Chronic administration of caffeine, modafinil, AVL-3288 and CX516 induces time-dependent complex effects on cognition and mood in an animal model of sleep deprivation.

OBJECTIVE: Caffeine and modafinil are used to reverse effects of sleep deprivation. Nicotinic alpha-7 receptor and AMPA receptor positive allosteric modulators (PAM) are also potential substances in this context. Our objective is to evaluate the effects of caffeine, modafinil, AVL-3288 (nicotinic alpha-7 PAM) and CX516 (AMPA receptor PAM) on cognition and mood in a model of sleep deprivation. METHOD: Modified multiple platform model is used to sleep-deprive mice for 24 days, for 8 h/day. Vehicle, Modafinil (40 mg/kg), Caffeine (5 mg/kg), CX516 (10 mg/kg), and AVL3288 (1 mg/kg) were administered intraperitoneally daily. A cognitive test battery was applied every six days for four times. The battery that included elevated plus maze, novel object recognition, and sucrose preference tests was administered on consecutive days. RESULTS: Sleep deprivation decreased novel object recognition skill, but no significant difference was found in anxiety and depressive mood. Caffeine administration decreased anxiety-like behavior in short term, but this effect disappeared in chronic administration. Caffeine administration increased memory performance in chronic period. AVL group showed better memory performance in short term, but this effect disappeared in the rest of experiment. Although, in the modafinil group, no significant change in mood and memory was observed, anhedonia was observed in the chronic period in vehicle, caffeine and modafinil groups, but not in AVL-3288 and CX-516 groups. CONCLUSION: Caffeine has anxiolytic effect in acute administration. The improvement of memory in chronic period may be associated with the neuroprotective effects of caffeine. AVL-3288 had a short-term positive effect on memory, but tolerance to these effects developed over time. Furthermore, no anhedonia was observed in AVL-3288 and CX516 groups in contrast to vehicle, caffeine and modafinil groups. This indicates that AVL-3288 and CX516 may show protective effect against depression.

Escalating caffeine dose-dependently increases alcohol consumption in adult male, but not female, C57BL/6J mice.

Although previous research has illustrated the effects of the consumption of alcohol and caffeine individually, less research has focused on the popular combination of the two drugs. The increase in alcohol consumption when combined with caffeine has led to the idea that the stimulant effects of caffeine may mask the depressant effects of alcohol, and this may contribute to increased binge drinking as the individual feels more awake and stimulated. Preclinical research has shown various effects of combined alcohol and caffeine where several studies show decreased alcohol consumption and others show increased alcohol consumption and even binge-like drinking. Results from a previous study in our lab indicate that intermittent access (IA) to steady levels of low (0.015 %) but not moderate (0.03 %) caffeine increased alcohol consumption in male C57BL/6J mice. The current studies further investigated the sex and dose differences in adult mice receiving varying concentrations of caffeine on combined alcohol intake. In Experiment 1, adult mice (n = 50, 25 males and 25 females) had IA to one of the following experimental bottles throughout the 4 week period: water, alcohol (10 % v/v), caffeine (0.015 % w/v), or 10 % alcohol +0.015 % caffeine. In Experiment 2, adult mice (n = 70, 35 males and 35 females) were given IA to one of the following experimental bottles: water, alcohol (10 % v/v; steady, maintained throughout the 4 weeks), caffeine (increasing 0.01 % to 0.015 % to 0.02 % to 0.03 % weekly), or 10 % alcohol+increasing caffeine (at the previously mentioned concentrations). When both caffeine and alcohol concentrations remained steady throughout the 4 weeks, there was no change in alcohol consumption. Chronic exposure to IA caffeine led to increased locomotor activity and decreased freezing episodes when tested in the open field test approximately 6 h after removal of the bottles. In Experiment 2, caffeine dose-dependently increased alcohol co-consumption in male mice whereas female mice consumed less alcohol when it was presented in conjunction with caffeine. The results in males are in line with clinical literature suggesting that the combination of alcohol and caffeine may lead to increased stimulation and alcohol drinking. Additionally, these studies provide evidence that the escalation of caffeine is crucial when investigating alcohol and caffeine co-consumption using the IA paradigm.

