Quantification of ADHD medication in biological fluids of pregnant and breastfeeding women with liquid chromatography: a comprehensive review.

Attention Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder that has long been considered a concern only in the pediatric population. However, symptoms often sustain into adulthood and may require medication. For women with ADHD, this also means dealing with the disorder during the reproductive period. Medication safety during pregnancy and breastfeeding is a critical concern, and the potential transfer of ADHD medication to infants remains a topic of scientific interest. The quantification of ADHD medications in both maternal blood and breast milk are vital for understanding their pharmacokinetics and potential exposure risks for (nursing) infants. This review aims (1) to compile and critically assess existing research on the transfer of ADHD medications into breast milk and the potential implications for nursing infants and (2) to provide a comprehensive overview and discussion of the literature regarding the quantification of methylphenidate, amphetamine, atomoxetine, viloxazine, guanfacine, clonidine and bupropion in the blood, urine, oral fluid, and breast milk with liquid chromatography. A literature search was conducted using PubMed, Scopus, and Web of Science, to identify relevant articles published from January 2014 up to December 2023. We illustrate the lack of methods to simultaneously monitor multiple ADHD medications as well as the lack of developed methods for breast milk. Finally, we highlight the need for continued research to refine our understanding of medication transfer into breast milk and potential risks, and to develop clinical guidelines to support mothers with ADHD in making informed choices regarding medication use during pregnancy and lactation.

Attention-Deficit/Hyperactivity Disorder in Adults.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder involving functionally disruptive inattentive and/or hyperactive/impulsive behaviors, such as being easily distracted, regularly failing to follow through on tasks, being restless, or often interrupting others. ADHD diagnosed in childhood often persists into adulthood, with 14.6% of U.S. adults meeting the Diagnostic and Statistical Manual of Mental Disorders, 5th ed., criteria for ADHD. When evaluating for adult ADHD, other mental disorders should be included in the differential diagnosis due to the substantial overlap of symptoms and ADHD concurrence with anxiety/stress, mood, personality, impulse control, and substance use disorders. An ADHD diagnosis requires a comprehensive clinical history and evaluation, patient symptom and function assessment (e.g., Adult ADHD Self-Report Scale, Conners Adult ADHD Rating Scales), and gathering of collateral information. Clinical guidelines recommend a subset of amphetamine and methylphenidate stimulants as first-line pharmacotherapy, which may be more effective when combined with psychotherapy. For adults unable to take stimulants or with concurrent anxiety/depression, options include atomoxetine, viloxazine, and bupropion. To monitor for patient misuse or diversion of stimulants, physicians should consider employing controlled substance agreements and prescription drug monitoring programs.

The effect of a single dose of methylphenidate on attention in children and adolescents with ADHD and comorbid Oppositional Defiant Disorder.

The co-occurrence Oppositional Defiant Disorder (ODD) in children and adolescents with Attention Deficit Hyperactivity Disorder (ADHD) has been associated to difficulties in regulating adverse states, elevated functional impairment, deficits in Executive Functions and high risk for psychopathology. Recent studies have shown that ODD is a negative predictor of a positive response to methylphenidate (MPH) treatment for ADHD symptoms in children and adolescents and that patients with a diagnosis of comorbid ADHD and ODD are less likely to respond favorably to pharmacological treatment with MPH. We conducted a naturalistic study to understand the clinical characteristics of drug-naïve children and adolescents with ADHD that influence the response to MPH by measuring the effect on attention. Specifically, we investigated whether a single dose of MPH differently affects the performance of 53 children and adolescents with ADHD with or without ODD comorbidity. In addition, participant characteristics such as symptom severity, functional impairment, and associated behavioral and emotional symptoms at baseline were examined to better understand what aspects affect the response to MPH. We found that a single dose of MPH improved the attention of children and adolescents with ADHD without ODD more than those with comorbid ADHD and ODD, resulting in reduced reaction times. Our findings indicated that children and adolescents with comorbid ADHD and ODD and those with ADHD alone did not exhibit differences in measures of attention prior to taking MPH, nor in demographic variables (age, intelligence quotient, gender), clinical characteristics related to symptom severity, and adaptive behaviors. However, we observed differences between the two groups in certain behavioral aspects, including the Dysregulation Profile and disruptive behaviors. Assessing symptoms in combination with the presence of ADHD can be beneficial in determining which individuals would derive the greatest benefits from treatment.

