Combined Methylphenidate and Selective Serotonin Reuptake Inhibitors in Adults With Attention-Deficit/Hyperactivity Disorder.

Importance: Depression is a common comorbidity of adult attention-deficit/hyperactivity disorder (ADHD), and the combination of methylphenidate and selective serotonin reuptake inhibitors (SSRIs) is a frequently prescribed treatment. However, there is limited clinical evidence on the safety of this medication combination in adults with ADHD. Objective: To evaluate the safety of administering a combination of SSRI and methylphenidate in adults with ADHD and comorbid depression. Design, Setting, and Participants: This cohort study obtained data from a nationwide claims database in South Korea from January 2016 to February 2021. Participants were adults aged 18 years or older with a diagnosis of ADHD and depressive disorder who were prescribed methylphenidate. Comparisons of 4 groups who received prescriptions were conducted: (1) SSRI plus methylphenidate (hereafter, SSRI) group vs methylphenidate-only group and (2) methylphenidate plus fluoxetine (hereafter, fluoxetine) group vs methylphenidate plus escitalopram (hereafter, escitalopram) group (compared to find a preferable treatment option). Data analysis was conducted between July and December 2023. Exposures: New users of the methylphenidate and SSRI combination among adults with both ADHD and depressive disorder. Main Outcomes and Measures: A total of 17 primary and secondary outcomes, including neuropsychiatric and other events, were assessed, with respiratory tract infection used as a control outcome. Groups were matched at a 1:1 ratio using a propensity score to balance confounders. A Cox proportional hazards regression model was used to calculate hazard ratio (HRs) and 95% CIs. Subgroup analysis by sex and sensitivity analyses in varying epidemiologic settings were conducted. Results: The study included 17 234 adults with ADHD (mean [SD] age at study entry, 29.4 [10.8] years; 9079 females [52.7%]). There was no difference in the risk of outcomes between the methylphenidate-only and SSRI groups, except for a lower risk of headache in the SSRI group (HR, 0.50; 95% CI, 0.24-0.99). In sensitivity analyses of fluoxetine vs escitalopram, the risk of hypertension (HR: 1:n matching, 0.26; 95% CI, 0.08-0.67) and hyperlipidemia (HR: 1:n matching, 0.23; 95% CI, 0.04-0.81) was lower in the fluoxetine group than in the escitalopram group. Conclusions and Relevance: Results of this study revealed no significant increase in adverse event risk associated with use of SSRI plus methylphenidate vs methylphenidate alone in adults with ADHD and comorbid depression. Instead, the combination was associated with a lower risk of headache.

Association between methylphenidate use and long-term cardiovascular risk in paediatric patients with attention deficit and hyperactivity disorder.

BACKGROUND: There have been concerns about the potential cardiovascular (CV) adverse effects associated with methylphenidate (MTH) use. However, only limited evidence exists on the long-term safety of MTH. OBJECTIVE: To evaluate whether MTH use is associated with long-term CV risk. METHODS: This was a retrospective cohort study using 2003-2017 data from the Health and Welfare Database in Taiwan. Patients newly diagnosed with attention deficit and hyperactivity disorder (ADHD) and between 3 and 18 years of age were included. Two treatment statuses were assessed: initial treatment ≥7 days and ≥180 days. Patients treated with MTH were compared with those receiving non-medication therapy. One-to-one propensity score matching was used to balance between-group differences. Study outcomes included major CV events, chronic CV disease, cardiogenic shock and all-cause mortality. Cox proportional hazard models were used to estimate HRs between the two groups. RESULTS: We began with 307 459 patients with ADHD. After exclusion, 224 732 patients were included in the final cohort. The results showed that compared with non-ADHD medication users, patients who were treated with MTH for more than 7 days had a similar risk of major CV events (HR 0.85, 95% CI 0.72 to 0.99; p=0.040). Identical trends were found in groups who were treated for more than 180 days (HR 0.83, 95% CI 0.69 to 1.00; p=0.050). The results of the sensitivity analyses were consistent with the main analyses across all groups and individual outcomes. CONCLUSION: Short-term MTH use did not increase CV risk among patients with ADHD. More evidence on long-term MTH use and risk of cardiogenic shock and death is warranted.

