Treating nicotine dependence by targeting attention-deficit/ hyperactivity disorder (ADHD) with OROS methylphenidate: the role of baseline ADHD severity and treatment response

The co-use of nicotine and prescription psychostimulants: A review of their behavioral and neuropharmacological interactions

BACKGROUND

Nicotine is commonly co-used with other psychostimulants. These high co-use rates have prompted much research on interactions between nicotine and psychostimulant drugs. These studies range from examination of illicitly used psychostimulants such as cocaine and methamphetamine to prescription psychostimulants used to treat attention deficit hyperactivity disorder (ADHD) such as methylphenidate (Ritalin™) and d-amphetamine (active ingredient of Adderall™). However, previous reviews largely focus on nicotine interactions with illicitly used psychostimulants with sparse mention of prescription psychostimulants. The currently available epidemiological and laboratory research, however, suggests high co-use between nicotine and prescription psychostimulants, and that these drugs interact to modulate use liability of either drug. The present review synthesizes epidemiological and experimental human and pre-clinical research assessing the behavioral and neuropharmacological interactions between nicotine and prescription psychostimulants that may contribute to high nicotine-prescription psychostimulant co-use.

METHODS

We searched databases for literature investigating acute and chronic nicotine and prescription psychostimulant interactions. Inclusion criteria were that participants/subjects had to experience nicotine and a prescription psychostimulant compound at least once in the study, in addition to assessment of their interaction.

RESULTS AND CONCLUSIONS

Nicotine clearly interacts with d-amphetamine and methylphenidate in a variety of behavioral tasks and neurochemical assays assessing co-use liability across preclinical, clinical, and epidemiological research. The currently available research suggests research gaps examining these interactions in women/female rodents, in consideration of ADHD symptoms, and how prescription psychostimulant exposure influences later nicotine-related outcomes. Nicotine has been less widely studied with alternative ADHD pharmacotherapy bupropion, but we also discuss this research.

Extended-release methylphenidate for attention deficit hyperactivity disorder (ADHD) in adults

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a psychiatric diagnosis increasingly used in adults. The recommended first-line pharmacological treatment is central nervous system (CNS) stimulants, such as methylphenidate, but uncertainty remains about its benefits and harms.

OBJECTIVES

To assess the beneficial and harmful effects of extended-release formulations of methylphenidate in adults diagnosed with ADHD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, nine other databases and four clinical trial registries up to February 2021. We searched 12 drug regulatory databases for clinical trial data up to 13 May 2020. In addition, we cross-referenced all available trial identifiers, handsearched reference lists, searched pharmaceutical company databases, and contacted trial authors.

SELECTION CRITERIA

Randomised, double-blind, parallel-group trials comparing extended-release methylphenidate formulations at any dose versus placebo and other ADHD medications in adults diagnosed with ADHD.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. We assessed dichotomous outcomes as risk ratios (RRs), and rating scales and continuous outcomes as mean differences (MDs) or standardised mean differences (SMDs). We used the Cochrane risk of bias tool to assess risks of bias, and GRADE to assess the certainty of the evidence. We meta-analysed the data using a random-effects model. We assessed three design characteristics that may impair the trial results' 'generalisability'; exclusion of participants with psychiatric comorbidity; responder selection based on previous experience with CNS stimulants; and risk of withdrawal effects. Our prespecified primary outcomes were functional outcomes, self-rated ADHD symptoms, and serious adverse events. Our secondary outcomes included quality of life, ADHD symptoms rated by investigators and by peers such as family members, cardiovascular variables, severe psychiatric adverse events, and other adverse events.