Predictors for poor daily weight gain in preterm neonates exposed to different dose regimens of caffeine in ICU- a retrospective cohort study.

BACKGROUND: With a wide therapeutic index, efficacy, ease of use, and other neuroprotective and respiratory benefits, caffeine citrate(CC) is currently the drug of choice for preterm neonates (PTNs). Caffeine-induced excessive energy expenditure, diuresis, natriuresis, and other CC-associated potential side-effects (CC-APSEs) result in lower daily-weight gain (WG) in premature neonates. This study aimed to evaluate the risk factors for daily-WG in neonates exposed to different dose regimens of caffeine in ICU. METHOD: This retrospective cohort study included neonates of ≤ 36weeks gestational age (GA) and received CC-therapy. The same participants were followed for data analysis in two postnatal phases: 15-28 and 29-42 days of life (DOL). Based on daily CC-dose, formed group-I (received; standard-doses = 5 mg/kg/day), group-II (received;>5-7 mg/kg/day), and group-III (received;>7 mg/kg/day). Prenatal and postnatal clinical characteristics, CC-regimen, daily-WG, CC-APSEs, and concomitant risk-factors, including daily-caloric intake, Parenteral-Nutrition duration, steroids, diuretics, and ibuprofen exposure, were analyzed separately for group-II and group-III using group-I as standard. Regression analysis was performed to evaluate the risk factors for daily-WG. RESULTS: Included 314 PTNs. During 15-28 DOL, the mean-daily-WG(MD-WG) was significantly higher in group-I than group-II [19.9 ± 0.70 g/kg/d vs. 17.7 ± 0.52 p = 0.036] and group-III [19.9 ± 0.70 g/kg/d vs. 16.8 ± 0.73 p < 0.001]. During 29-42 DOL the MD-WG of group-I was only significantly higher than group-III [21.7 ± 0.44 g/kg/d vs. 18.3 ± 0.41 g/kg/d p = 0.003] and comparable with group-II. During 15-28 DOL, observed CC-APSEs was significantly higher in group-II and III but during 29-42 DOL it was only significant in group-III. In the adjusted regression analysis for daily-WG during 15-28DOL, with respect to standard-dose, 5-7 mg/kg/day (ß=-1.04; 95%CI:-1.62,-0.93) and > 7-10 mg/kg/day (ß=-1.36; 95%CI:-1.56,-1.02) were associated with a lower daily-WG. However, during 29-42DOL, this association was present only for > 7-10 mg/kg/day (ß=-1.54; 95%CI:-1.66,-1.42). The GA ≤ 27weeks (ß=-1.03 95%CI:-1.24, -0.88) was associated with lower daily-WG only during 15-28DOL. During both periods of therapy, higher cumulative-caffeine dose and presence of culture proven sepsis, tachypnea, hyponatremia, and feeding intolerance were significantly associated with lower daily-WG. Conversely, daily kcal intake was found to be linked with an increase in daily-WG in both periods. CONCLUSION: In this study cohort exposure to higher caffeine daily and cumulative doses is associated with lower postnatal daily-WG in PTNs than standard-daily doses, which may be due to its catabolic effects and CC-APSEs.

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…?

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.

The effects of caffeine ingestion on blood pressure levels in athletic and non-athletic women.

Caffeine is one of the most widely consumed pharmacological substances globally, and is known for its potential ergogenic effects. This study examined the impact of caffeine on the blood pressure in athletic and non-athletic women. Caffeine, a CNS stimulant, enhances athletic performance by boosting stamina, alertness, and cognitive speed. The aim of this study was to assess the impact of caffeine on heart rate and blood pressure in both athletic and non-athletic women, and to inform both groups about its effects. The study was conducted in the Kingdom of Saudi Arabia and involved 30 volunteers aged 18-30 years. Participants were equally divided into three groups: athletes who consumed caffeine, non-athletes who consumed caffeine, and a control group (given a placebo). After caffeine ingestion, there were no significant differences in diastolic blood pressure (DBP), systolic blood pressure (SBP), or heart rate between athletes and non-athletes. These findings suggest that caffeine consumption does not significantly affect blood pressure in either athletic or non-athletic women. However, if it raises blood pressure in both groups, it could pose risks, prompting athletes to consider alternative hydration options such as Gatorade.