Appetite hormones, neuropsychological function and methylphenidate use in children with attention-deficit/hyperactivity disorder.

Appetite hormones may play a significant role in neuronal excitability and synaptic plasticity and may also affect brain function development. This study aimed to explore the role of appetite hormones in attention deficit/hyperactivity disorder (ADHD), including aspects of pathophysiology, pharmacotherapy, and side effects. We recruited 119 patients with ADHD who were undergoing methylphenidate treatment (ADHD+MPH), 77 unmedicated ADHD patients (ADHD-MPH), and 87 healthy controls. Blood samples were collected from all participants to examine serum levels of orexin A, ghrelin, leptin, and adiponectin. Behavioral symptoms were assessed using the Swanson, Nolan, and Pelham Rating Scale, and visual and auditory attention were evaluated using computerized neuropsychological tests. The side effects of methylphenidate treatment were measured using Barkley's Side Effects Rating Scale. Orexin levels in the control group were significantly higher than in the ADHD-MPH (p=0.037) and ADHD+MPH (p<0.001) groups; additionally, orexin levels in the ADHD-MPH group were significantly higher than in the ADHD+MPH group (p=0.032). Leptin levels in both the ADHD+MPH (p=0.011) and ADHD-MPH (p=0.011) groups were significantly lower than in the control group. Ghrelin levels were positively associated with auditory attention across all ADHD groups (p=0.015). Furthermore, ghrelin levels were positively correlated with methylphenidate dosage (p=0.024), and negatively correlated with methylphenidate side effects (p=0.044) in the ADHD+MPH group. These findings provide further insight into the relationships between appetite hormones, pharmacotherapy, and ADHD. Orexin A and leptin are associated with the etiology of ADHD, while orexin A and ghrelin play important roles in attention deficits and methylphenidate usage in ADHD.

Risk of Incident Psychosis and Mania With Prescription Amphetamines.

OBJECTIVE: Amphetamine prescribing has increased in the United States in recent years. Previous research identified an increased risk of incident psychosis with prescription amphetamines. The purpose of this study was to examine the impact of dose levels of prescription amphetamines on the risk of this rare but serious adverse outcome. METHODS: A case-control study using electronic health records was conducted to compare the odds of incident psychosis or mania with past-month exposure to prescription amphetamines. Case subjects were patients ages 16-35 hospitalized at McLean Hospital for incident psychosis or mania between 2005 and 2019. Control subjects were patients with an initial psychiatric hospitalization for other reasons, most commonly depression and/or anxiety. Amphetamine doses were converted to dextroamphetamine equivalents and divided into terciles. Secondary analyses evaluated the odds of psychosis or mania with methylphenidate use. RESULTS: Among 1,374 case subjects and 2,748 control subjects, the odds of psychosis and mania were increased for individuals with past-month prescription amphetamine use compared with no use (adjusted odds ratio=2.68, 95% CI=1.90-3.77). A dose-response relationship was observed; high doses of amphetamines (>30 mg dextroamphetamine equivalents) were associated with 5.28-fold increased odds of psychosis or mania. Past-month methylphenidate use was not associated with increased odds of psychosis or mania compared with no use (adjusted odds ratio=0.91, 95% CI=0.54-1.55). CONCLUSIONS: Although use of hospitalized control subjects excludes individuals with less severe disease, leading to selection bias, the study results suggest that caution should be exercised when prescribing high doses of amphetamines, with regular screening for symptoms of psychosis or mania.

Cumulative ADHD medication use and risk of type 2 diabetes in adults: a Swedish Register study.

