A Prospective Examination of the Association of Stimulant Medication History and Drug Use Outcomes among Community Samples of ADHD Youths

The effect of environment on cross-sensitization between methylphenidate and amphetamine in female rats

Methylphenidate (MPD) and amphetamine (AMP) are both psychostimulants that are often used to treat behavioral disorders. More recently, it has also been increasingly used illicitly for recreation as well as to improve intellectual performance. Many factors such as age, gender, genetic background, and environment govern the development of behavioral sensitization to MPD and cross-sensitization with other drugs, which are experimental behavioral markers indicating potential of substance dependence and abuse. This study examines the effects of the environment and age when MPD was exposed in adulthood alone as well as in adolescence into adulthood on cross-sensitization with AMP in female SD rats by randomizing animals to either receive the drug in a home cage or a test cage during adolescence, adulthood, or both. In a 34 day experiment, 16 groups of animals starting in adolescence were treated with saline on experimental day one (ED1), followed by a 6 day (ED2-ED7) treatment with either saline, 0.6 mg/kg AMP, 0.6, 2.5, or 10.0 mg/kg MPD. Experimental groups were then subject to a 3-day washout period (ED8-ED10) and then a retreatment with the respective drug on ED11 in adolescence (P-38 to P-49). Experiments continued in the same animal groups now in adulthood (P-60) with a saline treatment (ED1), followed by the same sequence of treatments in adolescence (ED2-ED11;P-61 to P-69). A rechallenge with the same AMP or MPD dose was performed on ED11 (P-70) followed by a single exposure to 0.6 mg/kg AMP on ED12 (P-71) to assess for cross sensitization between MPD and AMP. Animals treated with MPD in both adolescence and adulthood and in the last experimental day of AMP (ED12) showed higher intensity of cross-sensitivity between MPD and AMP as compared to animals treated with MPD only in adulthood. AMP and MPD treatment in adolescence and into adulthood in the home or test cage resulted in significantly higher responses to the drug as compared to those treated only in adulthood. Overall, we conclude that environmental alteration and adolescent exposure to MPD appeared to increase the risk of cross-sensitization to AMP in female SD rats i.e, using MPD in adolescence may increase the probability of becoming dependent on drugs of abuse. This further indicates that age, sex, and environment all influence the response to MPD and AMP, and further work is needed to elucidate the risks associated with MPD and AMP use.

The Impact of Pharmacotherapy of Childhood-Onset Psychiatric Disorders on the Development of Substance Use Disorders

Background and Objective: Child- and adolescent-onset psychopathology is known to increase the risk for developing substance use and substance use disorders (SUDs). While pharmacotherapy is effective in treating pediatric psychiatric disorders, the impact of medication on the ultimate risk to develop SUDs in these youth remains unclear. Methods: We conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) systematic review of peer-reviewed literature published on PubMed through November 2021, examining pharmacological treatments of psychiatric disorders in adolescents and young adults and their effect on substance use, misuse, and use disorder development. Results: Our search terms yielded 21 studies examining the impact of pharmacotherapy and later SUD in attention-deficit/hyperactivity disorder (ADHD), two studies on Major Depressive Disorder, and three studies on psychotic disorders. The majority of these studies reported reductions in SUD (N = 14 sides) followed by no effects (N = 10) and enhanced rates of SUD (N = 2). Studies in ADHD also reported that earlier-onset and longer-duration treatment was associated with the largest risk reduction for later SUD. Conclusions: Overall, pharmacological treatments for psychiatric disorders appear to mitigate the development of SUD, especially when treatment is initiated early and for longer durations. More studies on the development of SUD linked to the effects of psychotherapy alone and in combination with medication, medication initiation and duration, adequacy of treatment, non-ADHD disorders, and psychiatric comorbidity are necessary.