La caféine est l'une des substances pharmacologiques les plus largement consommées dans le monde, et est connue pour ses effets ergogéniques potentiels. Cette étude a examiné l'impact de la caféine sur la pression artérielle des femmes athlètes et non athlètes. La caféine, un stimulant du système nerveux central, améliore les performances des athlètes en augmentant l'endurance, la vigilance et la vitesse cognitive. L'objectif de cette étude était d'évaluer l'impact de la caféine sur la fréquence cardiaque et la pression artérielle chez les femmes athlètes et non athlètes, et d'informer les deux groupes de ses effets. L'étude a été menée au Royaume d'Arabie saoudite et a impliqué 30 volontaires âgés de 18 à 30 ans. Les participants ont été répartis également en trois groupes : des athlètes qui ont consommé de la caféine, des non-athlètes qui ont consommé de la caféine, et un groupe témoin (ayant reçu un placebo). Après l'ingestion de caféine, il n'y avait pas de différences significatives dans la pression artérielle diastolique (PAD), la pression artérielle systolique (PAS) ou la fréquence cardiaque entre les athlètes et les non-athlètes. Ces résultats suggèrent que la consommation de caféine n'affecte pas significativement la pression artérielle chez les femmes, qu'elles soient athlètes ou non. Cependant, si elle augmente la pression artérielle dans les deux groupes, cela pourrait présenter des risques, incitant les athlètes à envisager des options d'hydratation alternatives, telles que le Gatorade.

Can Methamphetamine-Induced Cardiotoxicity be Ameliorated by Aerobic Training and Nutrition Bio-shield Superfood Supplementation in Rats After Withdrawal?

The abuse of methamphetamine is a significant threat to cardiovascular health and has detrimental effects on the myocardium. The present study aims to explore potential interventions that can mitigate myocardial pyroptosis in rats following methamphetamine withdrawal. A total of 104 male Wistar rats were randomly assigned to eight groups. The rats underwent a methamphetamine administration protocol, receiving intraperitoneal injections of 10 mg/kg during the 1st week, followed by a weekly dose escalation of 1 mg/kg from the second to the 6th week and two times per day. Concurrently, the rats engaged in 6 weeks of moderate-intensity treadmill aerobic training, lasting 60 min per day, 5 days a week. Simultaneously, the Nutrition bio-shield Superfood (NBS) supplement was administered at a dosage of 25 g/kg daily for 6 weeks. The study assessed the expression levels of Caspase-1, Interleukin-1beta (IL-1ß), and Interleukin-18 (IL-18) genes in myocardial tissue. Data analysis utilized a one-way analysis of variance (p ≤ 0.05). The findings revealed that methamphetamine usage significantly elevated the expression of Caspase-1, IL-1ß, and IL-18 genes (p ≤ 0.05). Conversely, methamphetamine withdrawal led to a notable reduction in the expression of these genes (p ≤ 0.05). Noteworthy reductions in Caspase-1, IL-1ß, and IL-18 expression were observed following aerobic training, supplementation, and the combined approach (p ≤ 0.05). The chronic use of methamphetamine was associated with cardiac tissue damage. This study highlights the potential of aerobic training and NBS Superfood supplementation in mitigating the harmful effects of methamphetamine-induced myocardial pyroptosis. The observed reductions in gene expression levels indicate promising interventions to address the cardiovascular consequences of methamphetamine abuse. The findings of this study suggest that a combination of aerobic exercise and NBS Superfood supplementation can provide a promising approach to mitigate the deleterious effects of methamphetamine on the heart. These findings can be useful for healthcare professionals and policymakers to design effective interventions to prevent and manage the adverse effects of methamphetamine abuse.

Methylphenidate Versus Placebo for Treating Fatigue in Patients With Advanced Cancer: Randomized, Double-Blind, Multicenter, Placebo-Controlled Trial.