BACKGROUND: Little is known about the impact of cumulative attention-deficit/hyperactivity disorder (ADHD) medication use on the risk of type 2 diabetes (T2D). OBJECTIVE: The objective is to examine the association between cumulative use of ADHD medication and risk of incident T2D. METHODS: A nested case-control study was conducted in a national cohort of individuals aged 18-70 years with incident ADHD (n=138 778) between 2007 and 2020 through Swedish registers. Individuals with incident T2D after ADHD were selected as cases (n=2355) and matched with up to five controls (n=11 681) on age at baseline, sex and birth year. Conditional logistic regression models examined the association between cumulative duration of ADHD medication use and T2D. FINDINGS: Compared with no use, a decreased risk of T2D was observed for those on cumulative use of ADHD medications up to 3 years (ORs: 03 years, 0.97 (95% CI, 0.84 to 1.12)). When investigating medication types separately, methylphenidate showed results similar to main analyses, lisdexamfetamine showed no association with T2D, whereas long-term (>3 years) use of atomoxetine was associated with an increased risk of T2D (OR: 1.44 (95% CI, 1.01 to 2.04)). CONCLUSION: Cumulative use of ADHD medication does not increase the risk for T2D, with the exception of long-term use of atomoxetine. CLINICAL IMPLICATIONS: Findings suggest that clinicians should be aware of the potential risk of T2D associated with the cumulative use of atomoxetine among patients with ADHD; however, further replication is strongly needed.

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.

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.

A matching-adjusted indirect comparison of centanafadine versus lisdexamfetamine, methylphenidate and atomoxetine in adults with attention-deficit/hyperactivity disorder: long-term safety and efficacy.

Aim: To compare long-term safety and efficacy outcomes of centanafadine versus lisdexamfetamine dimesylate (lisdexamfetamine), methylphenidate hydrochloride (methylphenidate) and atomoxetine hydrochloride (atomoxetine), respectively, in adults with attention-deficit/hyperactivity disorder (ADHD) using matching-adjusted indirect comparisons (MAICs). Patients & methods: Patient-level data from a centanafadine trial (NCT03605849) and published aggregate data from a lisdexamfetamine trial (NCT00337285), a methylphenidate trial (NCT00326300) and an atomoxetine trial (NCT00190736) were used. Patient characteristics were matched in each comparison using propensity score weighting. Study outcomes were assessed up to 52 weeks and included safety (rates of adverse events [AEs]) and efficacy (mean change from baseline in the Adult ADHD Investigator Symptom Rating Scale [AISRS] or ADHD Rating Scale [ADHD-RS] score). Results: In all comparisons of matched populations, risks of AEs were statistically significantly lower with centanafadine or non-different between centanafadine and comparator; the largest differences in AE rates included upper respiratory tract infection (risk difference in percentage points: 18.75), insomnia (12.47) and dry mouth (12.33) versus lisdexamfetamine; decreased appetite (20.25), headache (18.53) and insomnia (12.65) versus methylphenidate; and nausea (26.18), dry mouth (25.07) and fatigue (13.95) versus atomoxetine (all p < 0.05). Centanafadine had a smaller reduction in the AISRS/ADHD-RS score versus lisdexamfetamine (6.15-point difference; p < 0.05) and no statistically significant difference in the change in AISRS score versus methylphenidate (1.75-point difference; p = 0.13) and versus atomoxetine (1.60-point difference; p = 0.21). Conclusion: At up to 52 weeks, centanafadine showed significantly lower incidence of several AEs than lisdexamfetamine, methylphenidate and atomoxetine; efficacy was lower than lisdexamfetamine and non-different from methylphenidate and atomoxetine.

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.

Exploring Methylphenidate-Induced Intraocular Pressure: A Cautionary Tale in Pediatric ADHD Management.

