Attention-Deficit Hyperactivity Disorder

Methodological adjustments for experimental studies including neurodiverse participants: A checklist for before, during, and after laboratory visits

In this paper, we developed an experimental checklist for laboratory experiments including neurodiverse participants, particularly those with attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and dyslexia. The checklist suggests additions to the basic requirements for ethical laboratory-based studies with human participants. The suggestions emphasize physical comfort, the agency of participants concerning environmental adjustments, clarity of communication, and a focus on participants' overall well-being. Those methodological guidelines aim to help researchers in facilitating inclusive and accessible laboratory environments for neurodiverse participants in order to: •Enhance research validity by minimizing the influence of factors that affect responses in neuroscience experiments.•Facilitate research recruitment by encouraging continued participation in future studies and increasing word-of-mouth.•Improve research dissemination by fostering a more positive perception of the research process amongst neurodiverse individuals and encouraging community involvement.

The Mental Health of Athletes: Recreational to Elite

ABSTRACT

Athletes at all levels of competition are susceptible to mental health symptoms and disorders, and this has been a topic of increased research attention in recent years. The most common such conditions will be highlighted in this article, with a clinical focus on unique aspects of presentation, diagnosis, and management among athletes. Conditions addressed include depression, anxiety and related disorders, eating disorders, sleep concerns, attention-deficit/hyperactivity disorder, bipolar and psychotic disorders, and substance use disorders and behavioral addictions. Athletes experience particular physiologic and psychosocial demands that impact how they present symptomatically and how treatment modalities, including psychotherapy and pharmacologic treatments, impact them.

Efficacy and Safety of Dasotraline in Children With ADHD: A Laboratory Classroom Study

Objective: To evaluate the efficacy and safety of dasotraline for treatment of ADHD in children. Method: Children (ages 6-12 years; N = 112) with ADHD were randomized, double-blind, to 14 days of once-daily evening doses of dasotraline 4 mg or placebo. ADHD symptom severity was measured at baseline and Day 15 in seven, 30-min classroom sessions using the Swanson, Kotkin, Agler, M-Flynn, and Pelham (SKAMP) and the Permanent Product Measure of Performance (PERMP) math test. Results: Significant improvement was observed for dasotraline versus placebo in the SKAMP-combined score (-3.2 vs. +2.0; p < .001; effect size = 0.85) and SKAMP and PERMP subscale scores. The three most common adverse events for dasotraline (vs. placebo) were insomnia (19.6% vs. 3.6%), headache (10.7% vs. 8.9%), and decreased appetite (10.7% vs. 3.6%). Conclusion: In this laboratory classroom study, dasotraline 4 mg was found to be an efficacious and generally well-tolerated treatment for ADHD in children aged 6 to 12 years.

Altered kynurenine pathway metabolites in a mouse model of human attention-deficit hyperactivity/autism spectrum disorders: A potential new biological diagnostic marker

Deleterious mutations in patchd1 domain containing 1 (PTCHD1) gene have been identified in patients with intellectual disability and/or autism spectrum disorder (ASD). To clarify the causal relationship between Ptchd1 deficiency and behavioral defects relevant to neurodevelopmental disorders, we generated global Ptchd1 knockout (KO) mice. Ptchd1 KO mice displayed hyperlocomotion, increased impulsivity, and lower recognition memory, which resemble attention-deficit hyperactivity disorder (ADHD)-like behaviors. Acute or chronic treatment with atomoxetine ameliorated almost all behavioral deficits in Pthcd1 KO mice. We next determined possible involvement of the kynurenine pathway (KP) metabolites in neurodevelopmental disorders in Ptchd1 KO mice and assessed the potential of KP metabolites as biomarkers for ADHD and/or ASD. Ptchd1 KO mice showed drastic changes in KP metabolite concentrations in the serum and the brain, indicating that the activated KP is associated with ADHD-like behaviors. Our findings indicate that Ptchd1 KO mice can be used as an animal model of human ADHD and/or ASD, and KP metabolites are potential diagnostic biomarkers for neurodevelopmental disorders.

Attention-deficit/hyperactivity disorder in elite athletes: a narrative review

Attention-deficit/hyperactivity disorder (ADHD) is a common brain developmental disorder in the general population that may be even more prevalent in elite athletes in certain sports. General population studies of ADHD are extensive and have reported on prevalence, symptoms, therapeutic and adverse effects of treatment and new clinical and research findings. However, few studies have reported on prevalence, symptoms and treatments of ADHD in elite athletes. This narrative review summarises the literature on symptoms, comorbidities, effects of ADHD on performance and management options for elite athletes with ADHD. The prevalence of ADHD in student athletes and elite athletes may be 7%–8%. The symptoms and characteristics of ADHD play a role in athletes’ choice of a sport career and further achieving elite status. Proper management of ADHD in elite athletes is important for safety and performance, and options include pharmacologic and psychosocial treatments.

Dasotraline in Children with Attention-Deficit/Hyperactivity Disorder: A Six-Week, Placebo-Controlled, Fixed-Dose Trial

OBJECTIVE

Dasotraline is a potent inhibitor of presynaptic dopamine and norepinephrine reuptake with a pharmacokinetic profile characterized by slow absorption and a long elimination half-life. The aim of this study was to evaluate the efficacy and safety of dasotraline in children with attention-deficit/hyperactivity disorder (ADHD).

METHODS

Children aged 6-12 years with a Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnosis of ADHD were randomized to 6 weeks of double-blind once-daily treatment with dasotraline (2 or 4 mg) or placebo. The primary efficacy endpoint was change from baseline in the ADHD Rating Scale Version IV-Home Version (ADHD RS-IV HV) total score at week 6.

RESULTS

A total of 342 patients were randomized to dasotraline or placebo (mean age 9.1 years, 66.7% male). Treatment with dasotraline was associated with significant improvement at study endpoint in the ADHD RS-IV HV total score for the 4 mg/day dose versus placebo (-17.5 vs. -11.4; p < 0.001; effect size [ES], 0.48), but not for the 2 mg/day dose (-11.8 vs. -11.4; ns; ES, 0.03). A regression analysis confirmed a significant linear dose-response relationship for dasotraline. Significant improvement for dasotraline 4 mg/day dose versus placebo was also observed across the majority of secondary efficacy endpoints, including the Clinical Global Impression (CGI)-Severity score, the Conners Parent Rating Scale-Revised scale (CPRS-R) ADHD index score, and subscale measures of hyperactivity and inattentiveness. Discontinuation rates due to adverse events (AEs) were higher in the dasotraline 4 mg/day group (12.2%) compared with the 2 mg/day group (6.3%) and placebo (1.7%). The most frequent AEs associated with dasotraline were insomnia, decreased appetite, decreased weight, and irritability. Psychosis-related symptoms were reported as AEs by 7/219 patients treated with dasotraline in this study. There were no serious AEs or clinically meaningful changes in blood pressure or heart rate on dasotraline.

