Development of a novel rodent rapid serial visual presentation task reveals dissociable effects of stimulant versus nonstimulant treatments on attentional processes.

The rapid serial visual presentation (RSVP) task and continuous performance tasks (CPT) are used to assess attentional impairments in patients with psychiatric and neurological conditions. This study developed a novel touchscreen task for rats based on the structure of a human RSVP task and used pharmacological manipulations to investigate their effects on different performance measures. Normal animals were trained to respond to a target image and withhold responding to distractor images presented within a continuous sequence. In a second version of the task, a false-alarm image was included, so performance could be assessed relative to two types of nontarget distractors. The effects of acute administration of stimulant and nonstimulant treatments for ADHD (amphetamine and atomoxetine) were tested in both tasks. Methylphenidate, ketamine, and nicotine were tested in the first task only. Amphetamine made animals more impulsive and decreased overall accuracy but increased accuracy when the target was presented early in the image sequence. Atomoxetine improved accuracy overall with a specific reduction in false-alarm responses and a shift in the attentional curve reflecting improved accuracy for targets later in the image sequence. However, atomoxetine also slowed responding and increased omissions. Ketamine, nicotine, and methylphenidate had no specific effects at the doses tested. These results suggest that stimulant versus nonstimulant treatments have different effects on attention and impulsive behaviour in this rat version of an RSVP task. These results also suggest that RSVP-like tasks have the potential to be used to study attention in rodents.

Medication Use in the Management of Comorbidities Among Individuals With Autism Spectrum Disorder From a Large Nationwide Insurance Database.

Importance: Although there is no pharmacological treatment for autism spectrum disorder (ASD) itself, behavioral and pharmacological therapies have been used to address its symptoms and common comorbidities. A better understanding of the medications used to manage comorbid conditions in this growing population is critical; however, most previous efforts have been limited in size, duration, and lack of broad representation. Objective: To use a nationally representative database to uncover trends in the prevalence of co-occurring conditions and medication use in the management of symptoms and comorbidities over time among US individuals with ASD. Design, Setting, and Participants: This retrospective, population-based cohort study mined a nationwide, managed health plan claims database containing more than 86 million unique members. Data from January 1, 2014, to December 31, 2019, were used to analyze prescription frequency and diagnoses of comorbidities. A total of 26 722 individuals with ASD who had been prescribed at least 1 of 24 medications most commonly prescribed to treat ASD symptoms or comorbidities during the 6-year study period were included in the analysis. Exposures: Diagnosis codes for ASD based on International Classification of Diseases, Ninth Revision, and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision. Main Outcomes and Measures: Quantitative estimates of prescription frequency for the 24 most commonly prescribed medications among the study cohort and the most common comorbidities associated with each medication in this population. Results: Among the 26 722 individuals with ASD included in the analysis (77.7% male; mean [SD] age, 14.45 [9.40] years), polypharmacy was common, ranging from 28.6% to 31.5%. Individuals' prescription regimens changed frequently within medication classes, rather than between classes. The prescription frequency of a specific medication varied considerably, depending on the coexisting diagnosis of a given comorbidity. Of the 24 medications assessed, 15 were associated with at least a 15% prevalence of a mood disorder, and 11 were associated with at least a 15% prevalence of attention-deficit/hyperactivity disorder. For patients taking antipsychotics, the 2 most common comorbidities were combined type attention-deficit/hyperactivity disorder (11.6%-17.8%) and anxiety disorder (13.1%-30.1%). Conclusions and Relevance: This study demonstrated considerable variability and transiency in the use of prescription medications by US clinicians to manage symptoms and comorbidities associated with ASD. These findings support the importance of early and ongoing surveillance of patients with ASD and co-occurring conditions and offer clinicians insight on the targeted therapies most commonly used to manage co-occurring conditions. Future research and policy efforts are critical to assess the extent to which pharmacological management of comorbidities affects quality of life and functioning in patients with ASD while continuing to optimize clinical guidelines, to ensure effective care for this growing population.

Pharmacotherapy of attention deficit/hyperactivity disorder in individuals with autism spectrum disorder: A systematic review of the literature.

