontal cortex very early in postnatal life. Rats were treated from postnatal day 2 to 5 either with fluoxetine (5 mg/kg per day s.c.) or with reboxetine (10 mg/kg per day s.c.). At day 90 the serotonin and noradrenaline transporter density in the frontal cortex was measured by ligand binding assay. Fluoxetine treatment led to a significant long-lasting increase of serotonin (not noradrenaline) transporter density (Bmax = 1231 +/- 34) in the frontal cortex (compared with saline-treated controls (Bmax = 1112 +/- 58)). Reboxetine treatment (surprisingly) led to an even more enhanced serotonin transporter density (Bmax = 1322 +/- 46), while noradrenaline transporter density seemed to be unaffected. There were no significant differences for KD values. The results support the idea that serotonin seems to play an important role during early brain development. Moreover, drug-related modulation of the noradrenergic system during brain maturation seems to cross-influence the serotonergic system.

Biophysical modeling of tonic cortical electrical activity in attention deficit hyperactivity disorder

Psychophysiological theories characterize Attention Deficit Hyperactivity Disorder (ADHD) in terms of cortical hypoarousal and a lack of inhibition of irrelevant sensory input, drawing on evidence of abnormal electroencephalographic (EEG) delta-theta activity. To investigate the mechanisms underlying this disorder a biophysical model of the cortex was used to fit and replicate the EEGs from 54 ADHD adolescents and their control subjects. The EEG abnormalities in ADHD were accounted for by the model's neurophysiological parameters as follows: (i) dendritic response times were increased, (ii) intrathalamic activity involving the thalamic reticular nucleus (TRN) was increased, consistent with enhanced delta-theta activity, and (iii) intracortical activity was increased, consistent with slow wave (<1 Hz) abnormalities. The longer dendritic response time is consistent with the increase in the activity of inhibitory cells types, particularly in the TRN, and therefore reduced arousal. The increase in intracortical activity may also reflect an increase in background activity or cortical noise within neocortical circuits. In terms of neurochemistry, these findings may be accounted for by disturbances in the cholinergic and/or noradrenergic systems. To the knowledge of the authors, this is the first study to use a detailed biophysical model of the brain to elucidate the neurophysiological mechanisms underlying tonic abnormalities in ADHD.

Molecular genetics of attention-deficit/hyperactivity disorder

Results of behavioral genetic and molecular genetic studies have converged to suggest that both genetic and nongenetic factors contribute to the development of attention-deficit/hyperactivity disorder (ADHD). We review this literature, with a particular emphasis on molecular genetic studies. Family, twin, and adoption studies provide compelling evidence that genes play a strong role in mediating susceptibility to ADHD. This fact is most clearly seen in the 20 extant twin studies, which estimate the heritability of ADHD to be .76. Molecular genetic studies suggest that the genetic architecture of ADHD is complex. The few genome-wide scans conducted thus far are not conclusive. In contrast, the many candidate gene studies of ADHD have produced substantial evidence implicating several genes in the etiology of the disorder. For the eight genes for which the same variant has been studied in three or more case-control or family-based studies, seven show statistically significant evidence of association with ADHD on the basis of the pooled odds ratio across studies: DRD4, DRD5, DAT, DBH, 5-HTT, HTR1B, and SNAP-25.

Stimulant drug action in attention deficit hyperactivity disorder (ADHD): inference of neurophysiological mechanisms via quantitative modelling

OBJECTIVE

To infer the neural mechanisms underlying tonic transitions in the electroencephalogram (EEG) in 11 adolescents diagnosed with attention deficit hyperactivity disorder (ADHD) before and after treatment with stimulant medication.

METHODS

A biophysical model was used to analyse electroencephalographic (EEG) measures of tonic brain activity at multiple scalp sites before and after treatment with medication.

RESULTS

It was observed that stimulants had the affect of significantly reducing the parameter controlling activation in the intrathalamic pathway involving the thalamic reticular nucleus (TRN) and the parameter controlling excitatory cortical activity. The effect of stimulant medication was also found to be preferentially localized within subcortical nuclei projecting towards frontal and central scalp sites.

CONCLUSIONS

It is suggested that the action of stimulant medication occurs via suppression of the locus coeruleus, which in turn reduces stimulation of the TRN, and improves cortical arousal. The effects localized to frontal and central sites are consistent with the occurrence of frontal delta-theta EEG abnormalities in ADHD, and existing theories of hypoarousal.

SIGNIFICANCE

To our knowledge, this is the first study where a detailed biophysical model of the brain has been used to estimate changes in neurophysiological parameters underlying the effects of stimulant medication in ADHD.

Non-stimulant medications in the treatment of ADHD

BACKGROUND

Stimulants are the first-line medication in the psychopharmacological treatment of attention-deficit hyperactivity disorder (ADHD). However, 10 to 30% of all children and adults with ADHD either do not respond to or do not tolerate treatment with stimulants.

