Bill: I expect you were stimulated to ask your question about Crystal Methamphetamine upon reading today's Globe and Mail. Here are a couple of sites which provide some answer to your question in relation to PD-like effects. They are not particularly informative, as they only make statements without any supporting references. However, the first one has institutional credibility, and may be the source of the statement in the G&M. http://165.112.78.61/Infofax/methamphetamine.html http://www.hyperreal.org/drugs/stimulants/amphetamine.info The following sites give some information without any comment about PD: http://www.drugs.indiana.edu/publications/iprc/factline/ampet.html http://www.kci.org/meth_info/sites/meth_facts2.htm http://www.elks.org/drugs/da_meth.cfm http://www.nida.nih.gov/NIDA_Notes/NNVol11N5/Tearoff.html http://165.112.78.61/DrugPages/Methamphetamine.html These may give you some direction for further digging. Rgds Roger Buxton