Atomoxetine produces oxidative stress and alters mitochondrial function in human neuron-like cells

Medications for attention deficit hyperactivity disorder associated with increased risk of developing glaucoma

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) therapies including atomoxetine, methylphenidate, and amphetamines are some of the most prescribed medications in North America. Due to their sympathomimetic action, these drugs are contraindicated in patients with a history of angle closure glaucoma (ACG). This study aims to determine the risk of ACG and open angle glaucoma (OAG) among users of these treatments.

METHODS

This is a retrospective cohort study with a case control analysis using the PharMetrics Plus Database (IQVIA, USA). We created a cohort of new users of atomoxetine, methylphenidate, and amphetamines and they were followed to the first diagnosis of (1) ACG or OAG; or (2) end of follow up. For each case, four age-matched controls were selected. A conditional logistic regression model was used to adjust for confounders and to calculate adjusted incidence-rate-ratios (aIRRs).

RESULTS

A total of 240,257 new users of the ADHD medications were identified. The mean age was 45.0 ± 19.4 years and 55% of the cohort was female. Regular users of atomoxetine and amphetamines had a higher aIRR for developing ACG compared with non-users (aIRR = 2.55 95% CI [1.20-5.43] and 2.27 95% CI [1.42-3.63], respectively); while users of methylphenidate had a higher aIRR for developing OAG (aIRR = 1.23 95% CI [1.05-1.59]).

CONCLUSIONS

Use of amphetamines and atomoxetine had a higher risk for ACG, while use of methylphenidate was associated with a higher risk for OAG. Given the prevalence of ADHD medication use (medically and recreationally), our current data on their associated risk of glaucoma have profound public health implications.

Fountain of youth—Targeting autophagy in aging

As our society ages inexorably, geroscience and research focusing on healthy aging is becoming increasingly urgent. Macroautophagy (referred to as autophagy), a highly conserved process of cellular clearance and rejuvenation has attracted much attention due to its universal role in organismal life and death. Growing evidence points to autophagy process as being one of the key players in the determination of lifespan and health. Autophagy inducing interventions show significant improvement in organismal lifespan demonstrated in several experimental models. In line with this, preclinical models of age-related neurodegenerative diseases demonstrate pathology modulating effect of autophagy induction, implicating its potential to treat such disorders. In humans this specific process seems to be more complex. Recent clinical trials of drugs targeting autophagy point out some beneficial effects for clinical use, although with limited effectiveness, while others fail to show any significant improvement. We propose that using more human-relevant preclinical models for testing drug efficacy would significantly improve clinical trial outcomes. Lastly, the review discusses the available cellular reprogramming techniques used to model neuronal autophagy and neurodegeneration while exploring the existing evidence of autophagy’s role in aging and pathogenesis in human-derived in vitro models such as embryonic stem cells (ESCs), induced pluripotent stem cell derived neurons (iPSC-neurons) or induced neurons (iNs).

Atomoxetine Decreases Mitochondrial Biogenesis, Fission and Fusion In Human Neuron-like Cells But Does Not Alter Antioxidant Defences

Atomoxetine (ATX) is a presynaptic norepinephrine transporter (NET) inhibitor widely prescribed for attention-deficit/hyperactivity disorder (ADHD) due to its low abuse potential and absence of psychostimulant effects. While NET inhibition is implicated in the clinical response, several additional pharmacoactivities may contribute to clinical efficacy or unwanted side effects. We recently reported that ATX can dose-dependently alter mitochondrial function and cellular redox status. Here, we assessed potential alterations in mitochondrial biogenesis, mitochondrial dynamics and cellular antioxidant capacity following high- and low-dose ATX treatment of differentiated human neuroblastoma cells. Human SH-SY5Y neuroblastoma cells were treated with ATX (1, 5, 10, 20 and 50 μM) for 7 days under differentiation culture conditions. Changes in the expression levels of protein markers for mitochondrial biogenesis, fusion and fission as well as of antioxidant proteins were analysed by Western blot. High-dose ATX (50 μM) reduced while low-dose ATX (10 μM) increased mitochondrial biogenesis as evidenced by parallel changes in SDHA, COX-I, PGC1α and TFAM expression. High-dose ATX also reduced mitochondrial fusion as evidenced by OPA1 and MFN2 downregulation, and mitochondrial fission as indicated by DRP1 and Fis1 downregulation. In contrast, ATX did not alter expression of the antioxidant enzymes SOD1 and catalase, the phase II transcription factor Nfr2, or the Nfr2-regulated antioxidant enzyme NQO1. Clinical responses and side effects of ATX may be mediated by dose-dependent modulation of mitochondrial biogenesis and dynamics as well as NET inhibition.