Dopamine reuptake and inhibitory mechanisms in human dopamine transporter.

The dopamine transporter has a crucial role in regulation of dopaminergic neurotransmission by uptake of dopamine into neurons and contributes to the abuse potential of psychomotor stimulants1-3. Despite decades of study, the structure, substrate binding, conformational transitions and drug-binding poses of human dopamine transporter remain unknown. Here we report structures of the human dopamine transporter in its apo state, and in complex with the substrate dopamine, the attention deficit hyperactivity disorder drug methylphenidate, and the dopamine-uptake inhibitors GBR12909 and benztropine. The dopamine-bound structure in the occluded state precisely illustrates the binding position of dopamine and associated ions. The structures bound to drugs are captured in outward-facing or inward-facing states, illuminating distinct binding modes and conformational transitions during substrate transport. Unlike the outward-facing state, which is stabilized by cocaine, GBR12909 and benztropine stabilize the dopamine transporter in the inward-facing state, revealing previously unseen drug-binding poses and providing insights into how they counteract the effects of cocaine. This study establishes a framework for understanding the functioning of the human dopamine transporter and developing therapeutic interventions for dopamine transporter-related disorders and cocaine addiction.

Differential Impact of Serotonin Signaling Methylphenidate on Young versus Adult: Insights from Behavioral and Dorsal Raphe Nucleus Neuronal Recordings from Freely Behaving Rats.

Methylphenidate (MPD) remains a cornerstone pharmacological intervention for managing ADHD, yet its increasing usage among ordinary youth and adults outside clinical contexts necessitates a thorough investigation into its developmental effects. This study seeks to simultaneously investigate the behavioral and neuronal changes within the dorsal raphe (DR) nucleus, a center of serotonergic neurons in the mammalian brain, before and after the administration of varying doses of acute and chronic MPD in freely behaving young and adult rats implanted with DR recording electrodes. Wireless neuronal and behavioral recording systems were used over 10 consecutive experimental days. Eight groups were examined: saline, 0.6, 2.5, and 10.0 mg/kg MPD for both young and adult rats. Six daily MPD injections were administered on experimental days 1 to 6, followed by a three-day washout period and MPD re-administration on experimental day 10 (ED10). The analysis of neuronal activity recorded from 504 DR neurons (DRNs) in young rats and 356 DRNs in adult rats reveals significant age-dependent differences in acute and chronic MPD responses. This study emphasizes the importance of aligning electrophysiological evaluations with behavioral outcomes following extended MPD exposure, elucidating the critical role of DRNs and serotonin signaling in modulating MPD responses and delineating age-specific variations in young versus adult rat models.