PURPOSE: To compare effects and side effects of 6 weeks of individually dose-titrated methylphenidate or placebo on fatigue in palliative care patients with advanced cancer. METHODS: This is a randomized, double-blind, placebo-controlled, multicenter trial. Eligible patients had advanced incurable cancer and fatigue >3/10. Principal exclusions were hypertension; psychiatric, cardiovascular, cerebrovascular, renal, liver, or blood disorders; substance dependency; and epilepsy. Patients were randomly assigned 1:1 methylphenidate or placebo starting at 5 mg twice daily. Dose of methylphenidate/placebo was titrated once per week, over 6 weeks, up to a maximum of 20 mg three times daily. Trial ended at 10 weeks. Primary outcome was the difference in Functional Assessment of Chronic Illness Therapy Fatigue (FACIT-F) scores between groups at 6 ± 2 weeks. Secondary outcomes included adverse effects, quality of life, and mood. RESULTS: One hundred sixty-two patients (73 men; mean, 65.8; standard deviation [SD], 10.3 years) were randomly assigned, and three were excluded from analysis. Seventy-seven were allocated placebo (baseline FACIT-F = 22 [SD, 10]); 82 were allocated methylphenidate (FACIT-F = 20 [SD, 9]). After 6 ± 2 weeks, FACIT-F scores were 1.97 points (95% CI, -0.95 to 4.90; P = .186) higher (better) on methylphenidate than placebo. Across 10 weeks of the study, FACIT-F was nominally higher in the methylphenidate group versus placebo (Diff, 2.20 [95% CI, 0.39 to 4.01]), but this did not reach the minimally clinically important difference (5-points). At 6 weeks, there were no differences between groups in quality-of-life or symptom domains except for depression scores (nominally reduced in the methylphenidate group: Diff, -1.35 [95% CI, -2.41 to -0.30]). There were no differences in mortality or serious adverse events. CONCLUSION: After 6 ± 2 weeks of treatment, methylphenidate was not superior to placebo for treating fatigue in advanced cancer. Methylphenidate was safe and well-tolerated.

The effects of chronic administration of stimulant and non-stimulant medications on executive functions in ADHD: A systematic review and meta-analysis.

Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with executive function deficits that are improved with medications. However, meta-analyses of stimulant effects on cognition have mostly tested single-dose effects, and there is no meta-analysis of non-stimulant effects. This systematic review and meta-analysis tested the clinically more relevant longer-term effects of Methylphenidate (20 studies; minimum 1 week) and Atomoxetine (8 studies; minimum 3 weeks) on reaction time, attention, inhibition, and working memory, searching papers on PubMed, Embase, Ovid MEDLINE, and PsycINFO. The meta-analysis of 18 studies in 1667 subjects showed that methylphenidate was superior to placebo in all cognitive domains with small to medium effect sizes (Hedges g of 0.34-0.59). The meta-analysis of atomoxetine included 7 studies in 829 subjects and showed no effects in working memory, but superior effects in the other domains with medium to large effect sizes (Hedge's g of 0.36-0.64). Meta-regression analysis showed no drug differences on cognitive effects. The meta-analyses show for the first time that chronic Methylphenidate and Atomoxetine have comparable effects of improving executive functions in people with ADHD.

Treatment with dextroamphetamine decreases the reacquisition of cocaine self-administration: Consistency across social contexts.

RATIONALE: A return to cocaine use following abstinence frequently occurs in a social context, and the presence of other individuals using cocaine may contribute to the likelihood of use. Previous studies have reported that chronic d-amphetamine treatment decreases cocaine self-administration in laboratory animals and reduces a return to cocaine use following abstinence in humans. OBJECTIVE: The purpose of this study was to examine the effects of chronic d-amphetamine treatment on the reacquisition of cocaine use in rats self-administering cocaine in different social contexts. METHODS: Male and female rats were implanted with intravenous catheters and trained to self-administer cocaine during daily 6-hr sessions. After 14 days, cocaine self-administration was extinguished by substituting saline for the cocaine stimulus. At this time, rats were randomized to receive chronic treatment with either d-amphetamine or saline. After 9 days of extinction, cocaine was again made available during daily 6-hr sessions. At this time, rats were further randomized into three social conditions: (1) rats continued self-administering cocaine in isolation, (2) rats self-administered cocaine in the presence of a same-sex partner that also self-administered cocaine, or (3) rats self-administered cocaine in the presence of a same-sex partner that did not have access to cocaine. Daily treatment with d-amphetamine or saline continued for the duration of reacquisition testing. RESULTS: Chronic treatment with d-amphetamine decreased cocaine intake during reacquisition, but these effects were not influenced by the social context. No sex differences were observed. CONCLUSION: These data support previous studies reporting that d-amphetamine decreases cocaine intake and demonstrate its efficacy across social contexts.

