What do we know about the link between cannabis and psychosis?

In the last few years there have been an increasing number of studies examining the relationship between cannabis and psychosis. This has captured not only the attention of the research community but also the popular media and public in general. Although it is well known that using cannabis can induce temporary psychotic/hallucinatory symptoms this accumulating body of evidence has suggested that there is an association between some youth who use cannabis regularly and enduring psychosis. Several recent studies suggest that frequent cannabis use during adolescence is associated with a clinically significant increased risk of developing schizophrenia and other mental illnesses which feature psychosis.

Some of the headlines about these studies in the media may be leading the everyday reader to believe that there is a direct casual relationship between marijuana and psychosis, i.e. that the average person who smokes some pot may become psychotic. Though this definitely makes for a gripping news story and there are some studies that suggest this causal link, according to the abundance of scientific literature and various other forms of information (e.g. web and print-based resources, anecdotal evidence, documentaries evidence) the nature of the link between the two seems to be more complicated than this. Before we take a closer look at this link, let's first review the basic facts about psychosis and cannabis.

Next >