Cannabis and alcohol abuse : subtle cognitive effects

The use of both alcohol and cannabis is prevalent in Australian society. An increasing body of research exists, which raises the possibility that certain types of drug taking behaviours related to these substances may be linked to subtle lasting decrements in a variety of cognitive processes. Event Related Potentials (ERPs) represent a highly sensitive and non invasive tool to assess the processes underlying attention and information processing. Of particular interest are the Mismatch Negativity (MMN) and P300 components of the ERP which have been used to reveal deficits related to long-term cannabis use and binge alcohol drinking. Evaluation of the current body of research allows the conclusion that the use of these drugs in combination, a common behaviour, may cause additive and synergistic deficits in cognitive functioning.