Individuals affected by substance use disorders have been repeatedly shown to exhibit impaired stop-signal inhibition66–68, as well as deficits in go/no-go performance.69, 70 These impairments appear to be both an antecedent risk factor for, and consequence of, drug use. Unaffected relatives of substance-dependent probands display longer stop signal reaction times,68, 71 suggesting that impaired response inhibition measured using this task is a preexisting heritable endophenotype for addictions. Conversely, a history of cocaine self-administration is sufficient to elicit deficits in stop signal performance in monkeys.72