CONCLUSION

In this placebo-controlled study, treatment with dasotraline 4 mg/day significantly improved ADHD symptoms and behaviors, including attention and hyperactivity, in children aged 6-12 years. The most frequently reported AEs observed on dasotraline included insomnia, decreased appetite, decreased weight, and irritability.

Attention Deficit Hyperactivity Disorder: Unique Considerations in Athletes

Context:

Attention deficit hyperactivity disorder (ADHD) is a common psychiatric condition in the general population, with evidence suggesting that it may be more common among athletes.

Evidence Acquisition:

Literature searches were performed on PubMed, MEDLINE, and Cochrane databases for the years 2000 to 2016 utilizing the following key search terms: ADHD, ADD, guidelines, diagnosis, athlete, sports, treatment, pharmacotherapy, stimulants, risk, cardiovascular effects, concussion, and traumatic brain injury (TBI).

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Results:

ADHD exists among athletes at all levels of play, and symptomatology overlaps significantly with that of concussion. Treatment with stimulants has cardiovascular effects and may not be permitted by the athlete’s governing body. An athlete’s level of competition and individual cardiovascular risk factors may therefore affect medication choices.

Conclusion:

ADHD diagnosis and treatment are paramount to optimal quality of life and functioning in affected individuals. Pharmacologic treatment options should not specifically be avoided in athletes; however, stimulant use is an independent risk factor for heat illness. Concussion, a common athletic injury, may have an altered course in those affected by ADHD, specifically with regard to neurocognitive testing and recovery.

The Effect of Methylphenidate on the Hearing of Children with Attention Deficit Hyperactivity Disorder

Introduction  There has been a sudden idiopathic hearing loss case presented after methylphenidate treatment in a child with attention deficit hyperactivity disorder (ADHD).

Objective  This study was performed to reveal the probable ototoxic side effects of methylphenidate use in patients with ADHD.

Methods  Thirty pediatric patients with ADHD were included in the study. Pure tone audiometry, speech discrimination scores, waves I, III, V absolute latencies and waves I-III, I-V, III-V interpeak latencies at the 80 dB nHL intensity after click stimulus auditory brainstem response (ABR) results were compared before and 3 months after methylphenidate treatment.

Results  There were no statistically significant difference between pretreatment and posttreatment pure tone and speech audiometry findings and ABR results (p > 0.05 for all parameters).

Conclusion  Methylphenidate can be regarded as a safe drug regarding ototoxic side effects. Additional studies with a larger sample size and longer follow-up may be needed.

A Review of Pharmacological Management of Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a common psychological diagnosis in children. This disorder impacts children and adolescents in all areas of life, including academic performance, extracurricular activities, and social interactions. ADHD can continue into adulthood where unemployment and substance abuse has been described. Although behavioral therapy is recommended for all patients with ADHD, medication management typically is initiated soon after diagnosis. Psychostimulants remain the primary medication of choice. This review focuses on the clinical use of psychostimulant medication in children and adolescents. The pharmacodynamic and pharmacokinetic differences between the newest long-acting formulations as well as commonly encountered adverse drug reactions, with suggested management strategies, will be highlighted. Non-stimulant therapy with atomoxetine or alpha2-adrenergic agonists is also reviewed. These agents may be warranted for patients who cannot tolerate psychostimulant therapy or have a comorbid condition. Finally, the 8-year multimodal treatment study results are also discussed.

Latest trends in ADHD drug prescribing patterns in children in the UK: prevalence, incidence and persistence

OBJECTIVES

To investigate attention deficit and hyperactivity disorder (ADHD) drug prescribing in children under 16 years old in the UK between 1992 and 2013.

METHODS

All patients under 16 registered in the Clinical Practice Research Datalink (CPRD) with a minimum of 1 year of observation time and who received at least one prescription of any ADHD drug between 1 January 1992 and 31 December 2013.Trends in prevalence and incidence of use of ADHD drugs in children were calculated between 1995 and 2013 and persistence in new users was estimated.

RESULTS

The prevalence of ADHD drug use in children under 16 increased 34-fold overall, rising from 1.5 95% CI (1.1 to 2.0) per 10 000 children in 1995 to 50.7 95% CI (49.2 to 52.1) per 10 000 children in 2008 then stabilising to 51.1 95% CI (49.7 to 52.6) per 10 000 children in 2013. The rate of new users increased eightfold reaching 10.2 95% CI (9.5 to 10.9) per 10 000 children in 2007 then decreasing to 9.1 95% CI (8.5 to 9.7) per 10 000 children in 2013. Although prevalence and incidence increased rather steeply after 1995, this trend seems to halt from 2008 onwards. We identified that 77%, 95% CI (76% to 78%) of children were still under treatment after 1 year and 60% 95% CI (59% to 61%) after 2 years.

CONCLUSIONS

There was a marked increase in ADHD drug use among children in the UK from 1992 until around 2008, with stable levels of use since then. UK children show relatively long persistence of treatment with ADHD medications compared to other countries.

Noninvasive Brain Stimulation in Pediatric Attention-Deficit Hyperactivity Disorder (ADHD): A Review

Attention-deficit hyperactivity disorder (ADHD) is one of the most prevalent neurodevelopmental disorders in the pediatric population. The clinical management of ADHD is currently limited by a lack of reliable diagnostic biomarkers and inadequate therapy for a minority of patients who do not respond to standard pharmacotherapy. There is optimism that noninvasive brain stimulation may help to address these limitations. Transcranial magnetic stimulation and transcranial direct current stimulation are 2 methods of noninvasive brain stimulation that modulate cortical excitability and brain network activity. Transcranial magnetic stimulation can be used diagnostically to probe cortical neurophysiology, whereas daily use of repetitive transcranial magnetic stimulation or transcranial direct current stimulation can induce long-lasting and potentially therapeutic changes in targeted networks. In this review, we highlight research showing the potential diagnostic and therapeutic applications of transcranial magnetic stimulation and transcranial direct current stimulation in pediatric ADHD. We also discuss the safety and ethics of using these tools in the pediatric population.

Individualization of treatments with drugs metabolized by CES1: combining genetics and metabolomics

CES1 is involved in the hydrolysis of ester group-containing xenobiotic and endobiotic compounds including several essential and commonly used drugs. The individual variation in the efficacy and tolerability of many drugs metabolized by CES1 is considerable. Hence, there is a large interest in individualizing the treatment with these drugs. The present review addresses the issue of individualized treatment with drugs metabolized by CES1. It describes the composition of the gene encoding CES1, reports variants of this gene with focus upon those with a potential effect on drug metabolism and provides an overview of the protein structure of this enzyme bringing notice to mechanisms involved in the regulation of enzyme activity. Subsequently, the review highlights drugs metabolized by CES1 and argues that individual differences in the pharmacokinetics of these drugs play an important role in determining drug response and tolerability suggesting prospects for individualized drug therapies. Our review also discusses endogenous substrates of CES1 and assesses the potential of using metabolomic profiling of blood to identify proxies for the hepatic activity of CES1 that predict the rate of drug metabolism. Finally, the combination of genetics and metabolomics to obtain an accurate prediction of the individual response to CES1-dependent drugs is discussed.