Kainate receptor subunit 1 (GRIK1) risk variants and GRIK1 deficiency were detected in the Indian ADHD probands

Executive dysfunctions caused by structural and functional abnormalities of the prefrontal cortex were reported in patients with Attention deficit hyperactivity disorder (ADHD). Owing to a higher expression of the glutamate ionotropic receptor kainate type subunit 1 (GluK1), encoded by the GRIK1 gene, in brain regions responsible for learning and memory, we hypothesized that GRIK1 might have a role in ADHD. GRIK1 variants rs363504 and rs363538, affecting the receptor function, were analyzed by case-control and family-based methods to identify the association with ADHD. The impact of these variants on ADHD-associated traits and pharmacological intervention were also analyzed. GRIK1 expression was quantified in the peripheral blood. The probands and their fathers had a higher frequency of rs363504 'CC' and rs363538 'CA' genotypes. Family-based investigation revealed maternal over transmission of rs363504 'C' and rs363538 'A' alleles to the probands. Quantitative trait analysis exhibited an association of rs363504 'TT' and rs363538 'AA' genotypes with higher hyperactivity scores of the probands. In the presence of rs363504 'TT' and rs363538 'CC' genotypes, MPH treatment improved hyperactivity and inattention, respectively. GRIK1 expression was significantly downregulated in the probands. We infer that GRIK1 affects ADHD etiology, warranting further in-depth investigation involving a larger cohort and more functional variants.

Effect of Atomoxetine on Behavioral Difficulties and Growth Development of Primary School Children with Attention-Deficit/Hyperactivity Disorder: A Prospective Study

(1) Objective: Atomoxetine is a selective norepinephrine reuptake inhibitor used to treat attention-deficit/hyperactivity disorder (ADHD) in children over six years old. Although it is common knowledge that primary school children with ADHD often present with difficulties in the morning prior to school and in the evening, these two periods, and the family interactions they involve, are often neglected in studies of ADHD. Questionnaire–Children with Difficulties (QCD) has been widely used in China to evaluate parents’ perceptions of ADHD and patients’ daily behaviors during different times. In the long term, the efficacy and safety of atomoxetine have been well established in previous studies. Still, the short-term effects of atomoxetine treatment on serum growth parameters, such as IGF-1, IGFBP-3, and thyroid function, are not well documented. Therefore, this study was the first one using the QCD to quantify the efficacy of atomoxetine treatment in the morning prior to school and in the evening, and has investigated the possible influence on the growth parameters of Chinese primary school children with ADHD. (2) Method: This prospective study was conducted at the Department of Pediatrics at the Affiliated Hospital of Jiangnan University from August 2019 to February 2021. Changes in the children’s behavior and core ADHD symptoms following treatment were assessed using three parent-reported questionnaires, including Children with Difficulties (QCD), the Swanson, Nolan, and Pelham IV scale (SNAP-IV), and the Conners’ parents rating scales (CPRS). The height, weight, and body mass index (BMI) were measured and corrected to reflect the standard deviations (SDS) in Chinese children based on age and gender. Serum growth parameters, such as insulin-like growth factor 1 (IGF-1), insulin-like growth factor-binding protein 3 (IGFBP-3), and thyroid function, were also measured to assess the children’s growth development. Any adverse drug reactions were assessed every three weeks. (3) Result: Finally, 149 children were enrolled in this study, and they completed 12 weeks of atomoxetine treatment. The QCD results indicated that the atomoxetine treatment could significantly alleviate behavioral difficulties in primary children with ADHD, especially in the morning prior to school (p < 0.001, r = 0.66) and in the evening (p < 0.001, r = 0.73). A statically significant decrease in weight SDS (p < 0.05) was noted during treatment, but the effect size was slight (r = 0.09). The atomoxetine treatment had no significant impact on height SDS, BMI SDS, and serum growth parameters, such as the levels of IGF-1, IGFBP-3, and thyroid function. The SNAP-IV results showed a significant improvement in the core symptoms of ADHD, while the CPRS results indicated a significant improvement in controlling ADHD symptoms across two different domains, learning problems (r = 0.81) and hyperactivity (r = 0.86). No severe adverse reactions were observed in the course of treatment, and the most common adverse reactions were gastrointestinal symptoms. (4) Conclusions: Atomoxetine is an effective and safe treatment for primary school children with ADHD. In China, it may be an excellent choice to alleviate parenting stress and improve the condition of primary school children with ADHD. Moreover, our study indicated that the serum levels of IGF-1 and IGFBP-3 were within the normal range in newly diagnosed ADHD children, and atomoxetine will not affect the serum concentration of growth parameters, such as IGF-1, IGFBP-3, and thyroid function, in the short term. However, the treatment may reduce appetite, resulting in a reduction in the Children’s weight for a short period. Further observational studies to monitor the long-term effects of atomoxetine on primary school children are recommended.

