William and his mother return to your office 2 years later. His mother reports that her son’s behavior initially improved with PMT, but he has continued to have problems at home and at school. He continues to argue with adults, blames others for his misbehavior, and deliberately annoys his classmates at school. He is not able to pay attention in school and will often leave his seat during instruction. Getting out of the house in the morning takes 90 min as he will not follow directions or forgets what he has been asked to do. You diagnose William with ADHD and comorbid ODD and start him on methylphenidate. You recommend continued PMT.
Pharmacologic treatment
Medications are used as adjuncts to treat ADHD symptoms which may exacerbate ODD or aggression that may accompany ODD. Many pharmacological studies are confounded as they combine subjects with ODD and CD into a single group with the assumption that ODD represents a less severe or prodromal form of CD. Also, the outcome measure for effectiveness of medications for ODD is most commonly aggression which may be associated with ODD but is not a diagnostic criterion. Ideally, children with ADHD and ODD should be treated with monotherapy with the initial choice of a stimulant medication. Other medications with varying amounts of evidence to support efficacy for the treatment of oppositional symptoms in children with ODD include clonidine, guanfacine, atomoxetine, and risperidone. Most treatment effects of oppositional symptoms are highly correlated with those of ADHD core symptoms, making it difficult to independently assess the effectiveness of medications for ODD [30, 31]. See Table 2 for a summary of pharmacologic treatments.
Table 2 Medical therapies for oppositional symptoms
There has been a trend to add an atypical neuroleptic to a stimulant medication in the setting of poor response to monotherapy and severe aggression. This particular practice of polypharmacy for the treatment of child aggression was recently investigated and found to be somewhat efficacious [32•, 33•]. However, it is recommended that severely aggressive children with ODD be referred for management by a child psychiatrist.
Stimulant medications
Stimulants are the most widely studied medications for ADHD and generally felt to be most effective in children with ODD for treatment of core ADHD symptoms. A meta-analysis of the effects of stimulant medications on overt aggression (which included ODD) in children with ADHD found that there was a moderate to large effect (effect size = 0.84; 95 % confidence interval (CI), 0.696, 1.024; p value < 0.001) in reducing aggressive behaviors. However, this meta-analysis also revealed a significant variability in outcome among studies not accounted for by factors measured in the analysis and also included children with ODD and CD along with other aggressive behaviors into a single group [34].
Methylphenidate (MPH) has been shown to reduce ODD symptoms in children with ADHD in several studies [35–38]. However, the benefits were more widely reported on teacher rating scales than on parental rating scales. This may represent the negativity that can accompany a close long-term relationship colored by ODD. There are no recommendations that can be made as to the most efficacious form of MPH (immediate release vs. extended release systems) for oppositional symptoms as no direct comparisons have been made. However, one recent study describes the benefit of careful titration of once-daily MPH combined with behaviorally oriented psychosocial treatment for the target behavior of aggression in children with ADHD, comorbid ODD or CD, and a history of insufficient response to stimulants [39]. The authors claim that progression to the addition of atypical neuroleptics may be prevented by careful titration of MPH monotherapy.
There has been one randomized, double-blind, placebo-controlled trial of mixed amphetamine salts (MAS) that compared children with ADHD and ODD to those with ODD alone. This study found that oppositional symptoms improved in children with ADHD and ODD for a specific dosage of 30 mg/dose/day of extended release MAS. However, for the children with ODD only, there was no significant change in parental rating scores [40]. Another study showed similar effects of MAS on disruptive and antisocial behaviors in children with ADHD [38]. The aforementioned meta-analysis found no difference between MPH and MAS for the treatment of aggressive-related behaviors in children with ADHD [34].
The most common treatment-emergent adverse events (TEAEs) for MPH have been reported as abdominal pain, trouble sleeping, and loss of appetite [36, 38]. The most common TEAEs for MAS were reported as anorexia/decreased appetite, insomnia, headache, abdominal pain, and weight loss. No significant ECG or heart rate changes were noted [40].
Alpha-2 agonists
Clonidine and guanfacine are α-2 agonists shown to be effective for the treatment of ADHD. These medications are U.S. Food and Drug Administration (FDA) approved as monotherapy and adjuncts for children with ADHD with suboptimal response to stimulant monotherapy. In practice, they are most commonly used as ADHD monotherapy in children with side effects to stimulant medications, and occasionally as first-line agents in predominantly hyperactive children. There are very limited data on their effectiveness in specifically addressing oppositional symptoms.
A pilot study that compared MPH, MPH with clonidine, and clonidine alone for the treatment of children with ADHD with aggressive oppositional behaviors showed a benefit for all three therapies compared to baseline, but no difference among the three treatment arms was detected [41]. A recent meta-analysis of the effects of α-2 agonists as monotherapy and in combination therapy for ADHD (without formal diagnosis of ODD) examined reduction of oppositional symptoms as a secondary outcome measure. However, only two studies (one clonidine immediate release and one guanfacine extended release) met the inclusion criteria [30, 42]. The pooled standardized mean difference for oppositional symptoms was −0.44 (95 % CI, −0.69, −0.20; p < 0.001) [43•]. Another study, not included in the meta-analysis, demonstrated improvement of impulsive, oppositional, and defiant behaviors with MPH but not clonidine [44].