Premarket safety and efficacy studies for ADHD medications in children

BACKGROUND

Attention-deficit hyperactivity disorder (ADHD) is a chronic condition and pharmacotherapy is the mainstay of treatment, with a variety of ADHD medications available to patients. However, it is unclear to what extent the long-term safety and efficacy of ADHD drugs have been evaluated prior to their market authorization. We aimed to quantify the number of participants studied and their length of exposure in ADHD drug trials prior to marketing.

METHODS

We identified all ADHD medications approved by the Food and Drug Administration (FDA) and extracted data on clinical trials performed by the sponsor and used by the FDA to evaluate the drug's clinical efficacy and safety. For each ADHD medication, we measured the total number of participants studied and the length of participant exposure and identified any FDA requests for post-marketing trials.

RESULTS

A total of 32 clinical trials were conducted for the approval of 20 ADHD drugs. The median number of participants studied per drug was 75 (IQR 0, 419). Eleven drugs (55%) were approved after <100 participants were studied and 14 (70%) after <300 participants. The median trial length prior to approval was 4 weeks (IQR 2, 9), with 5 (38%) drugs approved after participants were studied <4 weeks and 10 (77%) after <6 months. Six drugs were approved with requests for specific additional post-marketing trials, of which 2 were performed.

CONCLUSIONS

Clinical trials conducted for the approval of many ADHD drugs have not been designed to assess rare adverse events or long-term safety and efficacy. While post-marketing studies can fill in some of the gaps, better assurance is needed that the proper trials are conducted either before or after a new medication is approved.

Period prevalence of concomitant psychotropic medication usage among children and adolescents with attention-deficit/hyperactivity disorder during 2009

OBJECTIVE

Stimulants are recommended as a first-line treatment for attention- deficit/hyperactivity disorder (ADHD); however, a subset of the patient population augments their stimulant treatment with other medications. The objective of this study was to estimate the 1 year period prevalence of concomitant psychotropic medication use among children and adolescents with ADHD during 2009.

METHODS

Patients 6-17 years of age with one or more primary ADHD diagnoses between July 1, 2008 and December 31, 2009 and one or more stimulant prescription fills during 2009 were identified from a large United States commercial claims database. Concomitant psychotropic medication use, defined as 30 days of continuous medication supply overlap between the augmenting agent and stimulant, was evaluated for 14 distinct psychotropic medication categories (6 with a United States Food and Drug Administration (FDA) approved indication for ADHD, 8 without an indication for ADHD). The 1 year period prevalence of concomitant psychotropic medication use (both overall and within each medication category) was calculated and compared between patients with and without psychiatric or neurologic comorbidities. Children (6-12 years) and adolescents (13-17 years) were evaluated separately.

RESULTS

A total of 71,201 children and 49,959 adolescents met the inclusion criteria. The 1 year period prevalence of concomitant psychotropic medication use among children and adolescents was 20.3% and 23.4%, with 5.7% and 6.7% augmenting with two or more medication categories, respectively. The most common concomitant medication categories were selective serotonin reuptake inhibitors (SSRIs) (children: 6.2%; adolescents: 11.4%), atypical antipsychotics (5.8%; 6.8%) and clonidine immediate release (5.4%; 2.9%). Children and adolescents with psychiatric or neurologic comorbidities had higher rates of augmentation than did those without comorbidities (all p<0.001).

CONCLUSIONS

This epidemiologic study found that the prevalence of concomitant psychotropic medication use in children and adolescents ranged from 12.6% for noncomorbid ADHD to 41.7% for comorbid ADHD, in 2009. Future research is warranted to evaluate the rationale for, and clinical benefit of, concomitant psychotropic medication usage in patients with ADHD.

Effective use of transdermal drug delivery in children

Transdermal administration offers a non-invasive and convenient method for paediatric drug delivery. The competent skin barrier function in term infants and older children limits both water loss and the percutaneous entry of chemicals including drugs; but the smaller doses required by children eases the attainment of therapeutic concentrations. Transdermal patches used in paediatrics include fentanyl, buprenorphine, clonidine, scopolamine, methylphenidate, oestrogens, nicotine and tulobuterol. Some patches have paediatric labelling supported by clinical trials whereas others are used unlicensed. Innovative drug delivery methods, such as microneedles and sonophoresis are being tested for their safety and efficacy; needleless injectors are primarily used to administer growth hormone; and two iontophoretic devices were approved for paediatrics. In contrast, the immature and rapidly evolving skin barrier function in premature neonates represents a significant formulation challenge. Unfortunately, this population group suffers from an absence of approved transdermal formulations, a shortcoming exacerbated by the significant risk of excessive drug exposure via the incompletely formed skin barrier.

Systematic review of atomoxetine data in childhood and adolescent attention-deficit hyperactivity disorder 2009-2011: focus on clinical efficacy and safety

BACKGROUND

Clinicians obtain critical prescribing knowledge from clinical papers and review articles. This is the first published systematic review of clinical atomoxetine data covering 2009-2011.

OBJECTIVE

We aim to update clinicians on current clinical atomoxetine data with specific reference to time of onset of efficacy and maximal efficacy. These data may allow critical analysis of comparative efficacy between atomoxetine and stimulant medications.

METHODS

A formal systematic review of atomoxetine data from January 2009-June 2011 was conducted. The search term used was "atomoxetine" in the English language. The search yielded 747 citations from which 106 are clinical data. This paper includes clinical efficacy and safety data and excludes quality-of-life and review papers.

RESULTS

Atomoxetine has an onset of action within 4 weeks (possibly within 1 week in subsequent responders) but requires at least 12 weeks for full response to be demonstrated. Treatment-naïve cohorts (6-12 weeks) report effect sizes of 0.6-1.3. Using minimum 6-week clinical trial criteria, atomoxetine may demonstrate similar efficacy to methylphenidate comparing reduction in core ADHD symptoms in meta-analysis, although the diversity of the data makes interpretation complex. From epidemiological databases, cardiovascular and suicide-related events were similar to those seen in patients taking methylphenidate.

CONCLUSIONS

Incremental response time to atomoxetine should be considered in the design of future comparative efficacy trials.