Oral Methylphenidate Treatment of an Adolescent ADHD Rat Model Does Not Alter Cocaine-Conditioned Place Preference during Adulthood: A Negative Report

The stimulant, methylphenidate (MPH), is commonly used to treat attention deficit hyperactivity disorder (ADHD) and has been increasingly prescribed for school age children and adolescents. Concerns regarding its long-term effects on later substance use disorders (SUDs) have been raised. Previous animal studies have produced contradictory results regarding whether early exposure to MPH increases or protects against SUD in adulthood. The goal of our study was to determine if clinically relevant doses of MPH during adolescence alter cocaine responsiveness in adulthood in a rat model of ADHD, the spontaneous hypertensive rat (SHR). We pretreated SHRs with saline or MPH (2.5 mg/kg once or twice day) via oral gavage during their dark cycle from postnatal day 35 (p35) to p44. Adult rats (p80) were assessed in an eight-session cocaine-conditioned place preference test (CPP). Four doses of cocaine were administered via intraperitoneal injection (i.p.) during the conditioning sessions: 1, 5, 10 and 20 mg/kg. Once per day MPH treatment had a small sensitizing effect on baseline general locomotor activity in a novel environment at p80 as well as a limited suppressive effect on reward-specific locomotor activity as measured by the decreased preference to enter the cocaine-paired chamber. This treatment did not have any effect on the amount of time that rats chose to spend in the cocaine-paired chamber. Twice per day MPH treatment had no effect on locomotion or drug-preference. Our results suggest that MPH treatment of ADHD rats during adolescence does not alter preference for cocaine in adulthood.

Psychiatric comorbid patterns in adults with attention-deficit hyperactivity disorder: Treatment effect and subtypes

Psychiatric comorbidities are common in individuals with attention-deficit/hyperactivity disorder (ADHD). In this study, we sought to evaluate the effects of medication and childhood ADHD subtypes on psychiatric comorbidities among adults with ADHD as compared to healthy adult controls. We assessed 121 drug-naïve adults with ADHD, 93 treated adults with ADHD, and 145 healthy controls (age 18-36 years) using semi-structured psychiatric interviews, intelligence tests, and medical records. Drug-naïve adults with ADHD had more comorbidities than treated adults with ADHD and controls. Childhood ADHD-combined subtype, relative to ADHD-inattentive subtype, was associated with higher risks of comorbidities. Current medication treatment was associate with a higher risk for anxiety disorders, and longer treatment duration was associated with lower risks of mood disorders and sleep disorders. Our results indicate that no medication treatment, short treatment duration, and childhood ADHD-combined subtype are associated with increased risks for psychiatric comorbidities among adults with ADHD.

Do Stimulants Reduce the Risk for Alcohol and Substance Use in Youth With ADHD? A Secondary Analysis of a Prospective, 24-Month Open-Label Study of Osmotic-Release Methylphenidate

OBJECTIVE

The purpose of this study was to examine the impact of stimulant treatment on risk for alcohol and illicit drug use in adolescents with ADHD.

METHOD

Analysis of data derived from a prospective open-label treatment study of adolescent ADHD ( n = 115, 76% male), and a historical, naturalistic sample of ADHD ( n = 44, 68% male) and non-ADHD youth ( n = 52, 73% male) of similar age and sex. Treatment consisted of extended-release methylphenidate in the clinical trial or naturalistic stimulant treatment. Self-report of alcohol and drug use was derived from a modified version of the Drug Use Screening Inventory.

RESULTS

Rates of alcohol and drug use in the past year were significantly lower in the clinical trial compared with untreated and treated naturalistic ADHD comparators, and similar to rates in non-ADHD comparators.

CONCLUSION

Well-monitored stimulant treatment may reduce the risk for alcohol and substance use in adolescent ADHD.

A randomized clinical trial of family therapy in juvenile drug court

The objective of this article is to examine the effectiveness of 2 theoretically different treatments delivered in juvenile drug court--family therapy represented by multidimensional family therapy (MDFT) and group-based treatment represented by adolescent group therapy (AGT)--on offending and substance use. Intent-to-treat sample included 112 youth enrolled in juvenile drug court (primarily male [88%], and Hispanic [59%] or African American [35%]), average age 16.1 years, randomly assigned to either family therapy (n = 55) or group therapy (n = 57). Participants were assessed at baseline and 6, 12, 18 and 24 months following baseline. During the drug court phase, youth in both treatments showed significant reduction in delinquency (average d = .51), externalizing symptoms (average d = 2.32), rearrests (average d = 1.22), and substance use (average d = 4.42). During the 24-month follow-up, family therapy evidenced greater maintenance of treatment gains than group-based treatment for externalizing symptoms (d = 0.39), commission of serious crimes (d = .38), and felony arrests (d = .96). There was no significant difference between the treatments with respect to substance use or misdemeanor arrests. The results suggest that family therapy enhances juvenile drug court outcomes beyond what can be achieved with a nonfamily based treatment, especially with respect to what is arguably the primary objective of juvenile drug courts: reducing criminal behavior and rearrests. More research is needed on the effectiveness of juvenile drug courts generally and on whether treatment type and family involvement influence outcomes.

