Empirical evidence of the profile of methamphetamine withdrawal and procedures to manage the syndrome are in the relatively early stages of development and there are currently no established pharmacological treatments. A number of studies were therefore conducted with the intention of informing the clinical management of methamphetamine withdrawal. A review of previous observations led to a self-reported instrument that was used to explore symptoms and components of the syndrome. The instrument also included a selection of direct effects and a previously validated withdrawal scale as an internal reference. A factor analysis revealed a three-component structure consisting of positive effects, anxiety and fatigue symptom clusters. The anxiety component included symptoms of arousal, including symptoms previously associated with direct effects, while the fatigue component consisted of symptoms of generalised depression. Methamphetamine withdrawal therefore appears to be a complex syndrome rather than simply a rebound from direct effects of the drug. The anxiety and fatigue components were combined to form a composite withdrawal scale (ACSAR-CW), which was found to have satisfactory reliability and validity as a measure of withdrawal severity. Analysis of the time course of methamphetamine withdrawal indicated peak severity during the initial 4 days of abstinence and significant recovery after 7 to 10 days of abstinence. Overall symptoms, particularly those of the anxiety component, remained above normal levels, suggesting that on-going clinical contact may be required. A reliable and valid clinician-rated amphetamine withdrawal scale (CAWS 2.1) and a high performance liquid chromatography method measuring methamphetamine and mirtazapine levels in oral fluid were developed. These measures were applied to a double-blind placebo-controlled trial of the antidepressant mirtazapine in the management of methamphetamine withdrawal among out-patients.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - 2010|