AIM: To assess the empirical evidence for the treatment of attention deficit/hyperactivity disorder (ADHD) in populations with autism spectrum disorder (ASD). METHODS: A systemic PubMed, PsychINFO, Embase, and Medline database search of peer-reviewed literature was conducted. Included in the review were controlled trials published in English with sample sizes ⩾10 participants examining the safety and efficacy of anti-ADHD medication in ASD populations. Data was extracted on relevant variables of study design, demographics, associated psychopathology, medication dose, efficacy, and tolerability. RESULTS: Nine controlled trials met the inclusion and exclusion criteria: five with methylphenidate, three with atomoxetine, and one with guanfacine. Sample sizes ranged from 10 to 128 with 430 children participating across all the trials. In all the trials, treatment response was significantly superior to placebo. However, almost all trials assessed only hyperactivity, and most included only participants with intellectual disability with high levels of irritability. None of the trials distinguished agitation from hyperactivity. The response on hyperactivity for methylphenidate and atomoxetine was less than that observed in the neurotypical population; however, the response for guanfacine surpassed results observed in neurotypical populations. Treatment-emergent mood lability (i.e. mood dysregulation and mood-related adverse events) was frequently associated with methylphenidate and guanfacine treatments. Worse treatment outcomes were associated with individuals with lower intellectual capability compared with those with higher IQs. CONCLUSIONS: here is a scarcity of controlled trials examining ADHD treatments in ASD populations, particularly in intellectually capable individuals with ASD and in adults. Response to ADHD medications in ASD were adversely moderated by the presence of intellectual disability and mood lability.

Investigation of serum and brain superoxide dismutase levels depending on atomoxetine used in attention-deficit/hyperactivity disorder treatment: A combination of in vivo and molecular docking studies.

This study aims to determine whether atomoxetine (ATX), used as an alternative to methylphenidate, affects superoxide dismutase (SOD) activity besides glutathione (GSH) and malondialdehyde (MDA) levels, apart from determining possible effects of ATX on SOD activity through molecular docking studies. 24 male Wistar rats were divided into 4 groups, each containing 6 members. After a 6-week application of ATX, blood samples and brain tissues were obtained from the rats for biochemical analyses. Besides, molecular docking studies were conducted using PyRx and Discovery Studio 3.0 programs. No significant difference occurred in GSH and MDA levels after ATX application. A high-dose application of ATX caused a statistically significant change only in the serum-SOD activity compared to that of Control Group. Molecular docking studies revealed that ATX settled in the biggest space rather than the catalytic regions of Cu2Zn2-SOD. Our biochemical and molecular docking data showed that ATX, an alternative drug to stimulant methylphenidate, showed no significant changes in the antioxidant defence system at either low or therapeutic doses after long-term use. Therefore, we suggest ATX could be used as a substitute for methylphenidate in the long-term treatment of ADHD.

Effects of paroxetine on the pharmacokinetics of atomoxetine and its metabolites in different CYP2D6 genotypes.

The aim of this study was to investigate the effects of paroxetine, a potent inhibitor of CYP2D6, on the pharmacokinetics of atomoxetine and its two metabolites, 4-hydroxyatomoxetine and N-desmethylatomoxetine, in different CYP2D6 genotypes. Twenty-six healthy subjects were recruited and divided into CYP2D6*wt/*wt (*wt=*1 or *2, n = 10), CYP2D6*wt/*10 (n = 9), and CYP2D6*10/*10 groups (n = 7). In atomoxetine phase, all subjects received a single oral dose of atomoxetine (20 mg). In paroxetine phase, after administration of a single oral dose of paroxetine (20 mg) for six consecutive days, all subjects received a single oral dose of atomoxetine with paroxetine. Plasma concentrations of atomoxetine and its metabolites were determined up to 24 h after dosing. During atomoxetine phase, there were significant differences in Cmax and AUC0-24 of atomoxetine and N-desmethylatomoxetine among three genotype groups, whereas significant differences were not found in relation to CYP2D6*10 allele after administration of paroxetine. AUC ratios of 4-hydroxyatomoxetine and N-desmethylatomoxetine to atomoxetine were significantly different among three genotype groups during atomoxetine phase (all, P < 0.001), but after paroxetine treatment significant differences were not found. After paroxetine treatment, AUC0-24 of atomoxetine was increased by 2.3-, 1.7-, and 1.3-fold, in CYP2D6*wt/*wt, CYP2D6*wt/*10, and CYP2D6*10/*10 groups in comparison to atomoxetine phase, respectively. AUC ratio of 4-hydroxyatomoxetine to atomoxetine in each group was significantly decreased, whereas AUC ratio of N-desmethylatomoxetine to atomoxetine significantly increased after administration of paroxetine. In conclusion, paroxetine coadministration significantly affected pharmacokinetic parameters of atomoxetine and its two metabolites, 4-hydroxyatomoxetine and N-desmethylatomoxetine. When atomoxetine was administered alone, Cmax, AUC0-24 and CL/F of atomoxetine were significantly different among the three CYP2D6 genotype groups. However, after paroxetine coadministration, no significant differences in these pharmacokinetic parameters were observed among the CYP2D6 genotype groups.