Efficacy of lisdexamfetamine dimesylate throughout the day in children and adolescents with attention-deficit/hyperactivity disorder: results from a randomized, controlled trial

Lisdexamfetamine dimesylate (LDX) is a long-acting, prodrug stimulant therapy for patients with attention-deficit/hyperactivity disorder (ADHD). This randomized placebo-controlled trial of an optimized daily dose of LDX (30, 50 or 70 mg) was conducted in children and adolescents (aged 6-17 years) with ADHD. To evaluate the efficacy of LDX throughout the day, symptoms and behaviors of ADHD were evaluated using an abbreviated version of the Conners' Parent Rating Scale-Revised (CPRS-R) at 1000, 1400 and 1800 hours following early morning dosing (0700 hours). Osmotic-release oral system methylphenidate (OROS-MPH) was included as a reference treatment, but the study was not designed to support a statistical comparison between LDX and OROS-MPH. The full analysis set comprised 317 patients (LDX, n = 104; placebo, n = 106; OROS-MPH, n = 107). At baseline, CPRS-R total scores were similar across treatment groups. At endpoint, differences (active treatment - placebo) in least squares (LS) mean change from baseline CPRS-R total scores were statistically significant (P < 0.001) throughout the day for LDX (effect sizes: 1000 hours, 1.42; 1400 hours, 1.41; 1800 hours, 1.30) and OROS-MPH (effect sizes: 1000 hours, 1.04; 1400 hours, 0.98; 1800 hours, 0.92). Differences in LS mean change from baseline to endpoint were statistically significant (P < 0.001) for both active treatments in all four subscales of the CPRS-R (ADHD index, oppositional, hyperactivity and cognitive). In conclusion, improvements relative to placebo in ADHD-related symptoms and behaviors in children and adolescents receiving a single morning dose of LDX or OROS-MPH were maintained throughout the day and were ongoing at the last measurement in the evening (1800 hours).

Extending therapeutic use of psychostimulants: focus on serotonin-1A receptor

INTRODUCTION

Despite a number of medicinally important pharmacological effects, the therapeutic use of psychostimulants is limited because of abuse potential and psychosis following long term use. Development of pharmacological agents for improving and extending therapeutic use of psychostimulants in narcolepsy, attention deficit hyperactivity disorder, Parkinson's disease, obesity and as cognitive enhancer is an important research imperative. In this regard, one potential target system is the 5-hydroxytryptamine (5-HT; serotonin) neurotransmitter system. The focus of the present article is to evaluate a potential role of 5-HT-1A receptor in the alleviation of abuse potential and psychosis-induced by prescription psychostimulants amphetamines and apomorphine.

METHOD

Synaptic contacts between dopamine systems and 5-HT-1A receptors are traced. Studies on serotonin-1A influences on the modulation of dopamine neurotransmission and psychostimulant-induced behavioral sensitization are accumulated.

RESULTS

Inhibition of amphetamine and apomorphine-induced behavioral sensitization by co administration of 5-HT-1A agonists cannot be explained in terms of direct activation of 5-HT-1A receptors, because activation of pre- as well as postsynaptic 5-HT-1A receptors tends to increase dopamine neurotransmission.

CONCLUSION

Long term use of amphetamine and apomorphine produces adaptive changes in 5-HT-1A receptor mediated functions, which are prevented by the co-use of 5-HT-1A agonists. In view of extending medicinal use of psychostimulants, it is important to evaluate the effects of co-use of 5-HT-1A agonists on potential therapeutic profile of amphetamine and apomorphine in preclinical research. It is also important to evaluate the functional significance of 5-HT-1A receptors on psychostimulant-induced behaviors in other addiction models such as drug self-administration and reinstatement of drug seeking behavior.

European, randomized, phase 3 study of lisdexamfetamine dimesylate in children and adolescents with attention-deficit/hyperactivity disorder

This study evaluated the efficacy and safety of lisdexamfetamine dimesylate (LDX) compared with placebo in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) in Europe. Osmotic-release oral system methylphenidate (OROS-MPH) was included as a reference arm. Patients (6-17 years old) with a baseline ADHD Rating Scale version IV (ADHD-RS-IV) total score ≥ 28 were randomized (1:1:1) to dose-optimized LDX (30, 50, or 70 mg/day), OROS-MPH (18, 36, or 54 mg/day) or placebo for 7 weeks. Primary and key secondary efficacy measures were the investigator-rated ADHD-RS-IV and the Clinical Global Impressions-Improvement (CGI-I) rating, respectively. Safety assessments included treatment-emergent adverse events (TEAEs), electrocardiograms, and vital signs. Of 336 patients randomized, 196 completed the study. The difference between LDX and placebo in least squares mean change in ADHD-RS-IV total score from baseline to endpoint was -18.6 (95% confidence interval [CI]: -21.5 to -15.7) (p<0.001; effect size, 1.80). The difference between OROS-MPH and placebo in least squares mean change in ADHD-RS-IV total score from baseline to endpoint was -13.0 (95% CI: -15.9 to -10.2) (p<0.001; effect size, 1.26). The proportions (95% CI) of patients showing improvement (CGI-I of 1 or 2) at endpoint were 78% (70-86), 14% (8-21), and 61% (51-70) for LDX, placebo, and OROS-MPH. The most common TEAEs for LDX were decreased appetite, headache, and insomnia. Mean changes in vital signs were modest and consistent with the known profile of LDX. LDX was effective and generally well tolerated in children and adolescents with ADHD.

Importance of pharmacogenetics in the treatment of children with attention deficit hyperactive disorder: a case report

This case report highlights the importance of pharmacogenetic testing in the treatment of attention deficit hyperactive disorder (ADHD). A 6-year-old boy diagnosed with ADHD was prescribed methylphenidate 5 mg twice daily (7 am and noon) and the family was compliant with administration of this medication. On the first day of treatment, the patient had an adverse reaction, becoming disobedient, more mischievous, erratic, resistant to discipline, would not go to sleep until midnight, and had a poor appetite. The All-In-One PGX (All-In-One Pharmacogenetics for Antipsychotics test for CYP2D6, CYP2C19, and CYP2C9) was performed using microarray-based and real-time polymerase chain reaction techniques. The genotype of our patient was identified to be CYP2D6*2/*10, with isoforms of the enzyme consistent with a predicted cytochrome P450 2D6 intermediate metabolizer phenotype. Consequently, the physician adjusted the methylphenidate dose to 2.5 mg once daily in the morning. At this dosage, the patient had a good response without any further adverse reactions. Pharmacogenetic testing should be included in the management plan for ADHD. In this case, cooperation between the medical team and the patients’ relatives was key to successful treatment.

A post hoc comparison of the effects of lisdexamfetamine dimesylate and osmotic-release oral system methylphenidate on symptoms of attention-deficit hyperactivity disorder in children and adolescents

INTRODUCTION

There are limited head-to-head data comparing the efficacy of long-acting amfetamine- and methylphenidate-based psychostimulants as treatments for individuals with attention-deficit hyperactivity disorder (ADHD). This post hoc analysis provides the first parallel-group comparison of the effect of lisdexamfetamine dimesylate (lisdexamfetamine) and osmotic-release oral system methylphenidate (OROS-MPH) on symptoms of ADHD in children and adolescents.

STUDY DESIGN

This was a post hoc analysis of a randomized, double-blind, parallel-group, dose-optimized, placebo-controlled, phase III study.