There is little research on α-2 agonists as adjuncts to stimulants for the reduction of oppositional symptoms for children diagnosed with both ADHD and ODD. A single study found a reduction in parent-reported conduct symptoms for clonidine as an adjunct to a stimulant in children with ADHD and ODD [45].
The most commonly reported adverse events for the α-2 agonists are somnolence, headache, sedation, fatigue, and upper abdominal pain. These effects are usually transient with resolution within 6 to 8 weeks [30, 46]. As α-2 agonists are also antihypertensive medications, there are also modest changes in blood pressure, pulse rate, and PR elongation on ECG [30].
Atomoxetine
Atomoxetine (ATX) is a selective norepinephrine reuptake inhibitor that is approved for the treatment of ADHD in adults and children 6 years of age and older. Similar to the α-2 agonists, ATX is a non-stimulant medication that is primarily used in children with ADHD who cannot tolerate or do not respond optimally to stimulant medications. Unlike stimulants and α-2 agonists, ATX is dosed by weight. Also dissimilar to stimulant therapy, it may take up to 8 weeks to see the full therapeutic effect of ATX.
A recent meta-analysis demonstrated that ATX was equivalent to MPH in reducing ADHD symptoms in children with ADHD and comorbid ODD, but did not specifically address effects on oppositionality [47•]. Another meta-analysis of children with ADHD showed a significant reduction in oppositional/defiant symptoms for ATX vs. placebo, but the effect was less robust than the improvement in ADHD symptoms. Oppositional/defiant symptoms improved similarly in both comorbid ADHD/ODD subjects and non-comorbid (subthreshold) ADHD subjects, and the authors concluded that the improvement in oppositional/defiant behavior was secondary to ATX’s effect on ADHD [48].
One often-referenced study demonstrated improvement in both ADHD and ODD symptoms, but higher doses of ATX (1.8 mg/kg/day) were required to reduce ADHD symptoms in subjects with comorbid ODD vs. those without (1.2 mg/kg/day) [31]. Other studies have concluded that decreases in oppositionality are highly correlated to the magnitude of improvement in core ADHD symptoms. ATX has been shown to reduce ADHD symptoms in children with and without ODD, and the presence of oppositional symptoms does not appear to affect the rate of relapse of ADHD symptoms. ATX may improve treatment of ODD indirectly through control of ADHD symptoms. Similarly, the presence of ODD symptoms is associated with an increased severity of ADHD. But the preponderance of evidence does not support a primary effect of ATX on oppositionality [49, 50].
The most commonly reported adverse effects for ATX include loss of appetite, nausea and/or vomiting, dyspepsia, and fatigue and/or weakness [48]. ATX has been associated with increased transaminases and acute liver failure in rare cases. It should be discontinued immediately in the case of jaundice or elevation of hepatic enzymes [51]. ATX’s chemical structure is similar to that of a selective serotonin reuptake inhibitor (SSRI), and it carries a boxed warning regarding the risk of suicidal ideation in children and adolescents.
Atypical antipsychotics
The atypical antipsychotics risperidone and aripiprazole are currently approved by the FDA for use in children and adolescents only for irritability associated with autism and for bipolar disorder. Other medications in this class are not currently approved for use in children. Data from the 1995–2010 National Ambulatory Medical Care Surveys revealed that antipsychotics were the fastest growing class of psychotropic medications in the pediatric population and that much of the increase in antipsychotic use in children and adolescents was for the treatment of DBDs, including ODD in spite of the fact that antipsychotics are not generally considered a first-line treatment for these conditions due to safety concerns. It was also noted that antipsychotic prescriptions from non-psychiatrist physicians increased significantly [52••].
The majority of research regarding the use of atypical antipsychotics for DBDs has focused on targeting aggressive behaviors, which are much more specific to CD than to ADHD/ODD. Many studies have also focused on children with both cognitive disabilities and disruptive behaviors, which is a distinct population from typically developing children with ADHD and comorbid oppositionality [52••]. Two recent meta-analyses considered the efficacy of atypical antipsychotics in treating DBDs. There is evidence of benefit for the use of risperidone in youth with subaverage IQ and disruptive behaviors. However, there was relatively weak evidence supporting the use of atypical antipsychotics in youth with average IQ and aggression and conduct problems [52••, 53••]. Conclusions were limited by heterogeneity of the study populations which included children with low IQ, but in general, the concurrent use of psychostimulants and psychosocial interventions is not adequately addressed in the current literature [53••].
There is some evidence that in children with ADHD and ODD who are not responding to parent training and optimized stimulant therapy, risperidone provides additional improvement in aggressive symptoms [32•, 33•].
The most commonly reported adverse effects for antipsychotic medications is significant increase in appetite resulting in overweight or obesity. Antipsychotics can cause metabolic side effects and extrapyramidal symptoms. Children should be routinely monitored for involuntary movements utilizing a tool such as the Abnormal Involuntary Movement Scale (AIMS) [54, 55].
Other medications
Lithium and first-generation antipsychotic medications have been shown to decrease aggressive behaviors in hospitalized children. Carbamazepine is frequently prescribed as a mood stabilizer, but has not been found to be superior to placebo in treating CD [56]. There is no clear role for these medications in the treatment of ADHD/ODD, particularly in the absence of aggressive behavior, and consultation with child psychiatry is recommended for their use in the treatment of disruptive behavior disorders.