Psychiatric Annals

CME Article 

Determination of ADHD vs. Autism Spectrum Disorder

Laura N. Antar, MD, PhD

Abstract

CME Educational Objectives

1. Recognize that symptoms of inattention, impulsivity, and hyperactivity (attention-deficit/hyperactivity disorder [ADHD]) are common in patients with autism spectrum disorder (ASD), and ADHD symptoms should be considered an associated symptom domain of ASD.

2. Understand that although the ADHD-associated symptom domain of ASD is often a target for treatment with medication, treatment has a slightly lower response rate and slightly more side effects than in patients with ADHD alone.

3. Realize that pharmacologic treatment of the ADHD symptoms in patients with ASD may help them benefit from other interventions targeted at social deficits.

The patient is a 5-year, 6-month-old boy who has received comprehensive interventions for his sparse speech since he was 3 years old. He met most physical milestones on time, spoke words at 12 months, and phrases followed by sentences at 3 years. His IQ testing shows average intelligence. He has no fear of danger and will eat non-food items and lick objects. At times of transition, the patient can become combative with his mother and teachers, a daily occurrence that makes his mother consider home-schooling him for kindergarten, as he does not play with classmates nor is he learning. He cannot write the letters of his name, although he can spell it. The boy has trouble using spoons and is generally clumsy. He does not know the names of any children in his class, and although he insists on being watched by adults while he plays, he has no friends his age and does not play cooperatively or wait his turn.

Abstract

CME Educational Objectives

1. Recognize that symptoms of inattention, impulsivity, and hyperactivity (attention-deficit/hyperactivity disorder [ADHD]) are common in patients with autism spectrum disorder (ASD), and ADHD symptoms should be considered an associated symptom domain of ASD.

2. Understand that although the ADHD-associated symptom domain of ASD is often a target for treatment with medication, treatment has a slightly lower response rate and slightly more side effects than in patients with ADHD alone.

3. Realize that pharmacologic treatment of the ADHD symptoms in patients with ASD may help them benefit from other interventions targeted at social deficits.

The patient is a 5-year, 6-month-old boy who has received comprehensive interventions for his sparse speech since he was 3 years old. He met most physical milestones on time, spoke words at 12 months, and phrases followed by sentences at 3 years. His IQ testing shows average intelligence. He has no fear of danger and will eat non-food items and lick objects. At times of transition, the patient can become combative with his mother and teachers, a daily occurrence that makes his mother consider home-schooling him for kindergarten, as he does not play with classmates nor is he learning. He cannot write the letters of his name, although he can spell it. The boy has trouble using spoons and is generally clumsy. He does not know the names of any children in his class, and although he insists on being watched by adults while he plays, he has no friends his age and does not play cooperatively or wait his turn.

The patient is a 5-year, 6-month-old boy who has received comprehensive interventions for his sparse speech since he was 3 years old. He met most physical milestones on time, spoke words at 12 months, and phrases followed by sentences at 3 years. His IQ testing shows average intelligence. He has no fear of danger and will eat non-food items and lick objects. At times of transition, the patient can become combative with his mother and teachers, a daily occurrence that makes his mother consider home-schooling him for kindergarten, as he does not play with classmates nor is he learning. He cannot write the letters of his name, although he can spell it. The boy has trouble using spoons and is generally clumsy. He does not know the names of any children in his class, and although he insists on being watched by adults while he plays, he has no friends his age and does not play cooperatively or wait his turn.

The child hoards and lines up toys and attacks those who approach to play with his toys. He says “please” and “thank you” appropriately. He monopolizes teachers’ attention with his occasionally dangerous behavior (for example, he jumped off the stage of the auditorium, knocking over a classmate). His mother cannot keep up with him throughout the day. She had previously taken him to see a psychiatrist because of his lack of appropriate play with others and because of his extreme hyperactivity, impulsivity, and inattention, attributes about which his teachers also had complained. The psychiatrist diagnosed the boy with autism spectrum disorder (ASD). His mother states she “wasn’t ready to hear that,” and felt suspicious and confused. She took her son to a neurologist for a second opinion but received the diagnosis of attention-deficit/hyperactivity disorder (ADHD). The patient’s mother tried methylphenidate, which was prescribed by the neurologist, but the boy became extremely angry and combative, even though he admitted it helped his mind and body slow down. The mother discontinued his medication and made an appointment to see another psychiatrist.