MAIN RESULTS

We included 24 trials (5066 participants), of which 21 reported outcome data for this review. We also identified one ongoing study. We included documents from six drug regulatory agencies covering eight trials. Twenty-one trials had an outpatient setting and three were conducted in prisons. They were primarily conducted in North America and Europe. The median participant age was 36 years. Twelve trials (76% of participants) were industry-sponsored, four (14% of participants) were publicly funded with industry involvement, seven (10% of participants) were publicly funded, and one had unclear funding. The median trial duration was eight weeks. One trial was rated at overall unclear risk of bias and 20 trials were rated at overall high risk of bias, primarily due to unclear blinding of participants and investigators, attrition bias, and selective outcome reporting. All trials were impaired in at least one of the three design characteristics related to 'generalisability'; for example, they excluded participants with psychiatric comorbidity such as depression or anxiety, or included participants only with a previous positive response to methylphenidate, or similar drugs. This may limit the trials' usefulness for clinical practice, as they may overestimate the benefits and underestimate the harms. Extended-release methylphenidate versus placebo (up to 26 weeks) For the primary outcomes, we found very low-certainty evidence that methylphenidate had no effect on 'days missed at work' at 13-week follow-up (mean difference (MD) -0.15 days, 95% confidence interval (CI) -2.11 to 1.81; 1 trial, 409 participants) or serious adverse events (risk ratio (RR) 1.43, CI 95% CI 0.85 to 2.43; 14 trials, 4078 participants), whereas methylphenidate improved self-rated ADHD symptoms (small-to-moderate effect; SMD -0.37, 95% CI -0.43 to -0.30; 16 trials, 3799 participants). For secondary outcomes, we found very low-certainty evidence that methylphenidate improved self-rated quality of life (small effect; SMD -0.15, 95% CI -0.25 to -0.05; 6 trials, 1888 participants), investigator-rated ADHD symptoms (small-to-moderate effect; SMD -0.42, 95% CI -0.49 to -0.36; 18 trials, 4183 participants), ADHD symptoms rated by peers such as family members (small-to-moderate effect; SMD -0.31, 95% CI -0.48 to -0.14; 3 trials, 1005 participants), and increased the risk of experiencing any adverse event (RR 1.27, 95% CI 1.19 to 1.37; 14 trials, 4214 participants). We rated the certainty of the evidence as 'very low' for all outcomes, primarily due to high risk of bias and 'indirectness of the evidence'. One trial (419 participants) had follow-up at 52 weeks and two trials (314 participants) included active comparators, hence long-term and comparative evidence is limited.

AUTHORS' CONCLUSIONS

We found very low-certainty evidence that extended-release methylphenidate compared to placebo improved ADHD symptoms (small-to-moderate effects) measured on rating scales reported by participants, investigators, and peers such as family members. Methylphenidate had no effect on 'days missed at work' or serious adverse events, the effect on quality of life was small, and it increased the risk of several adverse effects. We rated the certainty of the evidence as 'very low' for all outcomes, due to high risk of bias, short trial durations, and limitations to the generalisability of the results. The benefits and harms of extended-release methylphenidate therefore remain uncertain.

Influence of Substance Use Disorder on Treatment Retention of Adult-Attention-Deficit/Hyperactive Disorder Patients. A 5-Year Follow-Up Study

Attention-Deficit/Hyperactivity Disorder (ADHD) is the most widespread neurodevelopmental disorder, and it still persists into adulthood in 2–6% of the population. Psychiatric comorbidities are very common in adult ADHD (A-ADHD) patients; in particular, Substance Use Disorder (SUD) is found in 40% of these patients. Co-occurrence of ADHD and SUD is described as detrimental to clinical outcome by many authors, while only a few studies describe good clinical results in A-ADHD-SUD patients when they were treated for ADHD, both for the efficacy and the compliance of patients. In this study we tested to determine whether SUD can influence the treatment outcome of A-ADHD patients by correlating lifetime, past and current substance use in A-ADHD patients with their outcome (retention rate) during a 5-year follow-up of patients treated with stimulant and non-stimulant medications, using Kaplan–Meier survival analysis with overall and pairwise comparison. The association between demographic, symptomatological and clinical aspects with retention in treatment, adjusting for potential confounding factors, was summarized using Cox regression. After 5 years of observation, the cumulative treatment retention was 49.0%, 64.3% and 41.8% for A-ADHD patients without lifetime SUD (NSUD/A-ADHD), A-ADHD with past SUD (PSUD/A-ADHD) and A-ADHD with current SUD (CSUD/A-ADHD), respectively. Overall comparisons were not significant (Wilcoxon Rank-Sum (statistical) Test = 1.48; df = 2; p = 0.477). The lack of differences was confirmed by a Cox regression demonstrating that the ADHD diagnosis according to DIVA, gender, education, civil status, presence of psychiatric comorbidity, and psychiatric and ADHD familiarity; severity of symptomatological scales as evaluated by WHODAS, BPRS, BARRAT, DERS, HSRS, and ASRS did not influence treatment drop-out (χ2 22.30; df = 20 p = 0.324). Our A-ADHD-SUD patients have the same treatment retention rate as A-ADHD patients without SUD, so it seems that substance use comorbidity does not influence this clinical parameter.

