The following study done by Dr. James T. McCracken et al tested the effects of stimulant and guanfacine monotherapies relative to combined treatment on cognitive functions important in ADHD.
- Age group: 7-14 yr old
- n= 182
- Duration: 8-week double-blind randomized controlled trials with three arm comparative trial.
Dose of medications:
- Guanfacine (GUAN): 1-3 mg/day
- d-methylphenidate (DMPH): 5-20 mg/day, or
- combination treatment with DMPH and GUAN (COMB)
Analyses examined treatment effects in 4 cognitive domains:
- working memory
- response inhibition
- reaction time, and
- reaction time variability.
- The treatments differed in effects on working memory but not other cognitive domains.
- Combination treatment improved working memory more than GUAN but was not significantly better than DMPH alone.
CLINICAL TIPS FROM THIS STUDY:
- Combined treatment with methylphenidate and guanfacine led to greater improvements in working memory than guanfacine alone.
- Combined treatment was not significantly superior to methylphenidate alone.
- These benefits were not observed on other cognitive domains for any of the treatments.
- This study corroborates the lack of efficacy of guanfacine on cognitive outcomes as a monotherapy, and further suggests it does not benefit cognition as an adjunct to stimulant treatment by direct comparison.
- J Am Acad Child Adolesc Psychiatry. 2016 Aug;55(8):667-73.
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Dr. Harvinder Singh, M.D. (Admin)
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