OBJECTIVE

To describe alternative treatment approaches with various non-stimulant agents, especially atomoxetine.

METHOD

General review of empirically based literature concerning efficacy and safety of the substances.

RESULTS

A large and still increasing body of data supports the usefulness of atomoxetine, a once daily dosing, and new selective noradrenalin reuptake inhibitor, with few side effects. Atomoxetine has been licensed in the US for use in ADHD across the lifespan, and is currently under consideration in Europe. Other non-stimulant substances, such as tricyclic antidepressants (TCAs) and alpha-2-adrenergic agonists, which are used to treat ADHD, are also reviewed. TCAs have been well studied and shown to be efficacious in the treatment of ADHD, but are limited by side effects. The number of studies documenting the efficacy of alpha-2-adrenergic agonists is still limited. Some experimental studies support a potential role of cholinergic drugs such as acetylcholinesterase inhibitors (tacrine, donepezil) as well as novel nicotinic analogues (ABT-418).

CONCLUSION

Non-stimulant agents have been shown to be effective in treatment of ADHD. Especially, atomoxetine seems promising and newline drugs are in development.

Atomoxetine, a Novel Treatment for Attention-Deficit–Hyperactivity Disorder

Atomoxetine is the first nonstimulant drug approved by the United States Food and Drug Administration (FDA) for the treatment of attention-deficit-hyperactivity disorder (ADHD), and the only agent approved by the FDA for the treatment of ADHD in adults. Atomoxetine is a norepinephrine transport inhibitor that acts almost exclusively on the noradrenergic pathway. Its mechanism of action in the control and maintenance of ADHD symptoms is thought to be through the highly specific presynaptic inhibition of norepinephrine. Clinical trials to evaluate the short-term effects of atomoxetine in children and adults have shown that atomoxetine is effective in maintaining control of ADHD. Likewise, long-term trials have determined that atomoxetine is effective in preventing relapse of ADHD symptoms without an increase in adverse effects. A comparative trial of atomoxetine with methylphenidate in school-aged children indicated similar safety and efficacy without the abuse liability associated with some psychostimulants. The most commonly reported adverse effects in children and adolescents are dyspepsia, nausea, vomiting, decreased appetite, and weight loss. The rates of adverse events in the trials were similar for both the once- and twice-daily dosing regimens. The discontinuation rate was 3.5% in patients treated with atomoxetine versus 1.4% for placebo and appeared to be dose dependent, wit a higher percentage of discontinuation at dosages greater than 1.5 mg/kg/day. In clinical trials involving adults, the emergence of clinically significant or intolerable adverse events was low. The most common adverse events in adults were dry mouth, insomnia, nausea, decreased appetite, constipation, urinary retention or difficulties with micturition, erectile disturbance, dysmenorrhea, dizziness, and decreased libido. Sexual dysfunction occurred in approximately 2% of patients treated with atomoxetine. Atomoxetine should be used with caution in patients who have hypertension or any significant cardiovascular disorder. Overall, atomoxetine therapy in patient with ADHD appears to be effective in controlling symptoms and maintaining remission, with the advantages being comparable efficacy with that of methylphenidate, a favorable safety profile, and non-controlled substance status. Additional long-term studies are needed to determine its continued efficacy for those who require lifelong treatment, and comparative trials against other stimulant and nonstimulant agents.

Donepezil for Alzheimer's disease: pharmacodynamic, pharmacokinetic, and clinical profiles

Donepezil was developed in order to overcome the disadvantages of physostigmine and tacrine. Its use is based on the cholinergic hypothesis. Donepezil is a piperidine-based, reversible acetylcholinesterase inhibitor, that is chemically unrelated to other cholinesterase inhibitors. It was developed for the symptomatic treatment of Alzheimer's disease (AD). Donepezil is highly selective for acetylcholinesterase with a significantly lower affinity for butyrylcholinesterase, which is present predominantly in the periphery. Phase I and II clinical trials demonstrated donepezil's favorable pharmacokinetic, pharmacodynamic and safety profile. There is no need to modify the dose of donepezil in the elderly or in patients with renal and hepatic failure. Pivotal phase-III trials in the US, European countries, and Japan showed that donepezil significantly improved cognition and global function in patients with mild to moderate AD. In long-term trials, donepezil maintained cognitive and global function for up to 1 year prior to the resumption of gradual deterioration. Donepezil is generally well tolerated; most of its adverse events are mild, transient and cholinergic in nature. Donepezil produces no clinically significant changes in laboratory parameters, including liver function. The drug is approved for the treatment of mild to moderate Alzheimer's disease, but donepezil therapy does not have to be discontinued if a patient continues to deteriorate. Possible new indications for donepezil in psychiatric and neurologic diseases, other than AD, include dementia with Lewy bodies, brain injury, attention deficit hyperactivity, multiple sclerosis, Down's syndrome, delirium, mood disorders, Huntington's disease and sleep disorders.