I took a variety of stimulants (Concerta, Adderall, Vyvanse, Dyanavel) all of which caused me have significant anxiety and irritability, and caused me to become hyperactive no matter how low the dosage (I do not have a problem with hyperactivity, only inattentive, ADD). Later on I found out I had a gene drug interaction to stimulant meds.. Then I moved onto non- stimulants. I took viloxazine which caused me to have suicidal thoughts and did not help. But I've had friends who have really benefitted and have not experienced these side effects.