Abstract
We analyzed monoamine metabolites concentrations in blood plasma of flashbackers who had a history of methamphetamine(MAP) abuse. Subjects were composed of 12 flashbackers, 8 non-flashbackers, 13 MAP users who were not experienced MAP psychosis, and 15 MAP non-users. Flashbackers and non-flashbackers had previously all experienced MAP psychosis. Flashbacks were mostly triggered by mild fear of other people. Plasma norepinephrine(NE) levels were higher in 12 flashbackers during flashbacks than during periods of normalcy. Also plasma NE levels during flashbacks were higher than those in the 13 users and 15 non-users. Plasma NE levels in flasbackers during periods of normalcy were higher than those in the 13 user controls. Other monoamine metabolites concentrations in blood plasma were not significantly different among the subject subgroups. These results suggest that repeated MAP use with threatening experiences may produce sensitivity of neurotransmitter systems including noradrenergicsystems to psychosocial stressors at pharmacologic levels. An increase in peripheral noradrenergic activity may be related to occurrence of flashbacks.