SETTING

The phase III study was carried out in 48 centres across ten European countries.

PATIENTS

The phase III study enrolled children and adolescents (aged 6-17 years) who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria for a primary diagnosis of ADHD and who had a baseline ADHD Rating Scale IV (ADHD-RS-IV) total score of 28 or higher.

INTERVENTION

Eligible patients were randomized (1:1:1) to receive a once-daily, optimized dose of lisdexamfetamine (30, 50 or 70 mg/day), placebo or OROS-MPH (18, 36 or 54 mg/day) for 7 weeks.

MAIN OUTCOME MEASURES

In this post hoc analysis, efficacy was assessed using the ADHD-RS-IV and Clinical Global Impressions-Improvement (CGI-I) scale. Responders were defined as those achieving at least a 30% reduction from baseline in ADHD-RS-IV total score and a CGI-I score of 1 (very much improved) or 2 (much improved). The proportion of patients achieving an ADHD-RS-IV total score less than or equal to the mean for their age (based on normative data) was also determined. Endpoint was the last on-treatment visit with a valid assessment. Safety assessments included treatment-emergent adverse events (TEAEs) and vital signs.

RESULTS

Of the 336 patients randomized, 332 were included in the safety population, 317 were included in the full analysis set and 196 completed the study. The mean (standard deviation) ADHD-RS-IV total score at baseline was 40.7 (7.31) for lisdexamfetamine, 41.0 (7.14) for placebo and 40.5 (6.72) for OROS-MPH. The least-squares (LS) mean change (standard error) in ADHD-RS-IV total score from baseline to endpoint was -24.3 (1.16) for lisdexamfetamine, -5.7 (1.13) for placebo and -18.7 (1.14) for OROS-MPH. The difference between lisdexamfetamine and OROS-MPH in LS mean change (95% confidence interval [CI]) in ADHD-RS-IV total score from baseline to endpoint was statistically significant in favour of lisdexamfetamine (-5.6 [-8.4 to -2.7]; p < 0.001). The difference between lisdexamfetamine and OROS-MPH in the percentage of patients (95% CI) with a CGI-I score of 1 or 2 at endpoint was 17.4 (5.0-29.8; p < 0.05; number needed to treat [NNT] 6), and the difference in the percentage of patients (95% CI) achieving at least a 30% reduction in ADHD-RS-IV total score and a CGI-I score of 1 or 2 was 18.3 (5.4-31.3; p < 0.05; NNT 6). The difference between lisdexamfetamine and OROS-MPH in the percentage of patients (95% CI) with an ADHD-RS-IV total score less than or equal to the mean for their age at endpoint was 14.0 (0.6-27.4; p = 0.050). The overall frequency of TEAEs and the frequencies of decreased appetite, insomnia, decreased weight, nausea and anorexia TEAEs were greater in patients treated with lisdexamfetamine than in those treated with OROS-MPH, whereas headache and nasopharyngitis were more frequently reported in patients receiving OROS-MPH.

CONCLUSIONS

This post hoc analysis showed that, at the doses tested, patients treated with lisdexamfetamine showed statistically significantly greater improvement in symptoms of ADHD than those receiving OROS-MPH, as assessed using the ADHD-RS-IV and CGI-I. The safety profiles of lisdexamfetamine and OROS-MPH were consistent with the known effects of stimulant medications.

Drug therapy of attention deficit hyperactivity disorder: current trends

Attention deficit hyperactivity disorder is a developmental disorder with an age onset prior to 7 years. Children with ADHD have significantly lower ability to focus and sustain attention and also score higher on impulsivity and hyperactivity. Stimulants, such as methylphenidate, have remained the mainstay of ADHD treatment for decades with evidence supporting their use. However, recent years have seen emergence of newer drugs and drug delivery systems, like osmotic release oral systems and transdermal patches, to mention a few. The use of nonstimulant drugs like atomoxetine and various other drugs, such as α-agonists, and a few antidepressants, being used in an off-label manner, have added to the pharmacotherapy of ADHD. This review discusses current trends in drug therapy of ADHD and highlights the promise pharmacogenomics may hold in the future.

Guanfacine ER for the treatment of adolescent attention-deficit/hyperactivity disorder

INTRODUCTION

Guanfacine extended release (GXR) is an alpha 1A noradrenergic agonist that has been approved by the FDA for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) as a monotherapy, and as an adjunctive therapy to stimulants for the treatment of ADHD in children and adolescents age 6 - 17.

AREAS COVERED

PubMed, the Ovid Medline database, and the PsycInfo database were searched using the term 'guanfacine'. Results were then limited to criteria such as English and human, from 1990 through December 2011. The resulting yield from the comprehensive literature search was 4391 articles. The titles and abstracts of all articles were reviewed. Studies were selected for full-text review based upon their place in the hierarchy of evidence (e.g., randomized controlled trials), relevance and quality of individual studies, and generalizability to clinical practice. The search was augmented by further search of article reference lists. A total of 15 articles were selected for full-text examination.

EXPERT OPINION

Due to the absence of positive evidence for the efficacy of GXR for monotherapy in adolescents, clinicians should be guarded in the use of GXR for monotherapy in adolescents with ADHD. The use of GXR has considerable promise as an adjunct to stimulants for other behavioral conditions associated with ADHD.

Lisdexamfetamine dimesylate: a new therapeutic option for attention-deficit hyperactivity disorder

Attention-deficit hyperactivity disorder (ADHD) is associated with substantial functional, clinical and economic burdens. It is among the most common psychiatric disorders in children and adolescents, and often persists into adulthood. Both medication and psychosocial interventions are recommended for the treatment of ADHD. However, ADHD treatment practices vary considerably, depending on medication availability, reimbursement and the evolution of clinical practice in each country. In Europe, stimulants and atomoxetine are widely available medications for the treatment of ADHD, whereas in the US approved treatment options also include extended-release formulations of clonidine and guanfacine. Lisdexamfetamine dimesylate (lisdexamfetamine) is a long-acting, prodrug formulation of dexamfetamine. It is currently licensed in the US, Canada and Brazil, and is undergoing phase III studies in Europe. We performed a PubMed/MEDLINE search looking for recent (2005-2012) scientific papers regarding the pharmacokinetics, pharmacodynamics, efficacy and safety of lisdexamfetamine. The lisdexamfetamine molecule is therapeutically inactive and is enzymatically hydrolysed, primarily in the blood, to the active dexamfetamine. This conversion is unaffected by gastrointestinal pH and variations in normal transit times. Lisdexamfetamine was developed with the goal of providing an extended duration of effect that is consistent throughout the day. Clinical trials have demonstrated robust clinical efficacy of lisdexamfetamine in the treatment of children, adolescents and adults with ADHD with dose-dependent improvements in the core symptoms of ADHD. Studies have further shown that the duration of action of lisdexamfetamine continues for 13 hours post-dosing in children and for 14 hours in adults. The tolerability profile of lisdexamfetamine is consistent with those of other stimulant medications, with decreased appetite, insomnia, abdominal pain and irritability among the more frequent treatment-emergent adverse events, most of which are mild to moderate in intensity and transient in nature. There are currently no parallel-group, head-to-head trial data comparing the efficacy and safety of lisdexamfetamine with other medications for ADHD. However, the available data, including a large effect size and consistent plasma concentrations throughout the day, suggest that lisdexamfetamine is a useful treatment option for patients with ADHD.

