Natural Product-Derived Treatments for Attention-Deficit/Hyperactivity Disorder: Safety, Efficacy, and Therapeutic Potential of Combination Therapy

Table 3

Clinical trials demonstrating efficacy of combination therapy of botanical agents and herbs/supplements with methylphenidate in treating ADHD.

Study		Methods	Participants	Outcomes	Comments
Lyon et al. [49]	Ginkgo biloba and Ginseng; Ginkgo biloba extract (50 mg) plus American ginseng, Panax quinquefolium (200 mg) twice/day; (combination product)	Open, pilot study	36 children, 3–17 years old with ADHD	Improvement of ADHD symptoms (hyperactivity, impulsiveness, and anxiety)	Five participants reported adverse events (increased ADHD symptoms, aggressiveness, sweating, headache, and tiredness), only 2 considered related to the study
Wang et al. [50]	Jingling oral and methylphenidate; Methylphenidate (10–40 mg/d)	Randomized, blinded study	ADHD children with transient tic disorder	Significant improvement of ADHD symptoms, as well as tics	Combination therapy more effective than methylphenidate alone in improving ADHD and tic symptoms
Ding et al. [51]	Yizhi and methylphenidate	Randomized, methylphenidate-controlled trial	210 children with hyperkinetic syndrome	Significant improvement in ADHD symptoms in those taking combination therapy compared to either given as monotherapy	Yizhi had fewer side effects when given alone or in combination than methylphenidate
Akhondzadeh et al. [47]	Zinc sulfate and methylphenidate	Randomized, double-blind, and methylphenidate + placebo controlled trial	44 children (26 boys, 18 girls), 5–11 years old with ADHD	Improved parent and teacher rating scale scores for those supplemented with zinc sulfate as an adjunct	Side effects reported: anxiety, loss of appetite, nausea, headache, abdominal pain, insomnia, and metallic taste