Are non-abstinent reductions in World Health Organization drinking risk level a valid treatment target for alcohol use disorders in adolescents with ADHD?

•

Changes in WHO alcohol risk level are highly variable in youth treated for ADHD/SUD.

•

Achieving > 2-level reduction in WHO risk is linked to improvements in functioning.

•

Achieving > 2-level reduction in WHO risk is linked to decreased ADHD symptoms.

•

> 2-level reduction in WHO risk may be a valid non-abstinent AUD outcome in youth with ADHD/SUD.

Introduction

Abstinence from drinking represents the primary treatment target for alcohol use disorders (AUD) in youth, but few adolescents who engage in problematic drinking seek treatment. A reduction in World Health Organization (WHO) drinking risk level has been established as valid and reliable non-abstinent treatment target for AUD in adults but remains unstudied in youth.

Methods

The present study used data from the NIDA-CTN-0028 trial to examine associations between reductions in WHO drinking risk level and changes in global functioning and attention-deficit hyperactivity disorder (ADHD) symptoms during treatment in a sample of adolescents (ages 13–18 years) with ADHD and comorbid substance use disorder (SUD) (n = 297, 61% with AUD) receiving a 16-week intervention that combined ADHD pharmacotherapy (OROS-methylphenidate vs. placebo) and drug-focused cognitive-behavioral therapy.

Results

Shifts in drinking risk level during treatment were highly variable in adolescents treated for ADHD/SUD, and influenced by AUD diagnostic status. In the total sample, 15% of participants had a 2-level or greater reduction in WHO drinking risk level, with 59% and 24% showing no change or an increase in risk-level during treatment respectively. Achieving at least a 2-level change in WHO drinking risk level during treatment was associated with greater reduction in ADHD symptoms and better functional outcomes.

Conclusions

These findings parallel the adult AUD literature and provide preliminary support for the use 2-level reductions in WHO risk levels for alcohol use as a clinically valid non-abstinent treatment outcome for youth with ADHD and comorbid AUD.

Systematic Review and Meta-Analysis: Treatment of Substance Use Disorder in Attention Deficit Hyperactivity Disorder

BACKGROUND AND OBJECTIVES

Treating substance use disorder (SUD) in patients with co-occurring attention deficit hyperactivity disorder (ADHD) and SUD may lower medical, psychiatric, and social complications. We conducted a systematic review with meta-analysis to investigate the clinical benefits of pharmacological interventions to treat SUD in patients with ADHD.

METHODS

Articles were searched on Cochrane Central Register of Controlled Trials, PubMed, EBSCO, Google Scholar, Embase, Web of Science, and Ovid MEDLINE from 1971 to 2020. Data for SUD treatment as primary study endpoints and ADHD symptoms management as secondary outcomes were synthesized using random-effects model meta-analysis. Studies (N = 17) were included. The principal measure of effect size was the standardized mean difference (SMD). PROSPERO registration: CRD42020171646.

RESULTS

The pooled effect of pharmacological interventions compared with placebo was small for the reduction in substance use (SMD = 0.405, 95% confidence interval [CI]: [0.252, 0.557], P < .001), abstinence (SMD = 0.328, 95% CI: [0.149, 0.507], P < .001), craving (SMD = 0.274, 95% CI: [0.103, 0.446], P = .002), and the reduction in the frequency of ADHD symptoms (SMD = 0.420, 95% CI: [0.259, 0.582], P < .001). The pooled effect was moderate for the management of withdrawal symptoms (SMD = 0.577, 95% CI: [0.389, 0.764], P = .001]) and the decrease in the severity of ADHD symptoms (SMD = 0.533, 95% CI: [0.393, 0.672], P < .001).

