perspective, a core set of neuroadaptations involving (perhaps) orbital and ventromedial frontal cortical dysfunction, reductions in brain dopamine D2 receptor signaling and/or altered serotonergic transmission that results from genetic or early environmental mechanisms OR from experience with the pharmacological effects of drugs of abuse result in a pattern of impulsive action and choice that are due to shared mechanism. This is an important hypothesis to test, whether it proves to be correct or incorrect.