Effects of Atomoxetine Hydrochloride on Regulation of Lifespan in Drosophila Model

Nootropics (smart drugs) are used by students to enhance cognitive performance which have been reported times in recent years. However, some of the nootropics are central nervous system stimulants which are very likely to lead to addiction or complications such as vomiting and dizziness. Are there nootropics that can improve learning behavior while having potential positive effect on health? Here, we reported that Atomoxetine (ATX) has sex-specific effect on prolonging the life span of female Drosophila melanogaster. Further study indicated that ATX enhanced female resistance to heat stress and their vertical climbing ability, but it did decrease the number of eggs laid. ATX increased food-intake and sleep time both of females and males, and significantly reduced the 24h spontaneous activity of females and males. Our results present the sex dimorphic effect of ATX on life span regulation in Drosophila, and support further research on the beneficial role of ATX and the mechanisms in other animal models.

Mitochondrial DNA copy number may be associated with attention deficit/hyperactivity disorder severity in treatment: a one-year follow-up study

OBJECTIVE

Studies on etiopathogenesis of attention deficit/hyperactivity disorder (ADHD) are increasingly focussing on mitochondrial dysfunction. Children diagnosed with ADHD who had significantly higher mitochondrial DNA (mtDNA) copy numbers than healthy children in our first study were re-examined in 1-year follow-up to investigate effects of severity and treatment of ADHD on mtDNA.

METHODS

Twenty-eight patients who participated in previous study were included in this follow-up study. Patients were equally divided into two groups according to whether they had been receiving treatment. Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version, and Conners Parent Rating Scale (CPRS) were used. Polymerase chain reaction was performed.

RESULTS

Means of the first and second mtDNA copy were similar in all patients. mtDNA copy numbers did not change between two measurements in treated and non-treated groups. There was a correlation between CPRS ADHD index and inattention scores and mtDNA copy number in treated group. mtDNA copy number did not change in patients with ADHD over a period of 1 year regardless of treatment.

CONCLUSIONS

There may be a relationship between decreased ADHD severity with treatment and positive effects of mitochondrial functions. Mitochondrial dysfunction may play a role in pathophysiology of ADHD.KEY POINTSThis was the first study to follow up ADHD patients in order to investigate mitochondrial dysfunction by measuring mtDNA copy numbers 1 year after the initial measurements.mtDNA copy number, one of the best markers of mitochondrial dysfunction, did not change in ADHD patients over a period of 1 year regardless of treatment.Mitochondrial dysfunction may play a role in the pathophysiology of ADHD, where it may be involved with or without treatment.In the treated group, there was an association between decreased ADHD severity and reduced mtDNA copy numbers.There may be a relationship between decreased ADHD severity with treatment and the positive effects of mitochondrial functions.

Alternations in nuclear factor kappa beta activity (NF-kB) in the rat brain due to long-term use of atomoxetine for treating ADHD: In vivo and in silico studies

Attention Deficit Hyperactivity Disorder (ADHD) is the most common psychiatric disorder reported particularly in children. Long-term use of antipsychotic drugs used in the treatment of ADHD has been shown to exert toxic effects on the brain. However, not enough research has been carried out on the neurotoxic effects of these drugs on the brain tissue. Atomoxetine (ATX) is the most widely used antipsychotic drug that has gained approval for ADHD treatment. The present study aims to determine the damage induced by long-term use of three different doses of ATX in the brain tissue of experimental rats. 24 rats were divided into Control group (0.5 mL saline), Group 2 (0.5 mg/mL ATX), Group 3 (1.0 mg/mL ATX), and Group 4 (2.0 mg/mL ATX), each group having 6 members. Their brain tissues were taken for stereological, histological, and nuclear factor kappa-B (NF-kB) protein expression analysis. ATX was determined to have caused a few alterations in the brain tissue, such as disruption in the endothelial epithelium of capillaries, a couple of large astrocyte nuclei, and mitotic astrocytes. Moreover, a significant difference was observed in Group 4 compared to Control Group in terms of astrocyte counts in the brain sections. As for Groups 3 and 4, there were differences in terms of oligodendrocyte counts in the incisions cultivated from the brain tissues of the animals. On the other hand, NF-kB positive astrocytes of Groups 3 and 4 differed significantly from those of Control and Group 2. The results of molecular dockings of the present study are in line with the in-vivo results. Therefore, it was concluded that the higher the dose of ATX was, the more damage the brain tissue sustained.

