Please tell me, could adhd come in different severities?

Of course: Most emotional or behavioral problems range from almost normal to very abnormal. Also, many mild cases pass on their own or the person adapts them into a personality style that works for them. If it can fit reasonably well into their lifestyle, it can be best to leave it alone. If it does not, find a good therapist for an eval and the least restrictive or intense treatment approach. Good luck.

Symptoms: Often tell a great deal about the impact that ADHD has in one's life. Response or non-response to medication can also be a factor. There are no specific categories like mild, moderate or severe so the rule of thumb I use is more symptoms, with little response to treatment or medication indicates that the disorder is stronger.