The effect of methylphenidate on the dopamine and growth hormone response to exercise in children with attention-deficit hyperactivity disorder.

PURPOSE: To assess the growth hormone (GH) and Dopamine (DA) response to exercise in children with attention-deficit hyperactivity disorder (ADHD) with and without methylphenidate (MP). We hypothesized that the GH and DA response to the exercise with MP would be siginicantly lower. METHODS: Twenty children participated in the study (12 males and 8 females, age range 9-13 years). Ten with ADHD and 10 controls. Participants with ADHD performed an exercise test twice, with and without MP while controls performed one exercise test. Blood samples for GH and DA were collected before, at peak, 30 and 60 min after the end of exercise. RESULTS: Compared to controls, children with ADHD with and without MP, had a significantly lower GH (P < .002) and DA (P < .01) responses to exercise. In participants with ADHD, a significantly greater GH response (p < .04) to exercise was found when MP administered to the children before exercise, yet this response was still significantly lower than controls. CONCLUSIONS: GH and DA excretion after an exercise challenge in children with ADHD is impaired. MP slightly attenuates the GH blunted response. This may link ADHD with growth impairment in some children and explain previous findings indicating that the final adult height is usually not compromised in children with ADHD treated with MP. The combined exercise and stimulant treatment therapeutic effects needs to be further explored. TRIAL REGISTRATION NUMBER: NCT00945971.

The Use of Methylphenidate During Inpatient Rehabilitation After Pediatric Traumatic Brain Injury: Population Characteristics and Prescribing Patterns.

OBJECTIVE: To understand how methylphenidate (MPH) is used in youth with traumatic brain injury (TBI) during inpatient pediatric rehabilitation. SETTING: Inpatient pediatric rehabilitation. PARTICIPANTS: In total, 234 children with TBI; 62 of whom received MPH and 172 who did not. Patients were on average 11.6 years of age (range, 2 months to 21 years); 88 of 234 were female; the most common mechanism of injury was motor vehicle collision (49%); median (IQR) acute hospital length of stay (LOS) and inpatient rehabilitation LOS were 16 (10-29) and 23 (14-39), respectively; 51 of 234 were in a disorder of consciousness cognitive state at time of inpatient rehabilitation admission. DESIGN: Multicenter, retrospective medical record review. MAIN MEASURES: Patient demographic data, time to inpatient pediatric rehabilitation admission (TTA), cognitive state, MPH dosing (mg/kg/day). RESULTS: Patients who received MPH were older (P = .011); TTA was significantly longer in patients who received MPH than those who did not (P =.002). The lowest recorded dose range by weight was 0.05 to 0.89 mg/kg/d, representing an 18-fold difference; the weight-based range for the maximum dose was 0.11 to 0.97 mg/kg/d, a 9-fold difference. Patients in lower cognitive states at admission (P = .001) and at discharge (P = .030) were more likely to receive MPH. Five patients had side effects known to be associated with MPH; no serious adverse events were reported. CONCLUSION: This multicenter study indicates that there is variable use of MPH during acute inpatient rehabilitation for children with TBI. Children who receive MPH tend to be older with lower cognitive states. Dosing practices are likely consistent with underdosing. Clinical indications for MPH use during inpatient pediatric rehabilitation should be better defined. The use of MPH, as well as its combination with other medications and treatments, during inpatient rehabilitation needs to be further explored.

Caffeinated Chewing Gum Improves Basketball Shooting Accuracy and Physical Performance Indicators of Trained Basketball Players: A Double-Blind Crossover Trial.