Different effects of methylphenidate and atomoxetine on the behavior and brain transcriptome of zebrafish.

Attention deficit-hyperactivity disorder (ADHD) is a prevalent neuropsychiatric disorder found in children. It is characterized by inattention, hyperactivity, and impulsivity. Methylphenidate (MPH) and atomoxetine (ATX) are commonly prescribed for the treatment of ADHD. In the present study, we examined the behavioral and brain transcriptome changes in MPH-treated and ATX-treated zebrafish. In behavioral analysis, zebrafish showed opposite response to each treatment. MPH-treated fish showed higher anxiety-like behavior while ATX-treated fish showed lower anxiety-like behavior. Further, we performed RNA sequencing analysis of zebrafish brain to elucidate the underlying biological pathways associated with MPH and ATX treatment. Interestingly, we found that shared differentially expressed genes in MPH-treated and ATX-treated fish were instrumental in cholesterol biosynthesis pathway and were regulated in opposite manner. Our findings highlight the contrast between MTH and ATX, and may suggest the alterations in clinical practice for these medications and drug development for ADHD.

The effects of medication on intraocular pressure in children with attention deficit hyperactivity disorder: A prospective study.

Attention deficit hyperactivity disorder (ADHD) is one of the most common psychiatric conditions in childhood. Psychopharmacological therapy is an effective treatment for ADHD. In this study, we primarily aim to investigate the effects of psychopharmacological agents on intraocular pressure (IOP) in children with ADHD. The sample included 82 children with ADHD and 36 healthy children aged between 8 and 12 years who were referred to the Department of Child and Adolescent Psychiatry in Hatay State Hospital, Hatay, Turkey. Children with ADHD were divided into two groups according to the medication used: methylphenidate (MPH) group and atomoxetine (ATX) group. Before treatment and after 1- and 6-month treatment period, IOP was measured by Goldmann applanation tonometry. There were no statistical differences in terms of age, gender, and IOP between the three groups (P > 0.05). After 1- and 6-month treatment, the IOP did not change significantly between baseline and 1 month or 6 months (P > 0.05). Children with ADHD may have an IOP similar to healthy children. Six-month treatment with MPH or ATX may not cause significant changes in IOP.

Taste masking of water-soluble drug by solid lipid microspheres: a child-friendly system established by reversed lipid-based nanoparticle technique.

OBJECTIVES: A child-friendly taste-masking strategy using solid lipid microsphere (SLM) has been proposed to obscure the undesirable taste of some water-soluble drugs. In this study, the reversed lipid-based nanoparticle (RLBN) technique was used to encapsulate a water-soluble drug to facilitate the preparation of SLM. METHODS: The model drug used was atomoxetine hydrochloride (ATX), and a three-step method was used to prepare ATX-RLBN. Taste-masking microsphere (ATX-RLBN-SLM) was prepared by the spray chilling method. The drug release mechanism was studied by high-performance liquid chromatography and scanning electron microscopy. Moreover, in vitro taste evaluation method was established and ATX bioavailability was investigated employing pharmacokinetic studies. KEY FINDINGS: The obtained ATX-RLBN-SLM had smooth spherical particles with a size of about 80 µm. The drug encapsulation and loading efficiencies were 98.28% ± 0.59% and 0.89% ± 0.04%, respectively. In vitro drug release studies showed that nearly 96% drug was retained in the microspheres within 10 min at pH 6.8 and a complete release was triggered by lipase, accompanied by variation in the morphology. Taste assessment revealed that ATX-RLBN-SLM could efficiently mask the bitter taste and improved the bioavailability of ATX. CONCLUSIONS: Atomoxetine hydrochloride-reversed lipid-based nanoparticle-solid lipid microsphere exhibited excellent taste-masking effect with negligible leakage in the oral cavity environment and thorough collapse upon lipase stimulation, simultaneously enhancing the bioavailability of ATX. The study paves a new way to efficiently mask the undesirable taste of some water-soluble drugs.

