Noradrenergic activity and spontaneous recurrence of methamphetamine psychosis.

The process that triggers flashbacks due to previous methamphetamine (MAP) psychosis was studied in 28 flashbackers, along with 84 non-flashbackers with a history of MAP psychosis. We measured plasma monoamine metabolite levels in 12 of the flashbackers and eight of the non-flashbackers, along with 28 normal controls. Most flashbackers had undergone frightening experiences during previous MAP use. The dominant triggering factor was a mild fear of other people. Plasma norepinephrine (NE) levels in the 12 flashbackers were increased during flashbacks. Thus, MAP use associated with threatening experiences may have increased sensitivity to stressors, leading to the occurrence of flashbacks, including exaggerated noradrenergic activity.