TRIAL REGISTRY NAME

Clinical Trials.gov, Identified NCT01668303.

The Association Between Attention-Deficit Hyperactivity Disorder and Nicotine Use Among Adolescents and Young Adults

Previous research indicates that youth with ADHD are more susceptible to nicotine use compared to those without ADHD and one explanation for this association is the self-medication theory. The present study examines nicotine use in a prospective sample derived from a community sampling procedure rather than a clinical setting. Nicotine use was measured through young adulthood (mean ages: 18, 20 and 22) and three groups were compared based on childhood status: ADHD-only, ADHD-extemalizers and control groups. Results indicated that at all three data points, individuals with childhood ADHD plus an externalizing disorder reported higher nicotine use on all variables compared to the ADHD group absent of an externalizing disorder and the comparison group of non-ADHD youth. The group differences were significant even after controlling for possible confounding variables (age, gender, and current treatment with psychostimulant medication). Study results are discussed in light of the self-medication hypothesis and of the importance of including nicotine prevention programs for adolescents and young adults with ADHD and externalizing problems.

Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a neurobiological condition of childhood onset with the hallmarks of inattention, impulsivity, and hyperactivity. Inattention includes excessive daydreaming, disorganization, and being easily distracted. Impulsivity manifests as taking an action before fully thinking of the consequences. Hyperactivity includes an excessive rate of speech and motor activity. Complications of ADHD include academic failure, low self-esteem, poor work performance, substance abuse, criminal justice issues, and social problems. ADHD is predominately due to decreased activity in the frontal lobe. Dopamine and norepinephrine are the main neurotransmitters involved in the pathophysiology of ADHD. Pharmacological treatment of ADHD includes psychostimulants, norepinephrine reuptake inhibitors, α2 agonists, bupropion, and monoamine oxidase inhibitors. The most effective medications are the psychostimulants. Nonpharmacological treatment of ADHD includes coaching, providing structure, academic accommodations, and work accommodations.

Stimulant ADHD medication and risk for substance abuse

BACKGROUND

There are persistent concerns of long-term effects of stimulant ADHD medication on the development of substance abuse.

METHODS

Using Swedish national registers, we studied all individuals born between 1960 and 1998 and diagnosed with ADHD (26,249 men and 12,504 women). We investigated the association between stimulant ADHD medication in 2006 and substance abuse during 2009. Substance abuse was indexed by substance-related death, crime, or hospital visits.

RESULTS

ADHD medication was not associated with increased rate of substance abuse. Actually, the rate during 2009 was 31% lower among those prescribed ADHD medication in 2006, even after controlling for medication in 2009 and other covariates (hazard ratio: 0.69; 95% confidence interval: 0.57-0.84). Also, the longer the duration of medication, the lower the rate of substance abuse. Similar risk reductions were suggested among children and when investigating the association between stimulant ADHD medication and concomitant short-term abuse.

CONCLUSIONS

We found no indication of increased risks of substance abuse among individuals prescribed stimulant ADHD medication; if anything, the data suggested a long-term protective effect on substance abuse. Although stimulant ADHD medication does not seem to increase the risk for substance abuse, clinicians should remain alert to the potential problem of stimulant misuse and diversion in ADHD patients.

Stimulant treatment of ADHD and cigarette smoking: a meta-analysis

BACKGROUND AND OBJECTIVE

Individuals with attention-deficit/hyperactivity disorder (ADHD) have a significantly higher risk of cigarette smoking. The nature of the relationship between smoking and psychostimulant medications commonly used to treat ADHD is controversial. Our objective was to examine the relationship between stimulant treatment of ADHD and cigarette smoking by using meta-analysis, and to identify study and sample characteristics that moderate this relationship.

METHODS

Literature searches on PubMed and PsycInfo databases identified published studies for inclusion. Included studies compared cigarette smoking outcomes for stimulant-treated and untreated ADHD individuals. Seventeen studies met inclusion criteria, and 14 (total n = 2360) contained sufficient statistical information for inclusion in the meta-analysis. Two authors extracted odds ratios or frequencies of smokers in the treatment or nontreatment groups, and coded study characteristics including sample source, percentage of male participants, follow-up length, treatment consistency, type of smoking measure, prospective study, and controlling for comorbidities.