(1) Background: This study investigated the effects of caffeinated chewing gum on the basketball-specific performance of trained basketball players. A double-blind, randomized crossover design was employed. (2) Methods: Fifteen participants (age: 20.9 ± 1.0 years; height: 180.9 ± 5.4 cm; mass: 77.2 ± 7.5 kg; training age: 8.2 ± 0.3 years) were recruited and divided into a caffeine trial (CAF) and placebo trial (PL). The participants in the CAF trial chewed gum containing 3 mg/kg of caffeine for 10 min, while those in the PL trial chewed a placebo gum without caffeine. Following a 15 min rest, all the participants completed basketball-specific performance tests. (3) Results: The free throw accuracy for the CAF trial was significantly higher than that for the PL trial (CAF: 79.0 ± 4.31%; PL: 73.0 ± 9.16%; p = 0.012; Cohen's d = 0.94). Additionally, the CAF trial demonstrated significantly better performance in the 20 m segmented dash (CAF: 2.94 ± 1.12 s; PL: 3.13 ± 0.10 s; p < 0.001; Cohen's d =1.8) and squats (p < 0.05), and exhibited lower fatigue indexes (CAF: 3.6 ± 1.6%; PL: 5.2 ± 1.6%; p = 0.009; Cohen's d =1.0). (4) Conclusions: These findings suggest that chewing gum containing 3 mg/kg of caffeine offers moderate-to-large improvements in key performance aspects relevant to professionally trained basketball players.

Caffeine Expectancy Does Not Influence the Physical Working Capacity at the Fatigue Threshold.

ABSTRACT: Ambrozy, CA, Hawes, NE, Hayden, OL, Sortzi, I, and Malek, MH. Caffeine expectancy does not influence the physical working capacity at the fatigue threshold. J Strength Cond Res 38(6): 1056-1062, 2024-The placebo effect occurs when a desired outcome is experienced due to the belief that a treatment is effective, even in the absence of an active ingredient. One explanation for this effect is based on a person's expectations of a drug or supplement. Although caffeine's effects on sports performance have been studied, little is known about how expectations of caffeine affect neuromuscular fatigue during continuous muscle action. The physical working capacity at the fatigue threshold (PWCFT) can be used to assess neuromuscular fatigue noninvasively using surface electromyography. Thus, the purpose of this study was to investigate whether caffeine expectancy influences PWCFT. We hypothesized that regardless of expectancy, caffeine consumption would delay neuromuscular fatigue. The study involved 8 healthy college-aged men (mean ± SEM: age, 25.6 ± 1.0 years) who visited the laboratory on 4 occasions, each separated by 7 days. The subjects completed 4 experimental conditions, in random order, where they were told that they were consuming caffeine or placebo and either received caffeine or placebo. After consuming the drink, the subjects remained in the laboratory for an hour and then performed an incremental exercise test. The results showed that the condition where subjects were told that they were consuming caffeine and received caffeine had significantly higher mean values for maximal power output (F(3, 21) = 11.75; p < 0.001), PWCFT (F(3, 21) = 12.28; p < 0.001), PWCFT (%maximal power output; F(3, 21) = 8.75; p < 0.001), and heart rate at end exercise (%predicted; F(3, 21) = 3.83; p = 0.025) compared with the 2 conditions where placebo was received. However, no statistically significant mean differences were found from the condition where subjects were told that they were consuming placebo but consuming caffeine. This suggests that a person's expectancy and potential somatic response may serve as a cue for how an ergogenic aid or placebo could affect subsequent performance.

Effects of caffeine on temporal perception in Rattus norvegicus.

We report two studies that tested the effects of caffeine, the world's most widely used psychoactive drug, on temporal perception. We trained Wistar rats using the Bisection Procedure (Experiment 1) or the Stubbs' Procedure (Experiment 2) to discriminate between short and long light stimuli. Once training finished, we administered caffeine orally (0, 9.6, and 96.0 mg/kg for Experiment 1 and 0, 9.6, 19.2, and 38.4 mg/kg for Experiment 2) 15 minutes prior to testing. Relative to the control condition, the 9.6 mg/kg condition (Experiments 1 and 2) and the 19.2 mg/kg condition (Experiment 2) resulted in an increase in proportion of choosing the long response. Meanwhile, overall accuracy was not affected by any condition in both experiments. Taken together, these results are consistent with the notion that caffeine, at some doses, speeds up temporal perception. However, it is not clear why the effect disappears at higher doses.