The patient came well-dressed to the office, accompanied by his mother. He immediately established eye contact, one of the few times during the entire interview. He was able to separate from his mother in the office. The boy sat in a chair opposite the psychiatrist and in a few moments had tested all of the seats, tumbling backwards in a chair into which he had vigorously jumped. He was very apologetic. After taking Legos off the shelf, he asked if he could play with them, spilling the entire contents on the floor followed by all of the doll’s house contents. He seemed to ignore requests to play with one toy at a time. His self-stated goal was to build a tower. He lost interest after stacking three Legos and returned to the toy bin. The boy was able to hold some conversation, using full sentences to answer, even inquiring about the interviewer at times, but seldom finishing more than a three-sentence volley.

Diagnosis

Autism Spectrum Disorder

The diagnosis of autism spectrum disorder was made by a previous psychiatrist, and the mother now believed in its veracity. “Something is wrong with him,” she said. “He has absolutely no interest in friends, and his major passion is cars and roads, and he can’t sit still for a minute.” She also stated that she did not want to put her son on any medication, if possible, because “there’s no cure for autism.”

The mother was oriented to symptoms of autism and symptoms of ADHD. It was explained that autism is a pervasive developmental disorder affecting three key domains: 1) impaired communication; 2) social interaction; and 3) stereotyped or restricted/repetitive behaviors; whereas ADHD is defined by a deficit in attention, as well as hyperactivity and impulsivity.1 The diagnosis of autistic disorder was reconfirmed, with the patient displaying prominent symptoms of ADHD.

Currently, it is not possible through either DSM-IV-TR or ICD-102 nosology to diagnose both ASD and ADHD together. In order to diagnose autism, the symptoms cannot be attributable to other developmental disorders, including ADHD, as the ASD severity is considered the origin of the ADHD.1 This system exists despite the fact that ADHD symptoms may be the primary cause of morbidity. ASD is composed of individuals meeting the criteria for autistic disorder, Asperger’s syndrome, and pervasive developmental disorder, not otherwise specified.3 The Centers for Disease Control and Prevention estimate that about 0.9% of the US population is affected by ASD.4 ADHD is estimated to be present in approximately 5% of school-age children world-wide.5 In community-based studies and in the general population, between 13% and 50% of patients who have a primary clinical diagnosis of ASD also have ADHD symptoms, compared with between 20% and 85% in clinical samples.6 This can greatly impact the impairment experienced by patients who have both clusters of symptomatology, as the ADHD symptoms may continue to be undertreated.

Treatment

Only two drugs are approved by the US Food and Drug Administration for the reduction of ASD symptoms: risperidone and aripiprazole. These drugs target the irritability, aggression, and hyperactivity symptoms of autism; however, there are few controlled trials that assess the efficacy and tolerability of psycho-stimulants and other pharmacotherapy for ADHD with autism.

As reviewed in Davis and Kollins,7 the largest randomized, placebo-controlled crossover trial is the Research Units on Pediatric Psychopharmacology Autism Network (RUPP) study, which examined patients with autism diagnosis and hyperactivity. They found that stimulant medication was effective at diminishing hyperactivity and impulsivity in approximately 50% of individuals. This response rate is lower than the usual 70% to 80% found in children with ADHD alone. Furthermore, side effects were more pronounced in patients with ASD and ADHD symptoms than in patients with ADHD alone (see Sidebar).

Adverse Effects of Stimulant Medications in ASD Patients with Hyperactivity and Inattention

Table. Adverse Effects of Stimulant Medications in ASD Patients with Hyperactivity and Inattention

Methylphenidate was found to also improve joint attention initiation, self-regulation, and regulate affective states.7

Atomoxetine is a nonstimulant serotonin norepinephrine reuptake inhibitor that is often used in ADHD patients who cannot tolerate stimulant medication. It has been found to moderately regulate hyperactivity in two studies and impulsivity in another study, but not inattention in patients with ASD.8,9 Guanfacine is an alpha-2 adrenergic agonist, and the long-acting version, Intuniv (Shire Pharmaceuticals), is prescribed for ADHD. As described by Murray,10 the RUPP study also conducted an open trial of guanfacine and found that there was a 39% improvement over baseline, particularly in hyperactivity and impulsiveness. Parent scales also disclosed improvement in irritability, explosive behaviors, stereotypes, and social interaction.10

Conclusion

The boy’s mother was praised for teaching him to establish eye contact, and her son was commended for his good manners. Privately, his mother was discouraged from considering home-schooling and encouraged to pursue even more contact with other children. Her level of exhaustion and frustration with her son’s behavior was validated. An attempt to authenticate his experience was made with the mother, including the number of times he is told “no” in the span of a minute and his remorse for destruction of property and for his outbursts. It was discussed that his experiences probably make the world seem a critical place where it is impossible to succeed. His mother burst out crying stating, “he says he hates himself!”