RESULTS

Meta-analysis revealed a significant association between stimulant treatment and lower smoking rates. Meta-regression indicated that effect sizes were larger for studies that used clinical samples, included more women, measured smoking in adolescence rather than adulthood, conceptualized stimulant treatment as consistent over time, and accounted for comorbid conduct disorder.

CONCLUSIONS

Nearly all studies were naturalistic, precluding causal inferences. Available data were insufficient to examine additional influences of patient demographics, treatment effectiveness, or other comorbidities. Consistent stimulant treatment of ADHD may reduce smoking risk; the effect was larger in samples with more severe psychopathology. Implications for further research, treatment of ADHD, and smoking prevention are discussed.

A longitudinal study of childhood ADHD and substance dependence disorders in early adulthood

Attention deficit hyperactivity disorder (ADHD) is a childhood disorder that is associated with many behavioral and social problems. These problems may continue when an individual continues to meet criteria for ADHD as an adult. In this study, we describe the outcome patterns for three different groups: individuals who had ADHD as children, but no longer meet criteria as adults (Childhood-Limited ADHD, n = 71); individuals who met ADHD criteria as children and continue to meet criteria as young adults (Persistent ADHD n = 79); and a control group of individuals who did not meet ADHD diagnostic criteria in childhood or adulthood (n = 69). Groups were compared with examine differences in change in rates of alcohol, marijuana, and nicotine dependence over 3 time points in young adulthood (mean ages 18, 20, and 22 years). The method used is notable as this longitudinal study followed participants from childhood into young adulthood instead of relying on retrospective self-reports from adult participants. Results indicated that there were no significant group differences in change in rates of substance dependence over time. However, individuals whose ADHD persisted into adulthood were significantly more likely to meet DSM-IV criteria for alcohol, marijuana, and nicotine dependence across the 3 time points after controlling for age, sex, childhood stimulant medication use, and childhood conduct problems. Implications of these findings, as well as recommendations for future research, are discussed.

Methylphenidate does not influence smoking-reinforced responding or attentional performance in adult smokers with and without attention deficit hyperactivity disorder (ADHD)

Individuals with Attention Deficit Hyperactivity Disorder (ADHD) smoke cigarettes at rates higher than the general population and questions have been raised about how stimulant drugs-the frontline pharmacological treatment for ADHD-influence smoking risk and behavior in those with ADHD. In the present study adult regular smokers with (n = 16) and without (n = 17) ADHD participated in 3 experimental sessions in which they completed a Progressive Ratio (PR) task to measure the relative reinforcing effects of cigarette smoking and money after oral administration of placebo and 2 active doses of methylphenidate (10 mg and 40 mg). We also measured attention and inhibitory control via a Continuous Performance Test (CPT). Methylphenidate had no effect on smoking-reinforced responding, attention, or inhibitory control in either group. Attention and inhibitory control were associated with smoking-reinforced responding, but unsystematically and only in the non-ADHD group. Several design features, such as the value of the monetary response option, the PR schedule, and the potential effects of smoking on attention and inhibitory control, could have contributed to the negative findings and are discussed as such. Although inconsistent with some previous human laboratory studies of stimulant drugs and smoking, results are consistent with recent trials of stimulant drugs as adjuncts for smoking cessation in adult smokers with ADHD. In general, methylphenidate at mild and moderate doses did not influence the relative reinforcing effects of cigarette smoking in adults with and without ADHD.

Stimulant medication and substance use outcomes: a meta-analysis

IMPORTANCE

Psychostimulant medication is an efficacious treatment for childhood attention-deficit/hyperactivity disorder, yet controversy remains regarding potential iatrogenic effects of stimulant medication, particularly with respect to increasing susceptibility to later substance use disorders. However, stimulant treatment was previously reported to reduce the risk of substance problems.

OBJECTIVE

To meta-analyze the longitudinal association between treatment with stimulant medication during childhood and later substance outcomes (ie, lifetime substance use and substance abuse or dependence).

DATA SOURCES

Studies published between January 1980 and February 2012 were identified using review articles, PubMed, and pertinent listservs.

STUDY SELECTION

Studies with longitudinal designs in which medication treatment preceded the measurement of substance outcomes.

DATA EXTRACTION AND SYNTHESIS

Odds ratios were extracted or provided by the study authors. Odds ratios were obtained for lifetime use (ever used) and abuse or dependence status for alcohol, cocaine, marijuana, nicotine, and nonspecific drugs for 2565 participants from 15 different studies.