Temporal patterns of medications dispensed to children and adolescents in a national insured population

This study aimed to comprehensively describe prevalence and temporal dispensing patterns for medications prescribed to children and adolescents in the United States. Participants were 1.6 million children (49% female) under 18 years old enrolled in a nation-wide, employer-provided insurance plan. All medication claims from 1999–2006 were reviewed retrospectively. Drugs were assigned to 16 broad therapeutic categories. Effects of trend over time, seasonality, age and gender on overall and within category prevalence were examined. Results: Mean monthly prevalence for dispensed medications was 23.5% (range 19.4–27.5), with highest rates in winter and lowest in July. The age group with the highest prevalence was one-year-old children. On average each month, 17.1% of all children were dispensed a single drug and 6.4% were dispensed two or more. Over time, prevalence for two or more drugs did not change, but the proportion of children dispensed a single drug decreased (slope -.02%, p = .001). Overall, boys had higher monthly rates than girls (average difference 0.9%, p = .002). However, differences by gender were greatest during middle childhood, especially for respiratory and central nervous system agents. Contraceptives accounted for a large proportion of dispensed medication to older teenage girls. Rates for the drugs with the highest prevalence in this study were moderately correlated (average Pearson r.66) with those from a previously published national survey. Conclusion: On average, nearly one quarter of a population of insured children in the United States was dispensed medication each month. This rate decreased somewhat over time, primarily because proportionally fewer children were dispensed a single medication. The rate for two or more drugs dispensed simultaneously remained steady.

Management of attention-deficit/hyperactivity disorder: the importance of psychosocial and medication treatments

Attention-deficit/hyperactivity disorder (ADHD) assessment and treatment in children and adolescents is complex. Key biological and psychosocial risk factors need to be identified and treated because of their potential mediating interaction that affect the onset, progression, and psychosocial and medication treatment response of core ADHD symptoms and common associated co-morbid conditions. Both psychosocial and medication treatments, alone and in combination, have been shown to reduce the core ADHD symptoms and those of its key co-morbid disorders. Yet, to date, the potential synergism between targeted and specific medication and psychosocial treatments remains poorly understood and under-researched. Interestingly, recent positron emission tomography findings emphasise the importance of contextual salience and positive reinforcement strategies for stimulant medication, the primary medication treatment for ADHD, to have its effect. This is not surprising, given recent epigenetic models of gene-environment interaction that are revolutionising our understanding of developmental disorders like ADHD. This annotation briefly outlines the emerging evidence that supports the role of psychosocial treatment alongside medication treatment in the management of ADHD. Future significant clinical directions are noted.

A controlled trial of extended-release guanfacine and psychostimulants for attention-deficit/hyperactivity disorder

OBJECTIVE

To examine efficacy, tolerability, and safety of guanfacine extended release (GXR; ≤4 mg/d) adjunctive to a long-acting psychostimulant for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents 6 to 17 years of age with suboptimal, but partial, response to psychostimulant alone.

METHOD

In this multicenter, 9-week, double-blind, placebo-controlled, dose-optimization study, subjects (N = 461) continued their stable dose of psychostimulant given in the morning and were randomized to receive GXR in the morning (GXR AM), GXR in the evening (GXR PM), or placebo. Efficacy measures included ADHD Rating Scale IV (ADHD-RS-IV) and Clinical Global Impressions of Severity of Illness (CGI-S) and Improvement (CGI-I) scales. Safety measures included adverse events (AEs), vital signs, electrocardiograms, and laboratory evaluations.

RESULTS

At endpoint, GXR treatment groups showed significantly greater improvement from baseline ADHD-RS-IV total scores compared with placebo plus psychostimulant (GXR AM, p = .002; GXR PM, p < .001). Significant benefits of GXR treatment versus placebo plus psychostimulant were observed on the CGI-S (GXR AM, p = .013; GXR PM, p < .001) and CGI-I (GXR AM, p = .024; GXR PM, p = .003). At endpoint, small mean decreases in pulse, systolic, and diastolic blood pressure were observed in GXR treatment groups versus placebo plus psychostimulant. No new safety signals emerged following administration of GXR with psychostimulants versus psychostimulants alone. Most AEs were mild to moderate in severity.

CONCLUSIONS

Morning or evening GXR administered adjunctively to a psychostimulant showed significantly greater improvement over placebo plus psychostimulant in ADHD symptoms and generated no new safety signals. Clinical trial registration information-Efficacy and Safety of SPD503 in Combination With Psychostimulants; http://www.clinicaltrials.gov; NCT00734578.

Amfetamine and methylphenidate medications for attention-deficit/hyperactivity disorder: complementary treatment options

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders among school-aged children. It is highly symptomatic and associated with significant impairment. This review examines the role of stimulant medications in the treatment of children and adolescents with ADHD. Published clinical studies that compared methylphenidate- and amfetamine-based stimulants in children and adolescents with ADHD support the therapeutic utility of stimulant treatments, and suggest robust efficacy and acceptable safety outcomes in groups treated with either stimulant. Evidence-based guidelines agree that each patient with ADHD is unique and individual treatment strategies that incorporate both drug and non-drug treatment options should be sought. In seeking to optimize individual response and outcomes to stimulant therapy, important considerations include the selection of stimulant class, the choice of long- or short-acting stimulant formulations, addressing effectively any emergent adverse effects and strategies aimed at enhancing adherence to dosing regimen and persistence on therapy.

Atomoxetine in children and adolescents with attention-deficit/hyperactivity disorder. Systematic review of review papers 2009-2011. An update for clinicians

Attention deficit/hyperactivity disorder (ADHD) is a common disorder and a plethora of new data has been published from clinical trials and national epidemiological databases in the last three years. In the United Kingdom Atomoxetine is currently the only licensed non-stimulant medication. As part of a systematic review of atomoxetine data Jan 2009–June 2011 formal searches found 750 citations. From these 13 met criteria for either review or systematic review papers and contained clinical data synthesis on atomoxetine. No individual review paper alone would be sufficient for clinicians to be updated at that time on all clinical aspects of atomoxetine data. The crucial data relating to clinical parity of atomoxetine and methylphenidate in trials and meta-analysis where relevant confounding biases are removed are not often discussed. Systematic review of complex data is critical for ADHD clinicians and will need regular updating due to the large volume of new data.