Cerebellar network alterations in adult attention-deficit/hyperactivity disorder.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental condition that often persists into adulthood. Underlying alterations in brain connectivity have been identified but some relevant connections, such as the middle, superior, and inferior cerebellar peduncles (MCP, SCP, and ICP, respectively), have remained largely unexplored; thus, we sought to investigate whether the cerebellar peduncles contribute to ADHD pathophysiology among adults. METHODS: We applied diffusion-weighted spherical deconvolution tractography to dissect the cerebellar peduncles of male adults with ADHD (including those who did or did not respond to methylphenidate, based on at least 30% symptom improvement at 2 months) and controls. We investigated differences in tract metrics between controls and the whole ADHD sample and between controls and treatment-response groups using sensitivity analyses. Finally, we analyzed the association between the tract metrics and cliniconeuropsychological profiles. RESULTS: We included 60 participants with ADHD (including 42 treatment responders and 18 nonresponders) and 20 control participants. In the whole ADHD sample, MCP fractional anisotropy (FA; t 78 = 3.24, p = 0.002) and hindrance modulated orientational anisotropy (HMOA; t 78 = 3.01, p = 0.004) were reduced, and radial diffusivity (RD) in the right ICP was increased (t 78 = -2.84, p = 0.006), compared with controls. Although case-control differences in MCP FA and HMOA, which reflect white-matter microstructural organization, were driven by both treatment response groups, only responders significantly differed from controls in right ICP RD, which relates to myelination (t 60 = 3.14, p = 0.003). Hindrance modulated orientational anisotropy of the MCP was significantly positively associated with hyperactivity measures. LIMITATIONS: This study included only male adults with ADHD. Further research needs to investigate potential sex- and development-related differences. CONCLUSION: These results support the role of the cerebellar networks, especially of the MCP, in adult ADHD pathophysiology and should encourage further investigation. CLINICAL TRIAL REGISTRATION: NCT03709940.

Add-On Bifidobacterium Bifidum Supplement in Children with Attention-Deficit/Hyperactivity Disorder: A 12-Week Randomized Double-Blind Placebo-Controlled Clinical Trial.

We conducted a 12-week randomized double-blind placebo-controlled clinical trial to investigate the potential impact of Bifidobacterium bifidum (Bf-688) supplementation on attention-deficit/hyperactivity disorder (ADHD). Children with ADHD who were already receiving a stable dose of methylphenidate (MPH) treatment were enrolled and were randomly assigned to two groups: one receiving add-on Bf-688 (daily bacterial count of 5 × 109 CFUs) (n = 51) and the other receiving a placebo (n = 51). All participants underwent assessments using Conners' Continuous Performance Test (CPT) and Conners' Continuous Auditory Test of Attention (CATA). Additionally, fecal samples were collected at the beginning of the trial (week 0) and at the endpoint (week 12). Remarkably, the group receiving Bf-688 supplementation, but not the placebo group, exhibited significant improvements in omission errors in CPT as well as Hit reaction time in both CPT and CATA. Gut microbiome analysis revealed a significant increase in the Firmicutes to Bacteroidetes ratio (F/B ratio) only in the Bf-688 group. Furthermore, we identified significant negative correlations between N-Glycan biosynthesis and Hit reaction time in both CPT and CATA. Our results demonstrate that the probiotic Bf-688 supplement can enhance neuropsychological performance in children with ADHD, possibly by altering the composition of the gut microbiota, ultimately leading to reduced N-Glycan biosynthesis.

Psilocybin desynchronizes the human brain.

A single dose of psilocybin, a psychedelic that acutely causes distortions of space-time perception and ego dissolution, produces rapid and persistent therapeutic effects in human clinical trials1-4. In animal models, psilocybin induces neuroplasticity in cortex and hippocampus5-8. It remains unclear how human brain network changes relate to subjective and lasting effects of psychedelics. Here we tracked individual-specific brain changes with longitudinal precision functional mapping (roughly 18 magnetic resonance imaging visits per participant). Healthy adults were tracked before, during and for 3 weeks after high-dose psilocybin (25 mg) and methylphenidate (40 mg), and brought back for an additional psilocybin dose 6-12 months later. Psilocybin massively disrupted functional connectivity (FC) in cortex and subcortex, acutely causing more than threefold greater change than methylphenidate. These FC changes were driven by brain desynchronization across spatial scales (areal, global), which dissolved network distinctions by reducing correlations within and anticorrelations between networks. Psilocybin-driven FC changes were strongest in the default mode network, which is connected to the anterior hippocampus and is thought to create our sense of space, time and self. Individual differences in FC changes were strongly linked to the subjective psychedelic experience. Performing a perceptual task reduced psilocybin-driven FC changes. Psilocybin caused persistent decrease in FC between the anterior hippocampus and default mode network, lasting for weeks. Persistent reduction of hippocampal-default mode network connectivity may represent a neuroanatomical and mechanistic correlate of the proplasticity and therapeutic effects of psychedelics.