MAIN OUTCOMES AND MEASURES

Random-effects models estimated the overall association, and potential study moderators were examined.

RESULTS

Separate random-effects analyses were conducted for each substance outcome, with the number of studies ranging from 3 to 11 for each outcome. Results suggested comparable outcomes between children with and without medication treatment history for any substance use and abuse or dependence outcome across all substance types.

CONCLUSIONS

These results provide an important update and suggest that treatment of attention-deficit/hyperactivity disorder with stimulant medication neither protects nor increases the risk of later substance use disorders.

Adolescence methylphenidate treatment in a rodent model of attention deficit/hyperactivity disorder: dopamine transporter function and cellular distribution in adulthood

Attention deficit/hyperactivity disorder (ADHD) is attributed to dysfunction of the prefrontal cortex. Methylphenidate, an inhibitor of dopamine and norepinephrine transporters (DAT and NET, respectively), is a standard treatment for ADHD. The Spontaneously Hypertensive Rat (SHR) is a well-established animal model of ADHD. Our previous results showed that methylphenidate treatment in adolescent SHR enhanced cocaine self-administration during adulthood, and alterations in DAT function in prefrontal cortex play a role in this response. Importantly, prefrontal cortex subregions, orbitofrontal cortex (OFC) and medial prefrontal cortex (mPFC), have been shown to have distinct roles in ADHD and cocaine self-administration. In the current study, SHR, Wistar-Kyoto (WKY) and Wistar (WIS) rats received a therapeutically relevant dose of methylphenidate (1.5mg/kg, p.o.) or vehicle during adolescence and then OFC and mPFC DAT function and cellular expression were assessed during adulthood. In both OFC and mPFC, no strain differences in Vmax or Km for dopamine uptake into synaptosomes were found between vehicle-treated SHR, WKY and WIS. Methylphenidate increased DAT Vmax in SHR mPFC and decreased DAT Vmax in WKY OFC. Also, methylphenidate decreased DAT Km in WIS OFC. Further, methylphenidate did not alter DAT cellular localization, indicating that methylphenidate treatment during adolescence regulated DAT function in SHR mPFC in a trafficking-independent manner. Thus, the increase in mPFC DAT function was an SHR-specific long term consequence of methylphenidate treatment during adolescence, which may be responsible for the treatment-induced alterations in behavior including the observed increases in cocaine self-administration.

Adolescent substance use in the multimodal treatment study of attention-deficit/hyperactivity disorder (ADHD) (MTA) as a function of childhood ADHD, random assignment to childhood treatments, and subsequent medication

OBJECTIVE

To determine long-term effects on substance use and substance use disorder (SUD), up to 8 years after childhood enrollment, of the randomly assigned 14-month treatments in the multisite Multimodal Treatment Study of Children with Attention-Deficit/Hyperactivity Disorder (MTA; n = 436); to test whether medication at follow-up, cumulative psychostimulant treatment over time, or both relate to substance use/SUD; and to compare substance use/SUD in the ADHD sample to the non-ADHD childhood classmate comparison group (n = 261).

METHOD

Mixed-effects regression models with planned contrasts were used for all tests except the important cumulative stimulant treatment question, for which propensity score matching analysis was used.

RESULTS

The originally randomized treatment groups did not differ significantly on substance use/SUD by the 8-year follow-up or earlier (mean age = 17 years). Neither medication at follow-up (mostly stimulants) nor cumulative stimulant treatment was associated with adolescent substance use/SUD. Substance use at all time points, including use of two or more substances and SUD, were each greater in the ADHD than in the non-ADHD samples, regardless of sex.

CONCLUSIONS

Medication for ADHD did not protect from, or contribute to, visible risk of substance use or SUD by adolescence, whether analyzed as randomized treatment assignment in childhood, as medication at follow-up, or as cumulative stimulant treatment over an 8-year follow-up from childhood. These results suggest the need to identify alternative or adjunctive adolescent-focused approaches to substance abuse prevention and treatment for boys and girls with ADHD, especially given their increased risk for use and abuse of multiple substances that is not improved with stimulant medication. Clinical trial registration information-Multimodal Treatment Study of Children With Attention Deficit and Hyperactivity Disorder (MTA); http://clinical trials.gov/; NCT00000388.