Diagnosis and Treatment Options for Preschoolers with Attention-Deficit/Hyperactivity Disorder.

Objective: The Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), classifies attention-deficit/hyperactivity disorder (ADHD) as a neurodevelopmental disorder, with symptoms becoming apparent as early as the preschool years. Early recognition can lead to interventions such as parent/teacher-administered behavior therapy, the recommended first-line treatment for preschool patients. There are few data, however, to inform the use of second-line, pharmacotherapy options in this population. In this review, we identified recent literature on the diagnosis and treatment of ADHD in preschool children. Methods: A PubMed and clinicaltrials.gov search was conducted for trials assessing efficacy or safety of ADHD medications in children aged <6 years. Diagnostic methods and criteria focusing on recognition of ADHD in preschool children were also surveyed. Results: The DSM-5 describes different manifestations of ADHD in preschool versus school-aged children, but does not list separate criteria by age group. Importantly, behaviors indicative of ADHD in older children may be developmentally appropriate in preschool children. Several behavioral rating scales have been validated in children younger than 6 years of age for assessing ADHD. The Preschool ADHD Treatment Study (PATS) has provided the most extensive efficacy and safety data on methylphenidate (MPH) for ADHD in preschoolers to date, with significant improvement in ADHD symptoms observed with MPH compared with placebo, although adverse event-related discontinuation was higher in PATS compared with studies of MPH for ADHD in school-aged children. Since PATS was conducted, few studies designed to assess ADHD medication effectiveness in preschool children have been published. One article reported significant improvement in ADHD symptoms with MPH (immediate release) versus placebo, two studies showed no difference between MPH and risperidone or MPH plus risperidone in relief of ADHD symptoms, and one study demonstrated the efficacy of atomoxetine versus placebo for ADHD symptoms in preschoolers. Conclusions: Further research is needed on pharmacotherapy for preschool children with ADHD.

Tailoring Atomoxetine Release Rate from DLP 3D-Printed Tablets Using Artificial Neural Networks: Influence of Tablet Thickness and Drug Loading.

Various three-dimensional printing (3DP) technologies have been investigated so far in relation to their potential to produce customizable medicines and medical devices. The aim of this study was to examine the possibility of tailoring drug release rates from immediate to prolonged release by varying the tablet thickness and the drug loading, as well as to develop artificial neural network (ANN) predictive models for atomoxetine (ATH) release rate from DLP 3D-printed tablets. Photoreactive mixtures were comprised of poly(ethylene glycol) diacrylate (PEGDA) and poly(ethylene glycol) 400 in a constant ratio of 3:1, water, photoinitiator and ATH as a model drug whose content was varied from 5% to 20% (w/w). Designed 3D models of cylindrical shape tablets were of constant diameter, but different thickness. A series of tablets with doses ranging from 2.06 mg to 37.48 mg, exhibiting immediate- and modified-release profiles were successfully fabricated, confirming the potential of this technology in manufacturing dosage forms on demand, with the possibility to adjust the dose and release behavior by varying drug loading and dimensions of tablets. DSC (differential scanning calorimetry), XRPD (X-ray powder diffraction) and microscopic analysis showed that ATH remained in a crystalline form in tablets, while FTIR spectroscopy confirmed that no interactions occurred between ATH and polymers.

Dopamine and norepinephrine transporter inhibition for long-term fear memory enhancement.

Psychostimulants are highly effective cognitive-enhancing therapeutics yet have a significant potential for abuse and addiction. While psychostimulants likely exert their rewarding and addictive properties through dopamine transporter (DAT) inhibition, the mechanisms of their procognitive effects are less certain. By one prevalent view, psychostimulants exert their procognitive effects exclusively through norepinephrine transporter (NET) inhibition, however increasing evidence suggests that DAT also plays a critical role in their cognitive-enhancing properties, including long-term memory enhancement. The present experiments test the hypothesis that combined strong NET and weak DAT inhibition will mimic the fear memory-enhancing but not the addiction-related effects of psychostimulants in mice. We examined the effects of the high affinity NET inhibitors atomoxetine or nisoxetine and the low affinity DAT inhibitor bupropion, either alone or in combination, on short- and long-term memory of Pavlovian fear conditioning. We also examined the addiction-related effects of combined strong NET and weak DAT inhibition using conditioned place preference and a locomotor activity test. While atomoxetine or nisoxetine alone enhanced short-term fear memory, the addition of bupropion was required to significantly enhance long-term fear memory. Additionally, combined atomoxetine and bupropion did not produce substantial motor stimulation or place preference. These findings suggest that combining strong NET and weak DAT inhibition could lead to the development of a highly effective cognitive enhancer that lacks the potential for addiction.