OBJECTIVES: This case report explores the intricate relationship between methylphenidate (MTX) use and increased intraocular pressure (IOP) in a pediatric patient with a preexisting history of eye disease. Despite existing literature presenting cases of IOP elevation linked to MTX, a significant gap remains in understanding nuanced risk factors. METHODS: This case study used patients' medical records and a comprehensive literature review. RESULTS: A 6-year-old girl with attention deficit hyperactivity disorder and a family history of eye conditions exhibited elevated IOP after 12 days of MTX use, prompting discontinuation. The patient successfully transitioned to atomoxetine with normalized IOP and improved attention duration. CONCLUSIONS: Existing cases emphasize the potential link between sympathetic nerve activity and IOP elevation induced by central nervous system stimulants like MTX. Notably, the patient's high hyperopia contributed to the impact of MTX on IOP, suggesting the need for cautious use in susceptible individuals. This case underscores the importance of individualized treatment strategies, particularly in attention deficit hyperactivity disorder patients with family history and additional eye findings, emphasizing safety and comprehensive patient care.

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.

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.

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.

Association Between Single-Dose and Longer Term Clinical Response to Stimulants in Attention-Deficit/Hyperactivity Disorder: A Systematic Review of Randomized Controlled Trials.

Objectives: Stimulants, such as methylphenidate (MPH) and amphetamines, represent the first-line pharmacological option for attention-deficit/hyperactivity disorder (ADHD). Randomized controlled trials (RCTs) have demonstrated beneficial effects at a group level but could not identify characteristics consistently associated with varying individual response. Thus, more individualized approaches are needed. Experimental studies have suggested that the neurobiological response to a single dose is indicative of longer term response. It is unclear whether this also applies to clinical measures. Methods: We carried out a systematic review of RCTs testing the association between the clinical response to a single dose of stimulants and longer term improvement. Potentially suitable single-dose RCTs were identified from the MED-ADHD data set, the European ADHD Guidelines Group RCT Data set (https://med-adhd.org/), as updated on February 1, 2024. Quality assessment was carried out using the Cochrane Risk of Bias (RoB) 2.0 tool. Results: A total of 63 single-dose RCTs (94% testing MPH, 85% in children) were identified. Among these, only a secondary analysis of an RCT tested the association between acute and longer term clinical response. This showed that the clinical improvement after a single dose of MPH was significantly associated with symptom improvement after a 4-week MPH treatment in 46 children (89% males) with ADHD. The risk of bias was rated as moderate. A further RCT used near-infrared spectroscopy, thus did not meet the inclusion criteria, and reported an association between brain changes under a single-dose and longer term clinical response in 22 children (82% males) with ADHD. The remaining RCTs only reported single-dose effects on neuropsychological, neuroimaging, or neurophysiological measures. Conclusion: This systematic review highlighted an important gap in the current knowledge. Investigating how acute and long-term response may be related can foster our understanding of stimulant mechanism of action and help develop stratification approaches for more tailored treatment strategies. Future studies need to investigate potential age- and sex-related differences.

Recreational Cannabis Legalization: No Contribution to Rising Prescription Stimulants in the USA.

INTRODUCTION: There have been substantial increases in the use of Schedule II stimulants in the United States. Schedule II stimulants are the gold standard treatment for attention-deficit hyperactivity disorder (ADHD), but also carry the risk of addiction. Since the neurocognitive deficits seen in ADHD resemble those of chronic cannabis use, and the rise in stimulant use is incompletely understood, this study sought to determine if recreational cannabis (RC) legalization increased distribution rates of Schedule II stimulants. METHODS: The distribution of amphetamine, lisdexamfetamine, and methylphenidate were extracted from the ARCOS database of the Drug Enforcement Administration. The three-year population-corrected slopes of distribution before and after RC sales were evaluated. RESULTS: Total stimulant distribution rates were significantly higher in states with RC sales after (p=0.049), but not before (p=0.221), program implementation compared to states without RC. Significant effects of time (p<0.001) and RC sales status (p=0.045) were observed, while time x RC sales status interaction effects were not significant (p=0.406). DISCUSSION: RC legalization did not contribute to a more pronounced rise in Schedule II stimulant distribution in states. Future studies could explore the impact of illicit cannabis use on stimulant rates and the impact of cannabis sales on distribution rates of non-stimulant ADHD pharmacotherapies and ADHD diagnoses.