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

The magnitude of benefits for pharmacological interventions varies. Despite some limitations, it was positive. This meta-analysis is the first to appraise the benefits of medications to treat SUD in ADHD. It is the groundwork for treatment and risk mitigation. (Am J Addict 2020;00:00-00).

ADHD Is Highly Prevalent in Patients Seeking Treatment for Cannabis Use Disorders

Objective: To estimate the prevalence of ADHD and determine an effective screening test for ADHD in a population-seeking treatment for cannabis use disorders. Method: The Conners Adult ADHD Diagnostic Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV; CAADID) was used to generate sensitivity and specificity data for ADHD screening tests, which were then administered to 99 participants seeking treatment for cannabis use disorders to estimate ADHD prevalence. Results: The prevalence estimated from the Wender Utah Rating Scale (WURS) was 45% (sensitivity = 0.88, sensitivity of 0.75), from the Conners Adult ADHD Rating Scale (CAARS) 34% (sensitivity = 0.80, specificity = 0.91), from the WURS + CAARS 36% (sensitivity = 0.71, specificity = 0.95), and from the Adult ADHD Self-Report Scale (ASRS) 46% (sensitivity = 0.61, specificity = 0.86). Conclusion: The prevalence of ADHD in adults seeking treatment for cannabis use disorders is estimated to be between 34% and 46%. The WURS paired with the CAARS provides excellent sensitivity and specificity for the diagnosis of ADHD in this population.

Differential Posttreatment Outcomes of Methylphenidate for Smoking Cessation for Individuals With ADHD

BACKGROUND AND OBJECTIVES

In a multisite, randomized study (CTN-0029), a 3-month course of Osmotic-Release Oral System Methylphenidate (OROS-MPH) improved smoking cessation in a group of patients with higher baseline severity in Attention-Deficit/Hyperactivity Disorder (ADHD). This treatment, however, worsened smoking cessation outcome in the group with lower baseline ADHD severity. We want to examine whether this differential treatment effect persisted after OROS-MPH was discontinued.

METHODS

We conducted a secondary analysis of the 1-month follow-up data from CTN-0029 after the discontinuation of OROS-MPH (N = 134). Nicotine patch was tapered during this month. We tested whether OROS-MPH had an effect on self-reported 7-day abstinence by week, as well as possible treatment by baseline ADHD severity interactions.

RESULTS

Abstinence diminished overall in time after the end of the treatment. In the high baseline severity group, patients who received OROS-MPH had an advantage in 7-day abstinence at week 15 (40% for OROS-MPH vs 20% for placebo, odds ratio = 2.63, P = .028). In the lower severity group (n = 121), no difference was detected (29% for OROS-MPH vs 32% for placebo, P = 1.00) between the two treatment groups. There was also a significant treatment by baseline ADHD severity interaction (P = .03).

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

OROS-MPH promotes abstinence beyond the course of treatment for patients with more severe ADHD, while the paradoxical effects in the lower baseline severity group is not persistent after medication discontinuation. Targeting ADHD in smoking cessation as a comorbidity therefore can have broader impact with more precise patient selection. (Am J Addict).

Pharmacotherapeutic strategies for the treatment of attention-deficit hyperactivity (ADHD) disorder with comorbid substance-use disorder (SUD)

INTRODUCTION

Substance use disorder (SUD) is very common amongst patients with attention deficit hyperactivity disorder (ADHD). The two disorders share partially overlapping features and SUD in ADHD is characterized by an early age of onset, high likelihood of poly-substance use, increased risk of suicide attempts, more hospitalizations, and scarce treatment adherence.

AREAS COVERED

This paper reviews randomized active comparator-controlled or placebo-controlled trials evaluating the use of pharmacotherapy in patients with ADHD and SUD. The authors include open label and observational studies.

