My son is 5 years old and has been diagnosed with ADHD.
Hi, and welcome
ADHD does affect aggression, really it affects all aspects of life in my opinion.
A child may HAVE ADHD, but it is not what they ARE. Never tell a child they ARE ADHD.
Yes, it definitely can contribute to aggression. Our son was kicked out of preschool because of aggressive behavior (and his other ADHD symptoms). Medication made all the difference in the world with him. As the doctor explained, "Concerta won't stop him from hitting, but it will give him the second to think it over first before HE decides to hit." At the beginning of first grade, when our son's Concerta dosage was too low and needed adjustment, he started hitting and pushing again. When we asked him why he did this to friends (he wasn't bullying at all, but taking play too far with kids he knows and likes), he said he felt like he couldn't control his body anymore. As soon as we upped to dosage, he was thriving again and the aggressive behavior ended.
Good luck with everything! I hope you find a treatment option that works for you and your family.Michelle