Assessment of centanafadine in adults with ADHD: a matching adjusted indirect comparison versus methylphenidate hydrochloride extended release (Concerta).

OBJECTIVE: To compare safety and efficacy of centanafadine versus methylphenidate hydrochloride extended release (ER; Concerta) in adults with ADHD. METHODS: Without head-to-head trials, anchored matching-adjusted indirect comparisons (MAIC) of adverse event rates reported across trials and mean change from baseline in Adult ADHD Investigator Symptom Rating Scale (AISRS) score between centanafadine and methylphenidate hydrochloride ER were conducted. Pooled patient-level data from two centanafadine trials (NCT03605680/NCT03605836) and aggregate data from one published methylphenidate hydrochloride ER trial (NCT00937040) were used. Characteristics of individual patients from the centanafadine trials were matched to aggregate baseline characteristics from the methylphenidate hydrochloride ER trial using propensity score weighting. A sensitivity analysis assessed the robustness of the results to the capping of extreme weights (i.e. >99th percentile). RESULTS: Compared with methylphenidate hydrochloride ER, centanafadine was associated with significantly lower risk of dry mouth (risk difference [RD] in percentage points: -11.95), initial insomnia (-11.10), decreased appetite (-8.05), anxiety (-5.39), palpitations (-5.25), and feeling jittery (-4.73) though a significantly smaller reduction in AISRS score (4.16-point). In the sensitivity analysis, the safety results were consistent with the primary analysis but there was no significant difference in efficacy between centanafadine and methylphenidate hydrochloride ER. CONCLUSION: In this MAIC, centanafadine had better safety and possibly lower efficacy than methylphenidate hydrochloride ER. While safety results were robust across analyses, there was no efficacy difference between centanafadine and methylphenidate hydrochloride ER in the sensitivity analysis. Considering its favorable safety profile, centanafadine may be preferred among patients for whom treatment-related adverse events are a concern.

Toxicity of New Psychoactive Substance (NPS): Threo-4-methylmethylphenidate (4-Mmph) - Prediction of toxicity using in silico methods.

This study represents the first application of in silico methods to evaluate the toxicity of 4-methylphenidate (4-Mmph), a new psychoactive substance (NPS). Using advanced in silico toxicology tools, it was feasible to anticipate key aspects of 4-Mmph's toxicological profile, including acute toxicity (LD50), genotoxicity, cardiotoxicity, and possible endocrine disruption. The findings indicate significant acute toxicity with variability among species, a high potential for adverse effects in the gastrointestinal system and lungs, a low genotoxic potential, a significant likelihood of skin irritation, and a notable cardiotoxicity risk associated with hERG channel inhibition. Evaluation of endocrine disruption revealed a low likelihood that 4-Mmph interacts with the estrogen receptor alpha (ER-α), indicating minimal estrogenic activity. These insights, derived from in silico studies, play a crucial role in improving the comprehension of 4-Mmph in forensic and clinical toxicology. These initial toxicological inquiries establish the foundation for future investigations and help formulate risk assessment and management strategies regarding the use and abuse of NPS. This article is part of a larger project funded by the Polish Ministry of Education and Science, titled "Toxicovigilance, Poisoning Prevention, and First Aid in Poisoning with Xenobiotics of Current Clinical Importance in Poland" (Grant Number SKN/SP/570184/2023).

Effectiveness of pharmacological interventions for managing ADHD symptoms in individuals with autism spectrum disorder: A systematic review and meta-analysis.

