Zuccino provides several accounts of attacks by the feedaeyeen as the 2nd Brigade, 3rd Infantry Division, drove into Baghdad. He speculates that some of them were using drugs and they were suicidal in their attacks.
BTW, Thunder Run is a fantastic book and a "must read".
every single one of the terrorist killed in the Russian school tragedy in Beslan were shown -on autopsy - to be pumped full of drugs