Timing Matters: Time of Day Impacts the Ergogenic Effects of Caffeine-A Narrative Review.

Caffeine has attracted significant attention from researchers in the sports field due to its well-documented ergogenic effects across various athletic disciplines. As research on caffeine continues to progress, there has been a growing emphasis on evaluating caffeine dosage and administration methods. However, investigations into the optimal timing of caffeine intake remain limited. Therefore, this narrative review aimed to assess the ergogenic effects of caffeine administration at different times during the morning (06:00 to 10:00) and evening (16:00 to 21:00). The review findings suggest that circadian rhythms play a substantial role in influencing sports performance, potentially contributing to a decline in morning performance. Caffeine administration has demonstrated effectiveness in mitigating this phenomenon, resulting in ergogenic effects and performance enhancement, even comparable to nighttime levels. While the specific mechanisms by which caffeine regulates circadian rhythms and influences sports performance remain unclear, this review also explores the mechanisms underlying caffeine's ergogenic effects, including the adenosine receptor blockade, increased muscle calcium release, and modulation of catecholamines. Additionally, the narrative review underscores caffeine's indirect impact on circadian rhythms by enhancing responsiveness to light-induced phase shifts. Although the precise mechanisms through which caffeine improves morning performance declines via circadian rhythm regulation necessitate further investigations, it is noteworthy that the timing of caffeine administration significantly affects its ergogenic effects during exercise. This emphasizes the importance of considering caffeine intake timing in future research endeavors to optimize its ergogenic potential and elucidate its mechanisms.

Methamphetamine effects in zebrafish (Danio rerio) depend on behavioral endpoint, dose and test session duration.

Research using zebrafish (Danio rerio) has begun to provide novel information in many fields, including the behavioral pharmacology of drug use and misuse. There have been limited studies on the effects of methamphetamine in adult zebrafish and the parameters of exposure (dose, test session length) have not been well-documented. Behavior following drug exposure is generally measured during relatively short sessions (6-10 min is common) in a novel tank environment. Many procedural variables (isolation, netting, novel tank) elicit anxiety-like behavior that is most apparent during the initial portion of a test session. This anxiety-like behavior might mask the initial effects of methamphetamine. During longer test sessions, these anxiety-like responses would be expected to habituate and drug effects should become more apparent. To test this idea, we measured several locomotor activity responses for 50-min following a range of methamphetamine doses (0.1-3.0 mg/L via immersion in methamphetamine solution). Methamphetamine failed to alter swimming velocity, distance travelled, or freezing time. In contrast, methamphetamine produced a dose-dependent decrease in time spent in the bottom of the tank, an increase in the number of visits to the top of the tank, and an increase in the number of transitions along the sides of the tank. The effects of methamphetamine were apparent 10-20 min following exposure and generally persisted throughout the session. These findings indicate that longer test sessions are required to measure methamphetamine-induced changes in behavior in zebrafish, as has been shown in other laboratory animals. The results also suggest that anxiety-like responses associated with various procedural aspects (netting, isolation, novel test apparatus) likely interfere with the ability to observe many behavioral effects of methamphetamine in zebrafish. Based on the current results, habituation to testing procedures to reduce anxiety-like behaviors is recommended in determining the effects of methamphetamine in zebrafish.

From Consensus Statement to Pills to Pixels: New Innovations in Attention-Deficit/Hyperactivity Disorder Care.

