The levels of use of opioids, amphetamines and cocaine and associated levels of harm: summary of scientific evidence

This report presents the findings of a literature review to identify the most frequently occurring patterns of use and their relation to harm in users of opioids, powder and crack cocaine, and meth/amphetamine. The behavioural factors that were studied included: frequency of use, duration of use, routes of administration, drug type, dose, severity of dependence, and (the presence of) polydrug use.