OBJECTIVES: This systematic review sought to provide evidence for the effectiveness of common pharmacological interventions used for treating attention deficit hyperactivity disorder (ADHD) symptoms in the autism spectrum disorder (ASD) population, considering studies attempting to find safe and effective drugs. METHODS: We searched for randomized controlled trials describing the effectiveness and/or safety profile of pharmacological interventions for treating ASD and ADHD or ASD with ADHD symptoms using three bibliographic databases: PubMed, Cochrane Library, and Embase. We have chosen ADHD symptoms measured by any clinical scale as the primary outcome. As additional outcomes, we have used other symptoms of aberrant behavior measured by the aberrant behavior checklist, satisfaction with treatment, and peer satisfaction. RESULTS: Twenty-two publications met the inclusion criteria for the systematic review and eight for the meta-analysis. In our investigation, we found a few articles using clonidine, modafinil, and bupropion as interventions when compared to methylphenidate (MPH). Our meta-analysis showed that MPH had positive changes compared to placebo in symptoms such as hyperactivity, irritability, or inattention. However, no effect was found in stereotyped symptoms, and our data's quantitative analysis revealed a large effect of MPH-induced adverse effects on the dropout rate. On the other hand, atomoxetine initiation had positive effects when compared to placebo on symptoms of hyperactivity and inattention. We have found no effect of atomoxetine on stereotypes or irritability. Furthermore, atomoxetine did not influence side effects that caused dropouts from studies. CONCLUSION: Our results indicated that atomoxetine has a modest effect on hyperactivity and inattention symptoms, with a relatively benign profile of side effects. MPH appears to be effective in handling hyperactivity, inattention, and irritability symptoms. However, our results on atomoxetine revealed increased dropouts due to adverse effects when compared to MPH or placebo. Evidence for other substances such as guanfacine, clonidine, bupropion, or modafinil is either preliminary or nonexistent.

Use of methylphenidate and reporting of valvular heart disease: Global pharmacovigilance analysis in children and adults.

INTRODUCTION: Methylphenidate (MPH) is a common treatment of attention-deficit/hyperactivity disorder (ADHD). Concern has been raised regarding its cardiovascular safety, partly in relation with its micromolar affinity for the 5-HT2B receptor, whose activation may result in valvular heart disease (VHD). METHODS: To explore the association between the use of MPH and VHD reporting, we performed a disproportionality analysis within the WHO global safety database (VigiBase) using data, since inception until March 6th 2024, from: (i) the full database and (ii) different age groups (children/adolescents 6-17 years; adults 18-64 years). To avoid competition bias, safety reports with amphetamine-like appetite suppressants were excluded. Disproportionality was expressed using reporting odds-ratio (ROR) and its 95% confidence interval (CI). RESULTS: Of 29 129 spontaneous reports with MPH, 23 VHD cases (7.9 per 10 000 reports) were identified, including 13 adults and 10 children. Most cases concerned injury on the mitral valve. A disproportionate reporting was observed overall (ROR 1.6, 95% CI 1.1-2.4). Analysis according to age group found that disproportionality in VHD reporting was found in adults only (ROR 2.7, 95% CI 1.6-4.7) but not in children/adolescents (ROR 1.7, 95% CI 0.9-3.2). Furthermore, amongst MPH users only, VHD reporting was higher in adults compared to children (ROR 2.7, 95% CI 1.2-6.3). CONCLUSION: VHD reporting appears rare with MPH compared to other adverse events and is increased in adults only. Our findings support a potential safety signal of VHD in adults exposed to MPH. A risk in that population cannot be excluded and requires further assessment.

Association between Early Guanfacine Discontinuation and Somnolence for Attention-Deficit/Hyperactivity Disorder.