EXPERT OPINION

Stimulant and non-stimulant treatments should be used to aid ADHD symptomatology in patients with SUD. SUD seems to be less responsive, suggesting a relative independence of the two conditions. For this reason, the association of ADHD-specific drugs and SUD-treatments should be recommended in a large proportion of patients suffering from both disorders. The rate and the quality of ADHD response to specific pharmacological treatments is highly variable, depending on the dose and the duration of the treatment, the age of the patient, and the severity and the chronicity of addiction. Further research is necessary to explore the divergences in treatment response of different ADHD subtypes in different subtypes of SUD.

How treatment improvement in ADHD and cocaine dependence are related to one another: A secondary analysis

BACKGROUND

Attention-deficit hyperactivity disorder (ADHD) is overrepresented among individuals seeking treatment for substance use disorders. We previously reported that treatment with extended release mixed amphetamine salts (MAS-XR) increased abstinence, compared to placebo, among patients with co-occurring ADHD and cocaine dependence. This secondary analysis investigates the temporal relationship between ADHD improvement and cocaine abstinence in the first six weeks of the trial.

METHODS

The study was a three-arm, randomized, double-blinded, placebo-controlled, 14-week trial comparing MAS-XR (60 mg or 80 mg daily) versus placebo among 126 participants with ADHD and cocaine dependence. An autoregressive cross-lagged structural equation model was fit and evaluated weekly ADHD improvement (defined as ≥30% reduction in the Adult ADHD Investigator Symptom Rating Scale) and urine-confirmed abstinence over the first six weeks.

RESULTS

The proportion of patients with each of the possible overall patterns of response was: ADHD improves before cocaine abstinence: 24%; Cocaine abstinence occurs before ADHD improvement: 12%; ADHD improvement and abstinence occur during the same week: 6%; ADHD improves but abstinence never achieved: 34%; Abstinence achieved but ADHD never improves: 6%; Neither ADHD improvement nor abstinence: 18%. A significant cross-lagged association was found; subjects with ADHD improvement at week 2 had significantly higher odds of cocaine abstinence at week 3 (p = .014).

CONCLUSION

When treating co-occurring ADHD and cocaine dependence with stimulant medication, abstinence is most likely preceded by improvement in ADHD, which tends to occur early with medication treatment. Other observed temporal patterns suggest the potential complexity of the relationship between ADHD and cocaine dependence.

Exploring longitudinal course and treatment-baseline severity interactions in secondary outcomes of smoking cessation treatment in individuals with attention-deficit hyperactivity disorder

BACKGROUND

A double blind, placebo-controlled randomized trial (NCT00253747) evaluating osmotic-release oral system methylphenidate (OROS-MPH) for smoking-cessation revealed a significant interaction effect in which participants with higher baseline ADHD severity had better abstinence outcomes with OROS-MPH while participants with lower baseline ADHD severity had worse outcomes.

OBJECTIVES

This current report examines secondary outcomes that might bear on the mechanism for this differential treatment effect.

METHODS

Longitudinal analyses were conducted to evaluate the effect of OROS-MPH on three secondary outcomes (ADHD symptom severity, nicotine craving, and withdrawal) in the total sample (N = 255, 56% Male), and in the high (N = 134) and low (N = 121) baseline ADHD severity groups.

RESULTS

OROS-MPH significantly improved ADHD symptoms and nicotine withdrawal symptoms in the total sample, and exploratory analyses showed that in both higher and lower baseline severity groups, OROS-MPH statistically significantly improved these two outcomes. No effect on craving overall was detected, though exploratory analyses showed statistically significantly decreased craving in the high ADHD severity participants on OROS-MPH. No treatment by ADHD baseline severity interaction was detected for the outcomes.

CONCLUSIONS

Methylphenidate improved secondary outcomes during smoking cessation independent of baseline ADHD severity, with no evident treatment-baseline severity interaction. Our results suggest divergent responses to smoking cessation treatment in the higher and lower severity groups cannot be explained by concordant divergence in craving, withdrawal and ADHD symptom severity, and alternative hypotheses may need to be identified.