Role of Oxidative Stress and Neuroinflammation in Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder of childhood. Although abnormalities in several brain regions and disturbances of the catecholaminergic pathway have been demonstrated, the pathophysiology of ADHD is not completely understood, but as a multifactorial disorder, has been associated with an increase in oxidative stress and neuroinflammation. This review presents an overview of factors that increase oxidative stress and neuroinflammation. The imbalance between oxidants and antioxidants and also the treatment with medications are two factors that can increase oxidative damage, whereas the comorbidity between ADHD and inflammatory disorders, altered immune response, genetic and environmental associations, and polymorphisms in inflammatory-related genes can increase neuroinflammation. Evidence of an association with these factors has become valuable for research on ADHD. Such evidence opens up new intervention routes for the use of natural products as antioxidants that could have potential as a treatment against oxidative stress and neuroinflammation in ADHD.

Evaluation of the efficacy of drug treatment based on measurement of the oxidative stress, using reactive oxygen metabolites and biological antioxidant potential, in children with autism spectrum disorder and attention deficit hyperactivity disorder

Background

Autism spectrum disorder (ASD) is a neurodevelopmental disorder, mainly characterized by impairment of social communication and restricted interests. ASD is frequently accompanied by attention deficit hyperactivity disorder (ADHD), which is characterized by carelessness, hyperactivity and impulsivity (ASD/ADHD). It has been suggested that ASD and ADHD are associated with oxidative stress, that is, that patients with ASD/ADHD are in a state of increased oxidative stress. There are currenr tly no objective or biological test criteria for evaluating the efficacy of drug therapy in these patients. The purpose of this study was to evaluate whether oxidative stress markers [serum reactive oxygen metabolites (d-ROMs) levels and biological antioxidant potential (BAP)] can be used as objective indicators for evaluating the efficacy of drug treatment in ASD/ADHD patients.

Methods

The subjects of this study subjects were 50 Japanese patients with ASD/ADHD aged 4 to 14 years old. Serum samples were obtained from the patients to measure the serum levels of d-ROMs and the serum BAP. The study subjects were divided into two age groups: preschool children (4 to 6 years old) and school-age children (7 to 14 years old), and the serum levels of d-ROMs, serum BAP, serum BAP/d-ROMs ratio (hereinafter, the prefix serum will be dropped), and scores on the Parent-interview ASD Rating Scales-Text Revision (PARS-TR) and ADHD Rating Scale (ADHD-RS) were determined before and after drug therapy and compared between the two groups. In addition, changes in the d-ROMs, BAP and BAP/d-ROMs ratio and changes in the scores on the PARS-TR and ADHD-RS after treatment were also analyzed.

Results

Significant decrease of the d-ROMs, BAP, and scores on the PARS-TR and ADHD-RS, with a significant increase of the BAP/d-ROMs ratio, was observed after treatment. In addition, a significant correlation was observed between the changes in the d-ROMs and changes in the scores on the PARS-TR and ADHD-RS after treatment in the school-age ASD/ADHD children.

Conclusion

Our results suggest the possibility that the serum level of d-ROMs may be useful as an objective assessment marker to supplement the subjective assessment of the effects of drug treatment in school-age children with ASD/ADHD.

Antioxidants as a Potential Target against Inflammation and Oxidative Stress in Attention-Deficit/Hyperactivity Disorder

Psychostimulants and non-psychostimulants are the medications prescribed for the treatment of attention-deficit/hyperactivity disorder (ADHD). However, several adverse results have been linked with an increased risk of substance use and side effects. The pathophysiology of ADHD is not completely known, although it has been associated with an increase in inflammation and oxidative stress. This review presents an overview of findings following antioxidant treatment for ADHD and describes the potential amelioration of inflammation and oxidative stress using antioxidants that might have a future as multi-target adjuvant therapy in ADHD. The use of antioxidants against inflammation and oxidative conditions is an emerging field in the management of several neurodegenerative and neuropsychiatric disorders. Thus, antioxidants could be promising as an adjuvant ADHD therapy.