A team from Harvard Medical School and Massachusetts General Hospital conducted a six-week open-label trial of liquid-formulation extended-release methylphenidate (MPH-ER) to treat ADHD in adults with high-functioning autism spectrum disorder (HF-ASD). ASD is a lifelong disorder with deficits in social communication and interaction and restricted, repetitive behaviors. Roughly half of those diagnosed with ASD also are diagnosed with ADHD.

This was the first stimulant trial in adults with both ASD and ADHD. There were twelve male and three female participants, all with moderate to severe ADHD, and in their twenties, with IQ scores of at least 85.

Use of a liquid formulation enabled doses to be raised very gradually, starting with a daily dose of 5mg (1mL) and titrating up to 60mg over the first three weeks, then maintaining that level through the sixth week. Participants were reevaluated for ADHD symptoms every week during the six-week trial. Severity of ASD was assessed at the start, midpoint, and conclusion of the trial, as were other psychiatric symptoms.

Prior to the trial, researchers agreed on a combination of targets on two clinician-rated scoring systems that would have to be reached for treatment to be considered successful. One is a score of 2 or less on the CGI-S, a measure of illness severity, with scores ranging from 1 (normal, not at all ill) to 7 (most extremely ill). The other, a reduction of at least 30 percent in the AISRS score, which combines each of 18 symptoms of ADHD on a severity grid (0=not present; 3=severe; overall minimum score: 0; overall maximum score: 54).
At the conclusion of the trial, twelve of the fifteen patients (80 percent) met the preset conditions for success. Fully fourteen (93 percent) saw a ≥ 30 percent reduction in their AISRS score, while twelve scored ≤ 2 on illness severity.

However, when using the patient-rated ASRS scoring system, only five (33 percent) saw a ≥ 30 percent reduction in ADHD severity.

Thirteen participants (87 percent) reported at least one adverse event, and nine (60 percent) reported two or more. One reported a serious adverse event (attempted suicide) in a patient with multiple prior attempts. Because the attempt was not deemed due to medication they continued in and completed the trial. Seven participants experienced titration-limiting adverse events (headaches, palpitations, jaw pain, and insomnia). Headache was most frequent (53%), followed by insomnia and anxiety (33% each), and decreased appetite (27%).

During the trial, weight significantly decreased, while pulse significantly increased. There were no significant differences in other vital and cardiovascular measurements.

The authors concluded, “this OLT of short-term MPH-ER therapy documents that acute treatment with MPH-ER in young adults with ASD was associated with significant improvement in ADHD symptoms, mirroring the typically-expected magnitude of response observed in adults with only ADHD. Treatment with MPH-ER was well-tolerated, though associated with a higher than expected frequency of adverse events.”

They also cautioned, “The results of this study need to be considered in light of some methodological limitations. This was an open-label study; therefore, assessments were not blind to treatment. We did not employ a placebo control group and, therefore, cannot separate the effects of treatment from time or placebo effects. … firmer conclusions regarding the safety and efficacy of MPH-ER for the treatment of ADHD in HF-ASD populations await results from larger, randomized, placebo-controlled clinical trials.”

REFERENCES:
Gagan Joshi, Maura DiSalvo, Janet Wozniak, T. Atilla Ceranoglu, Amy Yule, Craig Surman, Ronna Fried, Maribel Galdo, Barbora Hoskova, Abigail Belser & Joseph Biederman, “A Prospective Open-Label Trial of Long-Acting Liquid Methylphenidate for the Treatment of Attention Deficit/Hyperactivity Disorder in Intellectually Capable Adults with Autism Spectrum Disorder,” The World Journal of Biological Psychiatry (2019) DOI: 10.1080/15622975.2019.1679392.