Towards Precision Addiction Treatment: New Findings in Co-morbid Substance Use and Attention-Deficit Hyperactivity Disorders

Attention-deficit hyperactivity disorder (ADHD) and substance use disorders (SUDs) may have common etiologies. ADHD is more prevalent in patients with substance use disorders, and this pattern is consistent across different substances of abuse. Individuals with SUDs and ADHD exhibit significant variations in their clinical presentations. The developmental trajectory of ADHD to SUDs is complex: ADHD symptoms appear first in some patients but not in others. Many patients present with a heterogeneous collection of psychiatric and substance use co-morbidities, and these symptoms change over time. ADHD symptom severity is also highly variable, and more severe ADHD symptoms worsen co-morbid SUDs and complicate treatment. New longitudinal studies with innovative methods in high-risk populations and in community-based samples may clarify issues related to patient-treatment matching. When closely monitored, psychostimulant and other adjunct medications can be safely used to treat ADHD in this population, and such treatment may also improve outcome of SUDs. In particular, emerging evidence suggests individual-level tailoring ("precision medicine") approaches may represent a key pathway to improve clinical outcome.

Pharmacological Treatment of ADHD in Addicted Patients: What Does the Literature Tell Us?

LEARNING OBJECTIVES

After participating in this activity, learners should be better able to:• Evaluate pharmacologic treatment of attention deficit/hyperactivity disorder (ADHD) in patients with substance use disorder (SUD) • Assess the causes of the diminished efficacy of ADHD medication in patients with comorbid SUD OBJECTIVE: Substance use disorder (SUD) and attention-deficit/hyperactivity disorder (ADHD) frequently co-occur, and the presence of ADHD complicates the treatment of the addiction. Pharmacotherapy is a potent intervention in childhood and adult ADHD, but findings have been mixed in adolescent and adult ADHD patients with SUDs. This review focuses on several contributing factors and possible explanations, with implications both for future research and for clinical practice.

METHOD

This systematic review examined all randomized, placebo-controlled trials of pharmacotherapy for ADHD in adult and adolescent SUD patients.

RESULTS

The number of studies is limited, and several studies are hampered by qualitative flaws. The results, in general, are inconclusive for most medications studied, but more recent trials using psychostimulants in robust dosing have demonstrated significantly positive results.

CONCLUSION

In reviewing these trials, possible explanations relating to the particular characteristics and problems of this complex patient group are discussed. Several factors, including ADHD symptom severity, psychiatric comorbidity, persistent drug use, choice of medication, and concomitant psychosocial intervention, influence study results. Taking these factors into account may improve the likelihood of detecting significant effects in future research, as the recent positive trials have indicated, and may help in the appropriate selection of pharmacotherapy in clinical practice.

Nicotine Addiction and Psychiatric Disorders

Even though smoking rates have long been on the decline, nicotine addiction still affects 20% of the US population today. Moreover, nicotine dependence shows high comorbidity with many mental illnesses including, but are not limited to, attention deficit hyperactivity disorder, anxiety disorders, and depression. The reason for the high rates of smoking in patients with mental illnesses may relate to attempts to self-medicate with nicotine. While nicotine may alleviate the symptoms of mental disorders, nicotine abstinence has been shown to worsen the symptoms of these disorders. In this chapter, we review the studies from animal and human research examining the bidirectional relationship between nicotine and attention deficit hyperactivity disorder, anxiety disorders, and depression as well as studies examining the roles of specific subunits of nicotinic acetylcholine receptors (nAChRs) in the interaction between nicotine and these mental illnesses. The results of these studies suggest that activation, desensitization, and upregulation of nAChRs modulate the effects of nicotine on mental illnesses.

A systematic approach to subgroup analyses in a smoking cessation trial

BACKGROUND

Traditional approaches to subgroup analyses that test each moderating factor as a separate hypothesis can lead to erroneous conclusions due to the problems of multiple comparisons, model misspecification, and multicollinearity.

OBJECTIVE

To demonstrate a novel, systematic approach to subgroup analyses that avoids these pitfalls.