Risks, benefits, and alternatives to these social and self-experiences vs. medications were discussed, and the patient was started first on risperidone. His mother and teachers found that this lessened his aggressive outbursts and difficulty with transitions. Encouraged, his mother requested nonstimulant medication for his ADHD. He was started on this medication and he benefited greatly. He had fewer hyperactive symptoms, and some social interactions improved. He was invited back to school for the next year, with a teacher’s aide assigned to him. The patient feels better about himself, and his mother states she no longer feels conflicted when she picks him up from school because she is genuinely glad to see him.

References

  1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: DSM-IV-TR. Arlington, VA; American Psychiatric Publishing; 2000.
  2. World Health Organization. ICD-10 Classifications of Mental and Behavioral Disorder: Clinical Descriptions and Diagnostic Guidelines. Geneva; 1994.
  3. American Psychiatric Association. Proposed revision for autism spectrum disorder. Available at: www.dsm5.org/ProposedRevisions/Pages/proposedrevision.aspx?rid=94. Accessed July 11, 2012.
  4. US Centers for Disease Control. Prevalence of autism spectrum disorders — Autism and Developmental Disabilities Monitoring Network, USA, 2006. Available at // www.cdc.gov/mmwr/preview/mmwrhtml/ss5810a1.htm. Accessed July 11, 2012.
  5. Polanczyk G, de Lima MS, Horta BL, Biederman J, Rhode LA. The worldwide prevalence of ADHD: a systematic review and metaregression analysis. Am J Psychiatry. 2007;164(6):942–948. doi:10.1176/appi.ajp.164.6.942 [CrossRef]
  6. Grzadzinski R, Di MA, Brady E, et al. Examining autistic traits in children with ADHD: does the autism spectrum extend to ADHD?J Autism Dev Disord. 2011; 41(9):1178–1191. doi:10.1007/s10803-010-1135-3 [CrossRef]
  7. Davis NO, Kollins SH: Treatment of co-occurring attention deficit/hyperactivity disorder and autism spectrum disorder. Neurotherapeutics. 2012Jun8 [Epub ahead of print]. doi:10.1007/s13311-012-0126-9 [CrossRef]
  8. Harfterkamp M, van de Loo-Neus G, Minderaa RB, et al. A Randomized double-blind study of atomoxetine versus placebo for attention deficit/hyperactivity disorder symptoms in children with autistic spectrum disorder. J Am Acad Child Adolesc Psychiatry. 2012; 51(7):733–741. doi:10.1016/j.jaac.2012.04.011 [CrossRef]
  9. Arnold LE, Aman MG, Cook AM, et al. Atomoxetine for hyperactivity in autism spectrum disorders: placebo-controlled crossover pilot trial. J Am Acad Child Adolesc Psychiatry. 2006;45(10):1196–1205. doi:10.1097/01.chi.0000231976.28719.2a [CrossRef]
  10. Murray M. Attention-deficit/hyperactivity disorder in the context of autism spectrum disorders. Curr Psychiatry Rep. 2010;12:382–388. doi:10.1007/s11920-010-0145-3 [CrossRef]
  11. Cortese S, Castelnau P, Morcillo C, et al. Psychostimulants for ADHD-like symptoms in individuals with autism spectrum disorders. Expert Rev Neurother. 2012Apr;12(4):461–473. doi:10.1586/ern.12.23 [CrossRef]

Adverse Effects of Stimulant Medications in ASD Patients with Hyperactivity and Inattention

Medication Adverse Effect
Psychostimulants (methylphenidate, dexmethyl-phenidate, dextroamphetamine, mixed amphetamine salts, dextromethamphetamine, lisdexamfetamine)

Appetite reduction

Difficulty falling asleep

Stomach or abdominal discomfort

Irritability

Emotional outbursts

Nonstimulants
Serotonin norepinephrine uptake inhibitors (atomoxetine) (Note: there are fewer side effects and better overall effects in patients with higher cognitive function)

Nausea

Somnolence

Irritability

Decrease in appetite

Fatigue

Early morning awakening

Alpha-2a adrenergic receptor agonists (guanfacine)

Sedation

Sleep disturbance

Irritability (more frustration intolerance than emotional outburst)

Authors

Laura N. Antar, MD, PhD, is an Assistant Professor of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine and Montefiore Medical Center, Autism and Obsessive-Compulsive Spectrum Program.

Address correspondence to: Laura N. Antar, MD, PhD, Autism and Obsessive-Compulsive Spectrum Program, Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine/Montefiore Medical Center, 3307 Bainbridge Avenue, Office #5, Bronx, NY 10467; fax: 718-653-7785; email: laura.antar@gmail.com.

Disclosure: Dr. Antar has no relevant financial relationships to disclose.

10.3928/00485713-20120806-08

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