Paranoia in methamphetamine (MA) users is not well characterized or understood. To investigate this phenomenon, we created the Methamphetamine Experience Questionnaire (MEQ), and tested its reliability and validity in assessing MA-induced paranoia. We administered the MEQ to 274 MA-dependent subjects. Of the total subjects, 45% (123) first experienced paranoia with MA use; 55% did not. Obtaining or using a weapon while paranoid was common (37% and 11% of subjects with MA-induced paranoia, respectively). Test-retest and inter-rater reliability for MA-induced paranoia showed substantial agreement (kappa = .77, p < .05 and kappa = .80, p < .05, respectively). First episodes of paranoia occurred more often with intravenous use of MA, and subsequent episodes at higher doses. There was modest correlation between paranoia on the MEQ and the Brief Symptom Inventory (BSI) paranoid ideation scale (rho = .27, p < .05). As expected, there was a poor correlation between paranoia on the MEQ and the BSI depression scale (rho = .14, p = .07). The MEQ provides useful information on drug use variables that contribute to paranoia commonly associated with MA use. (Am J Addict 2010;00:1-14).