Efficacy of atomoxetine versus midodrine for neurogenic orthostatic hypotension.

OBJECTIVE: The efficacy and safety of 1-month atomoxetine and midodrine therapies were compared. Three-month atomoxetine and combination therapies were investigated for additional benefits. METHODS: This prospective open-label randomized trial included 50 patients with symptomatic neurogenic orthostatic hypotension (nOH). The patients received either atomoxetine 18 mg daily or midodrine 5 mg twice daily and were evaluated 1 and 3 months later. Those who still met the criteria for nOH at 1 month received both midodrine and atomoxetine for an additional 2 months, and if not, they continued their initial medication. The primary outcome was an improvement in orthostatic blood pressure (BP) drop (maximum BP change from supine to 3 min after standing) at 1 month. The secondary endpoints were symptom scores, percentage of patients with nOH at 1 and 3 months. RESULTS: Patients with midodrine or atomoxetine treatment showed comparative improvement in the orthostatic BP drop, and overall only 26.2% of the patients had nOH at 1 month, which was similar between the treatment groups. Only atomoxetine resulted in significant symptomatic improvements at 1 month. For those without nOH at 1 month, there was additional symptomatic improvement at 3 months with their initial medication. For those with nOH at 1 month, the combination treatment resulted in no additional improvement. Mild-to-moderate adverse events were reported by 11.6% of the patients. INTERPRETATION: One-month atomoxetine treatment was effective and safe in nOH patients. Atomoxetine improved orthostatic BP changes as much as midodrine and was better in terms of ameliorating nOH symptoms.

Atomoxetine Efficacy in Methamphetamine Dependence during Methadone Maintenance Therapy.

BACKGROUND: Co-occurring methamphetamine (METH) use during methadone maintenance therapy (MMT) is a highly prevalent and progressive problem in Iran. There are no registered pharmacological treatments for treating METH use disorder. The present study investigates the potential efficacy of atomoxetine in the treatment of these patients. METHODS: In a double-blind, controlled clinical trial, 86 METH-dependents on MMT randomly received either atomoxetine (40 mg/d) or placebo. We measured the craving scores with visual analog scale (VAS) on a weekly basis, and evaluated depression, anxiety and stress with the Depression Anxiety Stress Scales (DASS) on a monthly basis. Measurements were made in each weekly visit with urinary METH drug test. RESULTS: Atomoxetine significantly reduced METH craving (P < 0.001). Negative METH urine test increased significantly in the drug group compared to the placebo group (P = 0.007). While initially the METH urine test was positive for all patients, 56% (25/45) in the atomoxetine group and 26% (11/41) in the placebo group had negative METH urine tests after 8 weeks. DASS were decreased in both groups with a greater reduction in the atomoxetine group [depression (P = 0.028), anxiety (P = 0.038), and stress (P = 0.031)]. Only mild side effects were observed. CONCLUSION: This study confirms the safety and clinical tolerance of atomoxetine, and its appropriate efficacy in suppressing METH craving and possible potential effects on its treatment.

A proof of principle study of atomoxetine for the prevention of vasovagal syncope: the Prevention of Syncope Trial VI.