Ningdong granule: a complementary and alternative therapy in the treatment of attention deficit/hyperactivity disorder

BACKGROUND

Attention deficit/hyperactivity disorder (ADHD) is a common neurobehavioral and neuropsychiatric disorder in school-age children, and recent studies provide evidence implicating the metabolic abnormalities of dopamine (DA) for its pathophysiology. Methylphenidate, a kind of psychostimulant, is widely used in the treatment of ADHD, but some patients do not respond to it or cannot bear its side effects. As a traditional Chinese medicine preparation, Ningdong granule (NDG) has been used in the treatment of ADHD for several years in China. However, a systematical pharmacological study on its safety and mechanism still remains obscure.

OBJECTIVE

This paper aims to evaluate the efficiency, safety, and possible mechanism of NDG on ADHD children compared to methylphenidate.

METHODS

Seventy-two ADHD children were recruited to perform an 8-week, randomized, methylphenidate-controlled, doubled-blinded trial. The subjects were equally assigned to two groups receiving either NDG 5 mg/kg/day or methylphenidate 1 mg/kg/day for 8 weeks. The efficiency was assessed by the Teacher and Parent ADHD Rating Scales every 2 weeks for a total of 8 weeks. The side effects were recorded during the study. Blood, urine, and stool routine samples, liver and renal function test, and DA and homovanillic acid (HVA) concentration in sera were tested at the beginning and end of the trial.

RESULTS

NDG ameliorated ADHD symptoms after an 8-week medication with fewer side effects compared to methylphenidate (P < 0.05). The result also showed NDG to be safe and tolerable for ADHD children as monitored by the blood, urine, and stool analysis and liver and renal function for 8 weeks (P < 0.05). Moreover, the level of HVA in sera increased in NDG-treated group (P < 0.05), while the content of DA had no significant change during the study. An analysis of Pearson correlation coefficients also showed that the increased content of HVA in sera was associated with the improved scores of Teacher and Parent ADHD Rating Scales.

CONCLUSIONS

Compared to methylphenidate, NDG is effective and safe for ADHD children in the short term, increases the HVA concentration in sera to regulate DA metabolism, and promises to be an alternative medication, safely and effectively.

Long-term outcomes with medications for attention-deficit hyperactivity disorder: current status of knowledge

Attention-deficit hyperactivity disorder (ADHD), a common neurobehavioural disorder characterized by inattention, hyperactivity and impulsivity, is a chronic disorder and often persists into adulthood. CNS stimulants have been the most well known treatment for ADHD for several decades due to their high effectiveness, good safety profiles and relatively minor adverse effects. Non-stimulant agents, including atomoxetine, extended-release guanfacine and extended-release clonidine (US FDA approved), and several non-FDA-approved agents, such as bupropion and tricyclic antidepressants (TCAs), were recently proven to be effective alternatives to the stimulants in several open-label and placebo-controlled trials. However, most medication trials for ADHD have been short term and thus have not provided information on the long-term outcomes of ADHD treatment. Since the medical treatment of many children with ADHD, especially those with more severe symptoms or co-morbid disorders, has to be continued for several years, recent studies have shifted their focus from the acute effectiveness of stimulants or non-stimulant drugs to the long-term outcomes of medications for ADHD. Evidence has shown that stimulants, along with the non-stimulants atomoxetine and extended-release guanfacine, are continuously effective for 24-month treatment periods with few and tolerable adverse effects.

Advances in understanding and treating ADHD

Attention deficit hyperactivity disorder (ADHD) is a neurocognitive behavioral developmental disorder most commonly seen in childhood and adolescence, which often extends to the adult years. Relative to a decade ago, there has been extensive research into understanding the factors underlying ADHD, leading to far more treatment options available for both adolescents and adults with this disorder. Novel stimulant formulations have made it possible to tailor treatment to the duration of efficacy required by patients, and to help mitigate the potential for abuse, misuse and diversion. Several new non-stimulant options have also emerged in the past few years. Among these, cognitive behavioral interventions have proven popular in the treatment of adult ADHD, especially within the adult population who cannot or will not use medications, along with the many medication-treated patients who continue to show residual disability.

Psychomotor functioning and alertness with guanfacine extended release in subjects with attention-deficit/hyperactivity disorder

OBJECTIVES

To determine whether treatment with guanfacine extended release (GXR) in subjects with attention-deficit/hyperactivity disorder (ADHD) disrupted psychomotor functioning and alertness, or impacted daytime sleepiness.

METHOD

This was a randomized, double-blind, placebo-controlled, multicenter, phase 2, dose-optimization, noninferiority, laboratory classroom study of GXR (1, 2, and 3 mg/day) in 182 subjects aged 6 to 17 years with ADHD. Psychomotor functioning and alertness were assessed through several measures, including the Choice Reaction Time (CRT) test from the Cambridge Neuropsychological Test Automated Battery. Sedative effects were examined via spontaneously reported adverse events of sedation, somnolence, and hypersomnia as well as fatigue and lethargy, and with two validated subject- and observer-rated sleepiness scales. Standard efficacy measures for ADHD also were included. Cardiovascular and laboratory parameters were assessed.

RESULTS

There were no significant differences between the GXR and placebo groups on measures of psychomotor functioning or alertness from the CRT at endpoint (least-square mean difference: 2.5 [95% confidence interval (CI): -22.9, 28.0], p = 0.8 for CRT; 2.5 [95% CI: -21.5, 26.4], p = 0.84 for correct responses; 15.5 [95% CI: -45.1, 14.1], p = 0.30 for movement time; and -8.2 [95% CI: -54.1, 37.6] p = 0.72 for total time). Most sedative adverse events were mild to moderate, occurred during dose titration, decreased with dose maintenance, and resolved during the study period. One subject in the GXR group discontinued due to fatigue and somnolence. GXR was not associated with increased daytime sleepiness. GXR treatment was associated with significant improvement in ADHD symptoms (6.3 [95% CI: 2.7, 9.8], p = 0.001 for ADHD Rating Scale IV total scores at endpoint).

CONCLUSIONS

At doses that resulted in significant improvement in ADHD symptoms, impairment on cognitive tasks was not observed. Daytime sleepiness did not differ with GXR compared with placebo. Results suggest that the beneficial effects of GXR on ADHD symptoms are independent of sedation.

Annual Research Review: New frontiers in developmental neuropharmacology: can long-term therapeutic effects of drugs be optimized through carefully timed early intervention?