Objectives: This review aims to present recent innovations and advancements in attention-deficit/hyperactivity disorder (ADHD) care, encompassing international consensus statement, new medication formulations, digital therapeutics, and neurostimulation devices. Methods: A comprehensive literature search of relevant articles published in the past five years was conducted, emphasizing the evidence base, efficacy, safety, and practical implications of these advancements. Results: The World Federation of ADHD Consensus Statement offers an updated diagnostic and treatment framework rooted in global scientific evidence. There are several newer ADHD medication formulations, including a nonstimulant (Viloxazine extended release) and the first transdermal amphetamine patch approved to treat ADHD. These options offer some unique benefits to personalize treatment based on symptom profile, lifestyle, preferences, and response. Digital tools offer additional means to restructure environments for individuals with ADHD, reducing impairment and reliance on others. In addition, digital therapeutics enhance access, affordability, personalization, and feasibility of ADHD care, complementing or augmenting existing interventions. Trigeminal nerve stimulation emerges as a well-tolerated nonpharmacological, device-based treatment for pediatric ADHD, with initial trials indicating effect sizes comparable to nonstimulant medications. Conclusions: These innovations in ADHD care represent clinically significant new treatment options and opportunities for personalized care. Health care professionals should integrate these developments into clinical practice, mindful of individual patient and family needs and preferences. Future research should assess long-term outcomes, cost-effectiveness, and acceptability of these innovations.

Neither Amphetamine nor Sub-Anesthetic Ketamine Treatment during Adolescence Impairs Devaluation in Rats Tested during Adulthood.

BACKGROUND: Much of the existing animal literature on the devaluation task suggests that prior repeated exposure to drugs of abuse during adulthood can impair goal-directed action, but the literature on human drug users is mixed. Also, the initiation of drug use often occurs during adolescence, but examinations of the effects of drug exposure during adolescence on behavior in the devaluation task are lacking. METHODS: We examined whether repeated exposure during adolescence to amphetamine (3 mg/kg injections every-other day from post-natal day 27-45) or ketamine (twice daily 30 mg/kg injections from post-natal day 35-44) would impair behavior in a devaluation test when tested drug-free in adulthood. Rats were trained to press a left lever with a steady cue-light above it for one reinforcer and a right lever with a flashing cue-light above it for a different reinforcer. We tested whether any impairments in goal-directed action could be overcome by compensation between strategies by giving rats information based on lever-location and cue-lights during the test that was either congruent (allowing compensation) or incongruent (preventing compensation between strategies) with the configurations during training. RESULTS: Our results provided no evidence for impairment of goal-directed action during adulthood after adolescent amphetamine or ketamine exposure. CONCLUSIONS: We discuss possible reasons for this discrepancy with the prior literature, including (1) the age of exposure and (2) the pattern in the previous literature that most previous demonstrations of drug exposure impairing devaluation in laboratory animals may be attributed to either drug-associated cues present in the testing environment and/or accelerated habit learning in tasks that predispose laboratory animals towards habit formation with extended training (with training procedures that should resist the formation of habits in the current experiment). However, additional research is needed to examine the effects of these factors, as well a potential role for the particular doses and washout periods to determine the cause of our finding of no devaluation impairment after drug exposure.

A Post-Hoc Analysis of Emotional Lability With Delayed-Release/Extended-Release Methylphenidate in Children Aged 6 to 12 Years of Age Participating in Two Phase 3 Clinical Trials.

OBJECTIVE: DR/ER-MPH (formerly HLD200) is an evening-dosed delayed-release and extended-release methylphenidate approved for the treatment of ADHD in patients ≥6 years. Post hoc analyses of two pivotal Phase 3 trials: HLD200-107 (NCT02493777) and HLD200-108 (NCT02520388) evaluated emotional lability (EL) with DR/ER-MPH treatment. METHODS: Differences in Conners Global Index-Parent (CGI-P) EL subscale scores and age- and gender-adjusted T-scores over an open-label titration phase (HLD200-107) and between treatment and placebo groups at endpoint (HLD200-108) were evaluated. RESULTS: In HLD200-107 (N = 117) mean CGI-P EL subscale scores improved from 5.3 to 1.3 (p < .0001) after 6 weeks; in HLD200-108 significant improvements were observed in the treatment group (n = 81) versus placebo (n = 80; 3.11 vs. 4.08; p = .0053). T-scores showed an improvement with DR/ER-MPH treatment in both trials. Few emotional adverse events (AEs) were reported. CONCLUSION: DR/ER-MPH treatment resulted in statistically significant improvements in EL to the level of non-ADHD peers as contextualized by T-scores.