Guanfacine, used as a medication for attention-deficit/hyperactivity disorder (ADHD), leads to a high incidence of somnolence, in contrast to methylphenidate, which leads to a high incidence of insomnia. The impact of somnolence on continuing guanfacine treatment is unclear. Therefore, we investigated the reasons for discontinuing guanfacine and analyzed the factors associated with discontinuation caused by somnolence. We surveyed 96 patients under guanfacine from July 2017 to December 2021 at the Saga University Hospital. Patients who discontinued guanfacine by the end date of our study were divided into a median early and late group. We compared the reasons for discontinuation in both groups. Of all patients, 47 continued and 49 discontinued guanfacine. A higher percentage of patients discontinued guanfacine caused by somnolence for ≤70 d than for >70 d of treatment (44.0 vs. 8.3%; p = 0.008). When stratified by the concomitant use of other ADHD drugs, somnolence resulted in a higher discontinuation rate for ≤70 d than for >70 d of treatment without concomitant use (55.0 vs. 7.1%; p = 0.009). Nonetheless, concomitant use resulted in no difference. In conclusion, somnolence affects the early discontinuation of guanfacine as an ADHD drug. The combination of methylphenidate or atomoxetine may decrease withdrawal caused by somnolence.

Graph analysis uncovers an opposing impact of methylphenidate on connectivity patterns within default mode network sub-divisions.

BACKGROUND: The Default Mode Network (DMN) is a central neural network, with recent evidence indicating that it is composed of functionally distinct sub-networks. Methylphenidate (MPH) administration has been shown before to modulate impulsive behavior, though it is not yet clear whether these effects relate to MPH-induced changes in DMN connectivity. To address this gap, we assessed the impact of MPH administration on functional connectivity patterns within and between distinct DMN sub-networks and tested putative relations to variability in sub-scales of impulsivity. METHODS: Fifty-five right-handed healthy adults underwent two resting-state functional MRI (rs-fMRI) scans, following acute administration of either MPH (20 mg) or placebo, via a randomized double-blind placebo-controlled design. Graph modularity analysis was implemented to fractionate the DMN into distinct sub-networks based on the impact of MPH (vs. placebo) on DMN connectivity patterns with other neural networks. RESULTS: MPH administration led to an overall decreased DMN connectivity, particularly with the auditory, cinguloopercular, and somatomotor networks, and increased connectivity with the parietomedial network. Graph analysis revealed that the DMN could be fractionated into two distinct sub-networks, with one exhibiting MPH-induced increased connectivity and the other decreased connectivity. Decreased connectivity of the DMN sub-network with the cinguloopercular network following MPH administration was associated with elevated impulsivity and non-planning impulsiveness. CONCLUSION: Current findings highlight the intricate effects of MPH administration on DMN rs-fMRI connectivity, uncovering its opposing impact on distinct DMN sub-divisions. MPH-induced dynamics in DMN connectivity patterns with other neural networks may account for some of the effects of MPH administration on impulsive behavior.

Complex ADHD Challenging Case: Managing Co-Occurring Attention-Deficit Hyperactivity Disorder and Congenital Heart Disease with a Limited Medication Formulary: A Case from Mexico.

