[Cognitive deterioration after consumption of cannabis]

The use of cannabis in humans causes several malfunctions in the cognitive performance, but it remains unclear if these alterations are reversible after the abstinence.

The author carries out a wide bibliographical review from the first studies including a large number of subjects, which results are not reliable due to methodological defects. Recent researches, using more strict criteria and modern techniques of neuroimaging, show a subtle and permanent fail in several cognitive functions.

We consider that long term cannabis use (more than 15 years) would lead to a subtle and permanent impairment in cognitive performance, mainly in the capacity of retain new information (probably due to inability to filter tangential information).