METHODS

A Best Approximating Model (BAM) approach that identifies multiple moderators and estimates their simultaneous impact on treatment effect sizes was applied to a randomized, controlled, 11-week, double-blind efficacy trial on smoking cessation of adult smokers with attention-deficit/hyperactivity disorder (ADHD), randomized to either OROS-methylphenidate (n = 127) or placebo (n = 128), and treated with nicotine patch. Binary outcomes measures were prolonged smoking abstinence and point prevalence smoking abstinence.

RESULTS

Although the original clinical trial data analysis showed no treatment effect on smoking cessation, the BAM analysis showed significant subgroup effects for the primary outcome of prolonged smoking abstinence: (1) lifetime history of substance use disorders (adjusted odds ratio [AOR] 0.27; 95% confidence interval [CI] 0.10-0.74), and (2) more severe ADHD symptoms (baseline score >36; AOR 2.64; 95% CI 1.17-5.96). A significant subgroup effect was also shown for the secondary outcome of point prevalence smoking abstinence--age 18 to 29 years (AOR 0.23; 95% CI 0.07-0.76).

CONCLUSIONS

The BAM analysis resulted in different conclusions about subgroup effects compared to a hypothesis-driven approach. By examining moderator independence and avoiding multiple testing, BAMs have the potential to better identify and explain how treatment effects vary across subgroups in heterogeneous patient populations, thus providing better guidance to more effectively match individual patients with specific treatments.

Toward personalized smoking-cessation treatment: Using a predictive modeling approach to guide decisions regarding stimulant medication treatment of attention-deficit/hyperactivity disorder (ADHD) in smokers

BACKGROUND AND OBJECTIVES

Osmotic-release oral system methylphenidate (OROS-MPH) did not show overall benefit as an adjunct smoking cessation treatment for adult smokers with ADHD in a randomized, placebo-controlled, multicenter clinical trial. A secondary analysis revealed a significant interaction between ADHD symptom severity and treatment-response to OROS-MPH, but did not account for other baseline covariates or estimate the magnitude of improvement in outcome if treatment were optimized. This present study addressed the gaps in how this relationship should inform clinical practice.

METHODS

Using data from the Adult Smokers with ADHD Trial (N = 255, six sites in five US States), we build predictive models to calculate the probability of achieving prolonged abstinence, verified by self-report, and expired carbon monoxide measurement. We evaluate the potential improvement in achieving prolonged abstinence with and without stratification on baseline ADHD severity.

RESULTS

Predictive modeling demonstrates that the interaction between baseline ADHD severity and treatment group is not affected by adjusting for other baseline covariates. A clinical trial simulation shows that giving OROS-MPH to patients with baseline Adult ADHD Symptom Rating Scale (ADHD-RS) >35 and placebo to those with ADHD-RS ≤35 would significantly improve the prolonged abstinence rate (52 ± 8% vs. 42 ± 5%, p < .001).

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

In smokers with ADHD, utilization of a simple decision rule that stratifies patients based on baseline ADHD severity can enhance overall achievement of prolonged smoking abstinence. Similar analysis methods should be considered for future clinical trials for other substance use disorders.

Predictors of treatment response in adolescents with comorbid substance use disorder and attention-deficit/hyperactivity disorder

Attention-Deficit/Hyperactivity Disorder (ADHD) frequently co-occurs with substance use disorder (SUD) and is associated with poor substance-use treatment outcomes. A trial evaluating osmotic-release oral system methylphenidate (OROS-MPH) for adolescents with ADHD and SUD, concurrently receiving behavioral therapy, revealed inconsistent medication effects on ADHD or SUD. Clinical care for this population would be advanced by knowledge of treatment outcome predictors. Data from the randomized placebo-controlled trial (n = 299) were analyzed. Significant treatment predictors included: 1) Substance use severity, associated with poorer ADHD and SUD outcomes, 2) ADHD severity, associated with better ADHD and SUD outcomes, 3) comorbid conduct disorder, associated with poorer ADHD outcomes, and 4) court-mandated status, associated with better SUD outcomes but poorer treatment completion. An interaction effect showed that OROS-MPH improved SUD outcomes in adolescents with comorbid conduct disorder compared to placebo. While severe SUD may require more intensive psychosocial treatment, OROS-MPH may improve substance treatment outcomes in adolescents with co-morbid attention and conduct problems.