CASE: DL is an 8-year-old Mexican boy with a posterior atrial septal defect and partial anomalous pulmonary venous return of the right lower pulmonary vein with resultant right heart dilation with normal right ventricular systolic and diastolic function and no arrhythmias. Surgical repair was deferred, and DL's condition was being medically managed with furosemide 0.5 mg/kg BID and spironolactone 0.5 mg/kg BID.DL presents for developmental assessment due to poor performance in school following a lifting of COVID-19 pandemic restrictions and return to in-person classes. He has been attending full-time classes for 3 months without improvements in math, reading, and writing skills. Current attentional concerns at school include an inability to complete tasks without getting distracted by minimal stimuli and highly impulsive behavior.At the first assessment, DL was performing below grade expectations (e.g., reading by syllable without text comprehension, demonstrating preoperational addition and subtraction skills, inability to take dictation)-all of which was viewed as negatively impacted by attentional deficits. DL met DSM-5 criteria for ADHD, predominantly inattentive type. He was started on 10-mg immediate-release methylphenidate PO at 8 am with breakfast and a second dose of 10-mg immediate-release methylphenidate PO 4 hours after the first dose.After a month, at the first follow-up consultation, improvement in attention span, impulsivity, and school performance were observed, including reading skills and math proficiency. However, DL's mother raised concerns about circumoral cyanosis and acrocyanosis in the fingers of both hands after playing outside. These signs were not previously observed. During physical examination at the same visit, heart rate, blood pressure, and oximetry were within baseline ranges and his cardiac examination was unchanged. DL's dosage of methylphenidate was lowered to 10-mg immediate-release methylphenidate PO QD in the mornings with breakfast (8 am).DL did not return to clinic for another 2 months, having discontinued the medication after 2 months of treatment given financial limitations. His mother reported that DL's exertional circumoral cyanosis and acrocyanosis resolved while he was off medication. However, she observed an increase in inattentive symptoms and impulsivity and decline in his academic skills. She asked if our team was able continue the treatment despite the drug side effects, since she believed the benefits outweighed the disadvantages.Given these concerns, the team requested an updated cardiology assessment. The Cardiologist recommended discontinuation of methylphenidate and recommended follow-up with cardiothoracic surgery for reassessment of the surgical timeline.Given the limited treatment options in Mexico, what would you do next as the treating developmental-behavioral clinician…?

Effects of 2 months of methylphenidate on energy expenditure in individuals with obesity: A randomized, double-blind, placebo-controlled pilot study.

Methylphenidate (MPH) has been previously shown to increase resting energy expenditure (REE) in individuals of normal weight; however, the effects on individuals living with obesity are currently unknown. Ten individuals living with obesity were randomly assigned to undergo 60 days of MPH administration with a daily dose of 0.5 mg/kg body weight or a placebo control. REE was measured before and after the 60-day intervention. There was a trend toward significance for group × time interaction on REE (p = 0.082) with a large effect size (η2 = 0.331), with MPH administration increasing REE compared to a decrease in placebo control. Preliminary findings from this pilot study show that MPH has the potential to counter the adaptive thermogenic process commonly seen in weight loss. This is a unique finding among pharmacotherapies, as no approved obesity drugs measurably impact REE.

Effects of methylphenidate on mitochondrial dynamics and bioenergetics in the prefrontal cortex of juvenile rats are sex-dependent.

Methylphenidate (MPH) is a central nervous system stimulant drug and a first order prescription in the treatment of Attention Deficit Hyperactivity Disorder (ADHD). Although MPH biochemistry in neurodevelopment is not completely understood, studies showed it alters energy metabolism in rat brains. ADHD prevalence during neurodevelopment is related to males and the investigation has been mainly done in these subjects, therefore, little is known about MPH action in females and, consequently, about sexual dimorphism. In the present study we evaluated markers of mitochondrial dynamics (DRP1 and MFN2, fission and fusion, respectively), biogenesis (mtTFA) and bioenergetics (respiratory chain complexes) in prefrontal cortex of male and female juvenile rats submitted to exposure to MPH to better understand MPH effect during postnatal neurodevelopment. ATP and oxidative stress levels were also evaluated. Wistar rats received intraperitoneal injection of MPH (2.0 mg/kg) or control (saline), once a day, from 15th to 45th day of age. Results showed that MPH increased DRP1 and decreased MFN2, as well as increased mtTFA in prefrontal cortex of male rats. In female, MPH decreased NRF1 and increased Parkin, which are mitochondrial regulatory proteins. Respiratory chain complexes (complex I, SDH, complexes III and IV), ATP production and oxidative stress parameters were altered and shown to be sex-dependent. Taken together, results suggest that chronic MPH exposure at an early age in healthy animals changes mitochondrial dynamics, biogenesis and bioenergetics differently depending on the sex of the subjects.