IL2 and attention deficit-hyperactivity disorder: Additionally, studies in rodents have shown that administration of cytokines like interleukin-1β (IL-1β), interleukin-2 (IL-2), and interleukin-6 (IL-6) can cause neurotransmission changes similar to those seen in ADHD such as increased norepinephrine and reduced dopamine levels (13, 14).