The research, set to be published in an upcoming issue of Nutritional Neuroscience, builds on previous studies linking the antioxidant ingredient to abating a host of conditions.
The present study showed Pycnogenol lowered adrenaline by 26.2 percent and the neurostimulant dopamine by 10.8 percent.
These hormones and stimulants affect processes and actions such as learning, cognition, attention and behaviour.
Children with Attention Deficit Hyperactivity Disorder (ADHD) have difficulty controlling their behavior and paying attention in the classroom.
"The findings of this study demonstrate a significant stress hormone lowering effect for a nutritional supplement for the first time," said Dr. Peter Rohdewald from the Institute of Pharmaceutical Chemistry at Germany's University of Munster and one of the authors of the study.
The National Institute of Mental Health estimates that between three and five percent of children have ADHD, or approximately two million children in the US.
"Pycnogenol's ability to naturally treat symptoms of ADHD is what makes this extract exceptionally pleasing to parents who may be uneasy about medicating their children with stimulant medications," said Dr. Rohdewald.
The study sampled 57 ADH|D outpatients at an average age of 9.5 years, at the Department of Child Psychology in Slovakia's Children's University Hospital.
Researchers measured the children's urine and blood samples.
Forty-one patients received branded Pycnogenol and 16 received placebo.
The participants were not given any other drugs or dietary supplements.
The Pycnogenol group received one mg of the pine bark substance or placebo for every kilogram of their body weight, on a daily basis each morning, for one month.
Stress hormones levels were extrapolated from urine samples taken before and after administering Pycnogenol or the placebo for a one-month period.
After a one-month discontinuation of treatment, a third urine sample was taken - revealing ADHD symptoms had recurred and stress hormone levels had again increased.
Pycnogenol has been the pioneer branded ingredient in the pine bark category and is made exclusively by Horphag Research in France.
The product is extracted from the bark of the Maritime pine that grows on the southern coast of France, and is currently used in over 400 dietary supplements, multi-vitamins and health products.
Natural Health Science in Hoboken, New Jersey, is the North American distributor for Pycnogenol.
The list of health conditions with symptoms that could be diminished by the pine bark extract includes hypertension, menopause, asthma, chronic venous insufficiency, osteoarthtitis, deep vein thrombosis, diabetes management and diabetic leg ulcers.