AIMS: There are few effective therapies for vasovagal syncope (VVS). Pharmacological norepinephrine transporter (NET) inhibition increases sympathetic tone and decreases tilt-induced syncope in healthy subjects. Atomoxetine is a potent and highly selective NET inhibitor. We tested the hypothesis that atomoxetine prevents tilt-induced syncope. METHODS AND RESULTS: Vasovagal syncope patients were given two doses of study drug [randomized to atomoxetine 40 mg (n = 27) or matched placebo (n = 29)] 12 h apart, followed by a 60-min drug-free head-up tilt table test. Beat-to-beat heart rate (HR), blood pressure (BP), and cardiac haemodynamics were recorded using non-invasive techniques and stroke volume modelling. Patients were 35 ± 14 years (73% female) with medians of 12 lifetime and 3 prior year faints. Fewer subjects fainted with atomoxetine than with placebo [10/29 vs. 19/27; P = 0.003; risk ratio 0.49 (confidence interval 0.28-0.86)], but equal numbers of patients developed presyncope or syncope (23/29 vs. 21/27). Of patients who developed only presyncope, 87% (13/15) had received atomoxetine. Patients with syncope had lower nadir mean arterial pressure than subjects with only presyncope (39 ± 18 vs. 69 ± 18 mmHg, P < 0.0001), and this was due to lower trough HRs in subjects with syncope (67 ± 30 vs. 103 ± 32 b.p.m., P = 0.006) and insignificantly lower cardiac index (2.20 ± 1.36 vs. 2.84 ± 1.05 L/min/m2, P = 0.075). There were no significant differences in stroke volume index (32 ± 6 vs. 35 ± 5 mL/m2, P = 0.29) or systemic vascular resistance index (2156 ± 602 vs. 1790 ± 793 dynes*s/cm5*m2, P = 0.72). CONCLUSION: Norepinephrine transporter inhibition significantly decreased the risk of tilt-induced syncope in VVS subjects, mainly by blunting reflex bradycardia, thereby preventing final falls in cardiac index and BP.

Cost of ADHD treatment using methylphenidate and atomoxetine in the South African private healthcare sector.

Introduction: The prevalence of Attention-Deficit/Hyperactivity Disorder (ADHD) has risen over the last two decades, with a corresponding increase in the cost of its medication. Drug utilization studies in South Africa focusing on ADHD are limited.Areas covered: The primary aim was to determine the cost of methylphenidate and atomoxetine (used for ADHD). The Intercontinental Marketing Service (IMS) database which contains data of the private healthcare sector was interrogated from 2013 to 2016 (48-month period) focussing on methylphenidate and atomoxetine. Drug consumption was expressed in number of DDDs, DDDs/1000 inhabitants/day and cost in Rands.Expert opinion: Methylphenidate-containing products constituted a considerably higher percentage of the market share when compared to atomoxetine (90.30% versus 9.70%). The DDD/1000 inhabitants/day for methylphenidate was 6.010 with an annual cost for R266 691 778 in 2013, which increased to 7.827 DDDs/1000 inhabitants/day with an annual cost of R436 041 506 in 2016. Consumption of both methylphenidate and atomoxetine increased from 2013 to 2016. There was a preference for long-acting extended-release methylphenidate tablets even though the unit costs were higher when compared to the short-acting formulations. Despite increases in unit costs, the spend in South Africa showed an upward trend for methylphenidate and atomoxetine.

Acute Atomoxetine Selectively Modulates Encoding of Reward Value in Ventral Medial Prefrontal Cortex.

BACKGROUND: A recent neurocognitive model of attention-deficit hyperactivity disorder (ADHD) has proposed a primary deficit in reward function as well as in executive function to account for underlying neural substrates of ADHD symptoms. Atomoxetine has been widely used as a non-stimulant medication for ADHD with little abuse liability. Although animal studies have reported that atomoxetine increases extracellular levels of both noradrenaline and dopamine in the prefrontal cortex, which receives input from a mesocorticolimbic pathway involved in reward function, there have been few studies in humans concerning the effects of atomoxetine in terms of reward function. Therefore, we investigated whether a single dose of atomoxetine (acute atomoxetine) affects reward processing in healthy adults. METHODS: We used functional magnetic resonance imaging and adopted the monetary incentive delay task to separately examine neural responses to monetary reward anticipation in the nucleus accumbens and outcome in the ventral medial prefrontal cortex (vmPFC). The experiment was designed as a randomized, placebo-controlled within-subjects cross-over trial. Fourteen healthy adults completed two series of studies, taking either atomoxetine or placebo. RESULTS: Atomoxetine significantly decreased vmPFC activation during gain outcome compared to placebo. In gain anticipation, however, atomoxetine did not show a significant increase in the nucleus accumbens activation compared with placebo. CONCLUSIONS: These results suggest that atomoxetine affects reward value encoding through selective modulation of vmPFC activity related to reward outcome. Therefore, such modulatory action may partly contribute to a therapeutic effect of atomoxetine for a group of ADHD patients with increased activity in vmPFC.