These GO and STOP controls are in the “old” brain – where survival and automatic body functions, emotions and habits reside. Psychoactive drugs activate the GO switch creating the desire to repeat the behavior. “An addictÂ’s MORE is a lot more.” Perhaps even 1000 times more. Once the GO switch is on, it stays on; there is no feedback to stop. The massive amounts of dopamine released by all addictive substances (and behaviors) actually causes destruction of the part of the brain and neurons involved with the STOP switch. So it can be very physically hard for an addicted person, who has modified or damaged parts of their brain, to stop. On the positive side, after the use of addictive substances is stopped, the brain can make new connections and begin to rebuild damaged structures.