Our aim is to present a working model that may serve as a valuable heuristic to predict enduring effects of drugs when administered during development. Our primary tenet is that a greater understanding of neurodevelopment can lead to improved treatment that intervenes early in the progression of a given disorder and prevents symptoms from manifesting. The immature brain undergoes significant changes during the transitions between childhood, adolescence, and adulthood. Such changes in innervation, neurotransmitter levels, and their respective signaling mechanisms have profound and observable changes on typical behavior, but also increase vulnerability to psychiatric disorders when the maturational process goes awry. Given the remarkable plasticity of the immature brain to adapt to its external milieu, preventive interventions may be possible. We intend for this review to initiate a discussion of how currently used psychotropic agents can influence brain development. Drug exposure during sensitive periods may have beneficial long-term effects, but harmful delayed consequences may be possible as well. Regardless of the outcome, this information needs to be used to improve or develop alternative approaches for the treatment of childhood disorders. With this framework in mind, we present what is known about the effects of stimulants, antidepressants, and antipsychotics on brain maturation (including animal studies that use more clinically-relevant dosing paradigms or relevant animal models). We endeavor to provocatively set the stage for altering treatment approaches for improving mental health in non-adult populations.

Performance deficits of NK1 receptor knockout mice in the 5-choice serial reaction-time task: effects of d-amphetamine, stress and time of day

Background

The neurochemical status and hyperactivity of mice lacking functional substance P-preferring NK1 receptors (NK1R-/-) resemble abnormalities in Attention Deficit Hyperactivity Disorder (ADHD). Here we tested whether NK1R-/- mice express other core features of ADHD (impulsivity and inattentiveness) and, if so, whether they are diminished by d-amphetamine, as in ADHD. Prompted by evidence that circadian rhythms are disrupted in ADHD, we also compared the performance of mice that were trained and tested in the morning or afternoon.

Methods and Results

The 5-Choice Serial Reaction-Time Task (5-CSRTT) was used to evaluate the cognitive performance of NK1R-/- mice and their wildtypes. After training, animals were tested using a long (LITI) and a variable (VITI) inter-trial interval: these tests were carried out with, and without, d-amphetamine pretreatment (0.3 or 1 mg/kg i.p.). NK1R-/- mice expressed greater omissions (inattentiveness), perseveration and premature responses (impulsivity) in the 5-CSRTT. In NK1R-/- mice, perseveration in the LITI was increased by injection-stress but reduced by d-amphetamine. Omissions by NK1R-/- mice in the VITI were unaffected by d-amphetamine, but premature responses were exacerbated by this psychostimulant. Omissions in the VITI were higher, overall, in the morning than the afternoon but, in the LITI, premature responses of NK1R-/- mice were higher in the afternoon than the morning.

Conclusion

In addition to locomotor hyperactivity, NK1R-/- mice express inattentiveness, perseveration and impulsivity in the 5-CSRTT, thereby matching core criteria for a model of ADHD. Because d-amphetamine reduced perseveration in NK1R-/- mice, this action does not require functional NK1R. However, the lack of any improvement of omissions and premature responses in NK1R-/- mice given d-amphetamine suggests that beneficial effects of this psychostimulant in other rodent models, and ADHD patients, need functional NK1R. Finally, our results reveal experimental variables (stimulus parameters, stress and time of day) that could influence translational studies.

Regulation of neuronal activation by Alpha2A adrenergic receptor agonist

Stress factors induce neuronal activation in brain areas that are related to anxiety and fear. High doses of caffeine induce neuronal activation with Ca2+ influx followed by expression of the immediate early gene c-fos. In the present study, we investigated c-Fos protein expression in stress-responsive brain areas induced by caffeine, as well as the role of alpha2A receptor in the regulation of neuronal activation. Immunohistochemical analysis showed that an acute effect of caffeine induced c-Fos protein expression in the hippocampus, the bed nucleus of stria terminalis (BNST), the lateral septum, the basolateral and central amygdala, the paraventricular hypothalamic nucleus (PVN), the locus coeruleus, and the lateral parabrachial nucleus (LPBN). However, c-Fos expression was attenuated after repeated treatment of caffeine, spaced 24 h apart, compared to a single acute effect. Alpha2A receptor activation with the agonist guanfacine attenuated the acute effect of caffeine in terms of c-Fos expression in neurons in the CA1-CA3 areas of hippocampus, the locus coeruleus and the LPBN as compared with effect of caffeine alone, whereas the number of c-Fos expressing neurons increased in the lateral septum, the dorsal BNST, the central amygdala, and the PVN, areas that are densely innervated by noradrenergic neurons. Guanfacine alone induced c-Fos protein expression in neurons in the central amygdala, the dorsal BNST, the PVN, the LPBN, and the caudal nucleus of the solitary tract. Guanfacine alone also induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in neurons expressing c-Fos in the dorsal BNST, the central amygdala, and the LPBN. These results suggest that alpha2A receptor activation modulates synaptic transmission in neuronal circuits that are correlated with stress in vivo.

Treatment stabilization in children and adolescents with attention-deficit/hyperactivity disorder: data from the Netherlands

OBJECTIVE

To evaluate the number of patients reaching stable treatment with a stimulant (methylphenidate or dexamphetamine) or non-stimulant (atomoxetine) attention-deficit/hyperactivity disorder (ADHD) medication approved for use in the Netherlands, and the time to treatment stabilization among children and adolescents aged 6-17 years.

RESEARCH DESIGN AND METHODS

Prescription data from the PHARMO medical record linkage system from 48 geo-demographic areas in the Netherlands (2003-2006) were analyzed from newly treated patients with ADHD aged 6-17 years. Only patients with ≥ 5 dispensings for any ADHD drug during follow-up (at least 12 months) and no missing information on type of drug, strength, and number of pills per day were included.

MAIN OUTCOME MEASURES

Attainment of a stable dosing regimen was defined as no change in type of drug (including a switch from an immediate release (IR) to a long-acting (LA) formulation), strength, and number of pills per day for five consecutive dispensings. Time to stable dosing regimen was defined as the number of days between the first dispensing for an ADHD drug and the first of five unchanged dispensings.

RESULTS

Of 4909 children or adolescents initiating treatment, 3099 met selection criteria. More patients starting therapy with LA methylphenidate (82.4%) achieved treatment stabilization during follow-up than with IR methylphenidate (74.8%; p < 0.01) or atomoxetine (69.8%; p < 0.05). More patients initiated on LA methylphenidate patients (43.9%) achieved treatment stabilization without changing their index medication or dose compared to those initiated on IR methylphenidate (25.3%) or atomoxetine (8.1%; p < 0.0001 for both comparisons). Among patients achieving treatment stabilization, those initiating treatment with LA methylphenidate had a significantly shorter time to treatment stabilization (14 days) than patients initially treated with IR methylphenidate (56 days; p < 0.001) or atomoxetine (31 days; p < 0.05). Mean number of pills per day varied between 1.0 and 1.8 at initial treatment and 1.1 and 1.9 at treatment stabilization. Potential limitations of the study include the use of ADHD-medication dispensing as a proxy for an ADHD diagnosis and the impact of different titration schedules for the various ADHD medications.

CONCLUSION

Overall, 2316 of the 3066 eligible patients (75.5%) achieved treatment stabilization during follow-up. Among children and adolescents with ADHD in the Netherlands, the time to treatment stabilization varied according to choice of initial treatment and was shortest for LA methylphenidate.