The relation is examined between increased sensitivity to stress associated with noradrenergic hyperactivity and dopaminergic changes, and susceptibility to subsequent spontaneous recurrences of methamphetamine (MAP) psychosis (i.e., flashbacks). Plasma monoamine metabolite levels were assayed in 23 flashbackers, 19 nonflashbackers with a history of MAP psychosis, 10 subjects with persistent MAP psychosis, and 21 MAP user and 9 nonuser controls. All 23 flashbackers had undergone frightening stressful experiences during previous MAP use. Mild psychosocial stressors then triggered flashbacks. The 12 flashbackers with further episodes had markedly increased norepinephrine levels and slightly increased plasma levels of 3-methoxytyramine, an index of dopamine release. While the 11 flashbackers with a single episode displayed small increases in norepinephrine and 3-methoxytyramine levels. Thus, robust noradrenergic hyperreactivity, involving increased dopamine release in response to mild stress may predispose to further episodes of flashbacks.